There are 2.7 million miles of public roads in the United States, and in the past we’ve seen several innovative designs that transform these paved surfaces into energy and heat-generating solar roads. One company, Solar Roadways, has even come up with a prototype solar panel for roads, however they are expensive ($7,000 each) and it has been estimated that the cost for transforming the whole country’s roads solar would top $35 trillion. Faced with this is ridiculous cost, the University of Rhode Island has come up with four feasible methods for super-charging our roads with solar power – read on for a look at each!
Read more: Four Solar Road Designs Unveiled by University of Rhode Island | Inhabitat - Green Design Will Save the World
The first method is to gather solar energy from Jersey Barriers, the walls that are often used to separate opposite lanes on narrow roads. The research team from the University believes that if flexible photovoltaic cells were installed along the tops of these barriers, then the energy collected could be used to power street lights and road signs.
“This is a project that could be implemented today because the technology already exists,” said K. Wayne Lee, URI professor of civil and environmental engineering and the leader of the team. “Since the new generation of solar cells are so flexible, they can be installed so that regardless of the angle of the sun, it will be shining on the cells and generating electricity.”
Friday, April 29, 2011
There are 2.7 million miles of public roads in the United States, and in the past we’ve seen several innovative designs that transform these paved surfaces into energy and heat-generating solar roads. One company, Solar Roadways, has even come up with a prototype solar panel for roads, however they are expensive ($7,000 each) and it has been estimated that the cost for transforming the whole country’s roads solar would top $35 trillion. Faced with this is ridiculous cost, the University of Rhode Island has come up with four feasible methods for super-charging our roads with solar power – read on for a look at each!
Researchers from North Carolina State University have developed a sensor that allows engineers to assess the scour potential of soils at various depths and on-site for the first time – a technology that will help evaluate the safety of civil infrastructure before and after storm events. Scour, or erosion of soil around structures due to water flow, is responsible for a wide range of critical infrastructure failures – from unstable bridges to the levees that gave way in the wake of Hurricane Katrina.
The ‘in situ scour evaluation probe’ (ISEP) is the first technology that allows technicians in the field to measure the scour potential of soils without the need for excavation,” says Dr. Mo Gabr, a professor of civil, construction and environmental engineering at NC State and co-author of a paper describing the new device. “Previous technologies required engineers to take samples and process them in a lab.”
Understanding scour potential is important because it can help authorities prepare for, or minimize the impact of, events such as the failure of the levees in the wake of Katrina. Scour has also been linked to approximately 60 percent of the bridge failures in the United States, as documented by the Federal Highway Administration.
“The ISEP’s ability to measure scour potential at different depths helps us predict how the soil will behave in the future as a support media, as various layers of soil are eroded or scoured,” Gabr says.
The ISEP will also allow end-users such as federal and state agencies and private consultants to perform scour assessment more frequently, since they will not have to take physical samples back to a lab for analysis. More testing data means researchers will have a larger data set to work with, which should help them to more accurately predict scouring rates and behavior
The new probe uses a water jet to burrow a hole into the soil. Researchers can track the rate at which the water displaces the soil to determine the scour rate. Researchers can also manipulate the velocity and flow rate of the water to simulate various natural events – from normal stream flow to hurricane-induced surges.
The researchers plan to take the ISEP to North Carolina’s Outer Banks later this month to help with research efforts related to dune erosion.
ICE has played a central role over the course of this study, directly with IUK and through the creation of an independent Stakeholder Reference Group - led by President Peter Hansford - which has facilitated input from all facets of industry.
Commenting on the Implementation Plan, Peter Hansford said:
“ICE welcomes the implementation plan and has been delighted to lead the stakeholder group that has worked with IUK to develop it. Reducing infrastructure costs could save government and private investors billions of pounds - or, more can be built with the same level of funding, benefitting society as a whole. This would be a worthy objective at any time, but during a time of austerity delivering “value for money” has never been more important.
“For the measures in the plan to be successful it will require the public and private sectors to continue to work together, therefore ICE will be coordinating a series of implementation groups, each headed by a “champion” drawn from across industry. These designated working groups will be the focus for collaboration going forwards.”
The following three groups and champions have been established. Peter Hansford, as Chair of the Infrastructure Stakeholder Steering Committee, will oversee these groups and further implementation groups may be formed in the future if required.
1. Infrastructure Client and Procurement Group – Simon Kirby, Director Investment Projects, Network Rail
The Infrastructure Client and Procurement group will encourage more effective application of competition to realise cost savings and growth through the supply chain and minimise wastage in procurement processes. This group will also promote procurement approaches and contract form selection that properly consider clients' risk appetite and commercial capability.
2. Infrastructure Data Group – Professor Brian Collins, Chief Scientific Advisor, Department for Transport & Department for Business Innovation and Skills
The Government will work with the Infrastructure Data Group to establish a top-down approach and protocols to assure the robustness of departmental asset and condition records. Through the Infrastructure Data Group the Government will develop a means to capture post project cost information and improve access to international data, working with the Construction Sector Transparency (CoST) initiative.
The three finalists, Hisanao Kajiura (Kaji), Maisie Wong and Nick Holt all presented and defended their projects at One Great George Street in London. All three demonstrated in depth understanding of engineering principles in design and construction, reflecting Rennie’s values, but it was Kaji who won the Award.
Kaji told ICE: “I am extremely happy to have won this year’s James Rennie Medal. I really can’t find the words… I would definitely want to thank my friends, family and all my colleagues at TAISEI, HPR (High Point Rendel) and Arup who have supported me. This has been such a challenging yet rewarding experience. I cannot emphasise how proud I am to have won such a prestigious award.” Kaji will be presented with the medal and £500 cash prize at the ICE Annual Awards Ceremony later in this year.
A great achievement
The finalists were selected from nearly 1,000 of their peers because of their outstanding qualities in all attributes and their significant contribution to the promotion and development of civil engineering.
More about the presentations
Kaji: Make the Impossible Possible
Kaji’s project, ‘Make the Impossible Possible’ talked about how a civil engineer contributes to achieving the aims of a project and demonstrated the benefits of being a construction professional whilst working on the Djibouti Hotel, North Africa.
Maisie Wong: Challenges in Uganda
Maisie focussed on her work in Uganda on the Soroti Medical Center and the CASSO Orphanage Project. She highlighted the challenges faced regarding heath, safety and welfare and some of the key technical and commercial difficulties she overcame for construction in a developing country.
Nick Holt: Live rails and a youth club
Nick’s inspiring presentation 'Liverpool University Engineering Restructuring Project/Wigan Boys and Girls Youth Club’ focused on the technical challenges he encountered while designing the university’s new engineering department, which was constructed above live rail lines, and the project management challenges he faced while managing the design of the Wigan Boys and Girls Youth Club.
The nine junior faculty members in CEE organized the first CEE Research Speed Dating Day, which was held Friday, Feb. 11, from 1 to 6 p.m. The event consisted of 22 five-minute sound bite presentations each on a single research topic and each followed by three minutes of Q&A.
Presentations were divided evenly between postdoctoral researchers, senior faculty and junior faculty. The goal was to broaden connections, foster dialogue, increase the cross-section interactions and establish research relationships within the department. This new forum will be repeated annually or bi-annually and ultimately allow all faculty members and postdoctoral associates to present.
Natural ecosystems need nutrients, such as phosphorus and nitrogen, to sustain plant life. But too many nutrients running into water bodies from fertilized farms and lawns or from wastewater can over-fertilize algae and aquatic plants and cause a major environmental problem called eutrophication. Waters may become fouled with scum, and the eventual bacterial decay of the plants and algae can deplete oxygen, which in turn kills fish and leads to dead zones, like those in the Gulf of Mexico and the Baltic Sea, toxic red tides in coastal waters, and cyanobacterial blooms in lakes and rivers.
Efforts to prevent or reverse eutrophication in freshwater typically aim to decrease the amount of phosphate entering the lake or river in runoff from the watershed. But a new CEE study suggests that phosphate control measures that simultaneously decrease nitrate inflow could, paradoxically, result in an increased release of phosphate from lake sediments that have become enriched after years of heavy phosphate inflow. Incorporating this information into engineering models of lake eutrophication could make them more accurate and useful.
“We observed that nitrate plays a role somewhat analogous to oxygen at our study site. So, counterintuitively, a lake with less nitrate inflow might have more phosphate released back into the water from the sediment,” said Harry Hemond, the William E. Leonhard Professor of Civil and Environmental Engineering. Katherine Lin ’05, who worked with Hemond on this research, was at the time an undergraduate student participating in the Undergraduate Research Opportunities Program at MIT.
Their study, which appeared in the June 2010 issue of Water Research, looked at the Upper Mystic Lake, a freshwater lake about seven miles from the MIT campus that is fed by the Aberjona River and feeds into the Mystic River and Boston Harbor. Over centuries, arsenic and other toxins from surrounding industry have accumulated in the lake sediment, and the lake has also become eutrophied from nutrient runoff.
The researchers focused on the water chemistry at the lake bottom because the intent was to study the potential release of nutrients from the lake sediment. Specifically, they looked at how the iron redox cycle (sometimes dubbed the “ferrous wheel”) controls phosphate cycling between the sediment and the water.
In this cycle, insoluble oxyhydroxide iron (III) particles in the water absorb phosphate and drag it to the sediment, preventing it from promoting algal growth. However, iron in the sediment can be chemically reduced into ferrous iron (II), which dissolves and releases its absorbed phosphate back into the water, thus promoting eutrophication. Oxygen in the water, however, can react with this soluble ferrous iron to recreate oxyhydroxide iron (III) particles, which reabsorb phosphate and settle back to the sediment.
Kenneth H. Stokoe, Professor in geotechnical engineering, was selected by the ASCE as the Karl Terzaghi Lecturer for 2011. The lecture recognizes an individual for their exemplary contributions to the field of soils and geomaterials and is the highest honor that a geotechnical engineer may receive.
Established in 1960, the Soil Mechanics and Foundation Engineering Division of the ASCE (now known as the Geotechnical Engineering Division), created this lecture series to honor Karl Terzaghi, the father of the profession, by annually recognizing the contributions of a peer in the field of geotechnology.
Stokoe gave the Terzaghi Lecture at Geo-Frontiers in Dallas on March 15, 2011.
CEE alumna Kathryn Mallon, left, with EE&S chair Professor Charles J. Werth, pictured at the Levis Faculty Center, where Mallon delivered the keynote address for the environmental area's Spring Symposium.
What do you do when a tunnel that provides half the water supply to New York City is leaking? What do a water treatment plant and the nicest driving range in the Bronx have in common? How do you increase sustainability in a concrete jungle with 8.2 million people?
CEE alumna Kathryn Mallon, P.E., (BS 88) answered these questions and more during her keynote address, “Really Cool Engineering Challenges Working for the Largest City in the U.S.,” delivered April 1 at the Environmental Engineering and Science (EE&S) Spring Symposium at Levis Faculty Center in Urbana. The symposium is presented annually to showcase the research of graduate students in the department’s EE&S program.
Mallon, who also earned a master’s in environmental engineering from the University of North Carolina at Chapel Hill, works for the New York City Department of Environmental Protection (DEP) in the Bureau of Engineering Design and Construction. As Deputy Commissioner of the agency’s capital delivery program, she manages more than 400 staff focused on the design and construction of $10 billion in water and wastewater capital work for the City of New York. In 2008, after nearly 20 years at MWH Americas Inc., an engineering consulting firm, Mallon joined the DEP, a move that has afforded her “the opportunity to be involved in several lifetimes worth of ‘once-in-a-lifetime projects’,” she said.
Her presentation to the enthusiastic audience of mostly environmental engineering students and faculty included details about the history and scope of the agency’s work, the engineering aspects of undertaking complex projects in a densely populated city with aging infrastructure, as well as insights into the practice of engineering in the public sector, where bureaucracy, politics and government regulations add complexity.
The DEP exists to deliver clean drinking water to New York City residents, treat wastewater, promote clean waterways, improve air quality, reduce noise pollution, and protect against hazardous materials like asbestos and lead. The agency manages a $15 billion capital program with more than 100 active projects that range in size from $10 million to more than $1 billion.
Among the projects Mallon discussed was New York City’s Green Infrastructure Plan. The city is piloting the use of a number of sustainable technologies to slow storm water runoff after heavy rainfall and reduce combined sewer overflow—a unique challenge in a city so heavily built and paved that it is 75 percent impervious. Pilot projects include porous pavements, planting areas in right-of-ways, green roofs and “blue” roofs. A blue roof features a system of gravel-filled, perforated trays, which capture and slowly release rain water. Green infrastructure is more economical and sustainable than traditional “grey infrastructure,” Mallon said.
Stanford researchers have developed a battery that takes advantage of the difference in salinity between freshwater and seawater to produce electricity.
Anywhere freshwater enters the sea, such as river mouths or estuaries, could be potential sites for a power plant using such a battery, said Yi Cui, associate professor of materials science and engineering, who led the research team.
The theoretical limiting factor, he said, is the amount of freshwater available. "We actually have an infinite amount of ocean water; unfortunately we don't have an infinite amount of freshwater," he said.
As an indicator of the battery's potential for producing power, Cui's team calculated that if all the world's rivers were put to use, their batteries could supply about 2 terawatts of electricity annually – that's roughly 13 percent of the world's current energy consumption.
The battery itself is simple, consisting of two electrodes – one positive, one negative – immersed in a liquid containing electrically charged particles, or ions. In water, the ions are sodium and chlorine, the components of ordinary table salt.
Initially, the battery is filled with freshwater and a small electric current is applied to charge it up. The freshwater is then drained and replaced with seawater. Because seawater is salty, containing 60 to 100 times more ions than freshwater, it increases the electrical potential, or voltage, between the two electrodes. That makes it possible to reap far more electricity than the amount used to charge the battery.
"The voltage really depends on the concentration of the sodium and chlorine ions you have," Cui said. "If you charge at low voltage in freshwater, then discharge at high voltage in sea water, that means you gain energy. You get more energy than you put in."
John Voekel wins seekingShade Student Design Competition, which challenged participants to conceive a shade structure for the forthcoming pedestrian bridge at the US Land Port of Entry in San Ysidro, CA.
John is a dual degree candidate at UC Berkeley pursuing a Master of Science in Structural Engineering and a Master of Architecture.
His proposal features a series of tetrahedral-shaped, modular shading devices arranged along the pedestrian bridge. Each module is comprised of canvas fabric stretched across lightweight steel frames. While the southern edge of each component is fastened to the bridge and provides pedestrians protection from the sun, the northern edge rotates freely and responds to breezes uniquely. The result is that the bridge appears to flutter as the wind blows and subtly links pedestrians to the environment surrounding them
Built by S&A Homes in partnership with IBACOS, the Best Practices Research Alliance (BPRA) Lab Home is a net-zero energy home, expected to pave the way toward eradicating homeowner's energy bills.
The four-bedroom home will serve as a life-sized laboratory over the next three years as experts monitor multiple HVAC systems and building practices. S&A Homes and IBACOS hope to prove that a family-friendly home that blends into a typical neighborhood can stand out in terms of energy usage and environmental friendliness.
"S&A has been dedicated to innovations over the last 20 years and the lab home is simply the next step in the evolution towards achieving the ultimate in energy efficient homes," said Chris Schoonmaker, Vice President of Sales at S&A Homes. "We also understand that no matter how much a homebuyer wants to save on energy bills or help the environment, homes must be affordable, stylish and in the right location."
While not at net-zero, the S&A E-Home, debuted in 2009, cuts the average homeowner's monthly energy bills by $150 when compared to similarly sized, 10-year-old homes. Some of the ENERGY STAR™ qualified E-Home's features include 2x6 exterior construction, ultra low-e windows, 90% CFL lighting, high performance HVAC systems and recycled materials.
The Lab Home takes energy efficiency to a new level by incorporating innovations like a horizontal loop ground source heat pump system. The Home's 8" thick exterior walls, built from staggered 2x4s and filled with R-40 insulation, introduce another innovation that provides extra protection from Northeastern winters. Solar panels gather energy during the summer to power the home, plus earn credit on utility bills. The credit should pay for energy during winter months, essentially equaling zero energy used.
The Smart-Way Disposal & Recycling Company Ltd. has developed several new products and services to complement its line of waste and recycling solutions for commercial and residential customers.
The first new product called the Flying Bin Contraption ("FBC") was designed to address the special needs of homebuilders and contractors on jobsites with limited space. The FBC allows customers to have a scheduled pick-up service on smaller residential construction lots. It also works extremely well to control and handle waste and recycling materials on commercial sites where access is awkward such as high rise tower construction projects, large scale renovation jobs or multi-level housing complexes.
Smart-Way has also developed a system for use in the concrete industry. This is a specialized polyethylene bag designed to capture the left-over concrete from concrete pumpers used on residential and commercial jobsites. This bag provides a solution for the pumper and contractor to maintain a clean and therefore safe jobsite while diverting the excess concrete to recycling instead of to a landfill.
Another new product is called the E-Z-Bag. The E-Z-Bag is designed to provide customers with smaller volume waste requirements and/or limited space with an affordable solution for disposal. The customer pre-purchases the polyethylene bag to fill with their waste and then calls Smart-Way for pickup and transport to an accredited regional landfill. The E-Z-Bag is a simple yet very effective solution for customers such as residential homeowners looking to dispose of unwanted household items, people who are moving and want to get rid of belongings prior to moving, renovators that have short term limited volume waste or any other application that does not require the larger roll-off bins available in the Smart-Way fleet.
At Ecobuild 2011 Accsys Technologies have showcased their high technology wood products, including Accoya® wood, which is created from sustainably sourced softwood and matches or exceeds the beauty and quality of the very best tropical hardwoods.
Accsys Technologies used their exhibition space to demonstrate the varied applications of Accoya® wood throughout the world.
Leaders in the field of sustainable modified wood, Accsys Technologies also had a wall dedicated to the world’s first Medite Tricoya® panel, the new panel product being developed in conjunction with Coillte Panel Products. Unveiled at Ecobuild 2010, the Medite Tricoya® panel has been hailed as one of the first true innovations in the wood composites industry in more than 30 years, marking the beginning of the next generation of wood-based panel products for outdoor use
2010 was a record year for Accoya®, which has seen increased sales and global reach
On a steamy morning June 2006, less than a year after Hurricane Katrina, I sat in a packed ballroom at a hotel in downtown New Orleans to hear the commander of the U.S. Army Corps of Engineers take the podium and accept blame for the single biggest civil engineering failure in American history.
It was a stunning admission.
For months, members of the Corps had blamed the massive breakdown of the city's levee system on mother nature.
But now a 6,000-page report that cost the Defense Department more than $20 million had said its own Corps had built levees and floodwalls that were "a system in name only," incomplete, inconsistent and with design performance flaws.
"We do take accountability," Lt. Gen. Carl Strock said. "It's been sobering for us," he added to "have to stand up and say: We had a catastrophic failure of one of our projects."
A second and a third independent investigation had similar findings. One even went so far as to say the Corps took short cuts in building the levees to save money.
In the five years since those levees failed -- flooding 80 percent of New Orleans and killing more than a thousand people -- the federal government has spent $15 billion trying to fix what went wrong.
The Army Corps of Engineers is, at Congress's direction, constructing what it says is a flood protection system rated for 100 years -- in other words, able to withstand a storm likely to occur once every 100 years on average. The Corps says the system has some resiliency up to the level of a once-every-500-years storm.
Twelve miles from New Orleans at Lake Borgne, the Corps is building a massive wall 26 feet high and two miles long. That's where the huge post-Katrina storm surge pushed water down a ship channel dredged years earlier by the Corps, resulting in some of the worst flooding in St. Bernard Parish and areas of East New Orleans.
On August 1, 2007, the I-35W Mississippi River Bridge in Minneapolis suddenly collapsed, sending mangled steel from the superstructure and crumbled concrete slabs from the paved deck tumbling down into the river. The rush-hour disaster resulted in 13 deaths and caused injuries to another 145 people.
Spectacular collapses such as this reverberate around the globe. So do expressions of concern about our aging infrastructure and calls to “do something about it.” To civil engineers, “failure” actually occurs much earlier than an ultimate collapse. A structural failure means that part of the structure has lost its capacity to carry the loads it was designed for or that some of its members experience bending or deformations beyond acceptable tolerances.
Tianwei “David” Ma of UH Mānoa's Civil and Environmental Engineering Department received a research grant from the National Science Foundation to perfect a method of harvesting energy from the natural motion of bridges to power smart monitoring devices. The $223,000 grant runs to April 2011.
Effective and continuous monitoring of civil engineering structures can provide timely warning that can help avert failures and ultimate collapses, just like preventive medicine. With advances in technology, wireless sensors are replacing traditional “tethered” (or hard-wired) networks.
As Ma puts it, “the use of wireless sensor networks in structural health monitoring is greatly hindered by the need to provide reliable power sources for them; batteries need to be replaced to ensure that the network is always up and running.” “Structures such as bridges,” he continues “are not just sitting still all the time as many people assume; they are almost always vibrating very slightly due to moving traffic and wind loads.”
Five years after Hurricane Katrina devastated New Orleans, James N. Jensen, UB professor of civil, structural and environmental engineering, says that probably the biggest lesson learned from that disaster was that municipalities and citizens now take orders to evacuate much more seriously.
Jensen was one of six UB researchers who visited the Gulf Coast soon after Katrina hit as part of a National Science Foundation-funded reconnaissance mission organized by UB's Multidisciplinary Center for Earthquake Engineering Research. Research into “extreme events” and disaster mitigation/response is a strategic strength of the university identified in the UB 2020 strategic plan.
“By the time Hurricane Rita hit not long after Katrina, there was something like a 95 percent evacuation rate,” Jensen recalls. “People had really gotten the message.”
During his visit to New Orleans in October 2005, Jensen and colleague Pavani Ram, assistant professor of social and preventive medicine, met with public-health officials and with managers from wastewater treatment plants.
While he said that drinking water was restored by about 10 weeks after Katrina, one major problem persisted as a result of the loss of pressure of water distribution systems due to shifting, waterlogged houses and empty cars on flooded streets that knocked down fire hydrants.
“They estimated that as many as 1,000 or more breaks occurred in the water distribution pipes due to the damaged fire hydrants,” Jensen says, “and the loss of pressure that resulted led to contaminating the water in those pipes.”
Another issue, one that could complicate hurricanes this season, is the problem posed by the potential loss of vegetation in wetlands due to the Gulf oil spill.
Carnegie Mellon receives Funding To Create New Program Studying Environmental İmpact Of Nanotechnology
PITTSBURGH—Researchers at Carnegie Mellon University and Howard University in Washington, D.C., have received a five-year, $3.15 million grant from the National Science Foundation (NSF) to launch a new interdisciplinary program in the environmental affects and policy implications of nanotechnology.
Funding comes from a new NSF program called the Integrative Graduate Education and Research Traineeship (IGERT), which enables the creation of interdisciplinary programs educating U.S. Ph.D.s in science and engineering.
"The IGERT program at Carnegie Mellon and Howard will operate at the interface of science and environmental policy to produce an environmentally and policy literate generation of nanoscience professionals with the skills needed to create novel nanotechnologies and to assess and manage environmental risks associated with nanomaterials," said Jeanne M. VanBriesen, professor of civil and environmental engineering at Carnegie Mellon who will lead the program.
Graduate students from multiple disciplines will participate in a two-year training program to learn the fundamentals of their core disciplines and gain proficiency in the analysis of environmental issues pertaining to nanotechnology, decision science and policy analysis in new nanotechnology-themed courses. Following this foundation, students will conduct research at the interface of policy and nanotechnology. Students also will participate in international laboratory exchange projects as well as internships at corporations active in nanotechnology.
VanBriesen will be joined in the program development and implementation by a cadre of professors including: Gregory Lowry, professor of civil and environmental engineering at Carnegie Mellon and associate director of the Center for Environmental Implications of Nanotechnology CEINT; Elizabeth Casman, associate research professor of engineering and public policy at Carnegie Mellon; and Kimberly L. Jones and Lorraine Fleming, both professors in civil and environmental engineering at Howard University.
Additional Carnegie Mellon faculty participants in this NSF-funded project include: Allen Robinson, professor of mechanical engineering; Kelvin Gregory, assistant professor of civil and environmental engineering; Kris Dahl, assistant professor of biomedical engineering and chemical engineering; Michael Bockstaller, associate professor of materials science; Mohammad Islam, assistant professor of materials science and chemical engineering; and Paul Fischbeck, professor of social and decision sciences and engineering and public policy. Additional Howard faculty participants include Gary Harris, professor of electrical and computer engineering.
Floods cut down more bridges than fire, wind, earthquakes, deterioration, overloads and collisions combined, costing lives and hundreds of millions of dollars in damage.
The speed and turbulence of an overflowing stream scours away the river bottom that provides the support for a bridge foundation, causing more than 60 percent of bridge failures in the U.S. in the last 30 years.
Currently, "there is no way to determine risk during these crucial events," said Xiong "Bill" Yu, an assistant professor of civil engineering at the Case School of Engineering.
To change that, Yu has begun designing what he calls smart infrastructure: underwater sensors that relay real-time information about how much river bottom has been stripped away and how stable, or unstable, the supports of a bridge remain. His work is being funded by a $450,001 CAREER grant received from the National Science Foundation in 2009.
"We don't fully understand how scouring takes place," Yu said. Water passing a bridge support forms vortices, which erode the river bottom. But how and at what rate scour occurs is complex. River bottoms usually consist of sand, clay, shale or sandstone or a mix, and each material acts a little differently in a strong current, he explained.
To characterize each vortex, Yu's lab is building flow sensors based on tiny, hair-like sensors that salmon have on the sides of their bodies. Researchers have found the fish determine flow direction by the direction the hairy cells move and speed by the time delay as turbulence passes different sensors. Yu's lab built sensors comprised of micro pillars made with piezoelectric fibers mounted on flexible copper rods. The fibers produce electric signals reflecting flow direction and speed. These have proven sensitive and accurate; the lab is now developing arrays for real-time flow and turbulence sensing.
To determine the amount of sediments being scoured away, his lab has built sensors that constantly measure the topography where the water meets the river bottom around the bridge supports. These sensors employ a technology called time domain reflectometry, in which radar is fired along waveguides installed at critical ground locations. The electromagnetic waves return at different speeds depending on the materials they strike and distance traveled. The waves are analyzed with an algorithm developed by Yu's lab to reveal minute changes in the depth and density of the substrate sediments.
It's called microbiologically influenced corrosion, also known as MIC. In a report released by the San Francisco Chronicle Friday morning, investigators will see if that may be a cause in the San Bruno explosion.
MIC is believed to be the cause of a deadly explosion in New Mexico, 10 years ago. A gasline ruptured in the desert, killing 12 people. After looking at the wrecked pipeline, investigators found destructive microbes, which can lie dormant and undetected for years, in an underground pipeline. Then without warning, can spring to life and start eating and corroding the metal. The pipeline in New Mexico was over 50-years-old, and 30 inches in diameter.
The pipeline in San Bruno that ruptured on September 9 was over 50-years-old and 30 inches in diameter.
According to the Chronicle, PG&E told state regulators last year that there was "ongoing concern" about the potential for internal corrosion, along the 46 mile pipeline, which ran from San Francisco, through San Bruno, down to Milpitas.
The sign of corrosion-causing microbes had shown up in several tests along the line. Experts, not associated with PG&E, confirm it's very likely pipelines, as old as 50-years-old, could have microbes in it.
The only way to check is by sending robots called smart pigs, or cleaning pigs, to detect any cracking in the walls, or to remove any gunk along the walls. But they don't fit into narrow pipelines, like the one in San Bruno.
A professor of civil engineering at USC disagrees to parts of the report, saying it's unlikely the cause is internal corrosion.
Thursday, April 28, 2011
The Hoover Dam bypass bridge looks spectacular, stretching 1,900 feet across Black Canyon and 900 feet above the churning Colorado River. Tourists visiting the world-famous Hoover Dam can't help but swing around and snap photos of the new span high above.
Long before its completion, it was labeled a "civil engineering marvel."
Perhaps the toughest challenges associated with building the long-awaited bridge linking Arizona and Nevada had less to do with technology and the daunting dimensions and more to do with respecting the true engineering marvel 1,500 feet upstream. At least that is the opinion of one well-respected civil engineer.
"I think the challenge was to make it come up to the iconic standards of the Hoover Dam, building something in such close proximity to a world-class structure like that," said Henry Petroski, a civil engineering professor at Duke University. "The engineers involved were very conscious of this, that they were working with a site that had to be respected."
Wednesday, April 27, 2011
For the past few years, one of the most common questions facing the Texas Water Development Board (TWDB) hasn’t been over contentious water rights or proposed water projects; it’s been from homeowners wanting to know what type of roofing material is most suitable for collecting rainwater for indoor domestic use.
“Rainwater harvesting is becoming fairly widespread, at least in Central Texas. There’s interest born out of necessity because people are simply running out of water in rural areas or they’re interested in conserving water supplies and it’s good for the environment,” said Dr. Sanjeev Kalaswad, the TWDB’s rainwater harvesting coordinator.
But when it came to responding to residents’ questions about which roof collection surfaces are best suited for rainwater harvesting, TWDB didn’t have a good, science-based answer to give, Kalaswad said. That’s when the Cockrell School of Engineering came in to help.
With funding from TWDB, Cockrell School faculty and students conducted an in-depth study - recently published in the academic journal Water Research - examining the effects of conventional and alternative roofing materials on the quality of harvested rainwater. The study, led by civil, architectural and environmental engineering Assistant Professor Mary Jo Kirisits, showed that, of the five roofing materials tested, metal (specifically Galvalume®), concrete tile and cool roofs produce the highest harvested rainwater quality for indoor domestic use. The study also showed that rainwater from asphalt fiberglass shingle roofs and increasingly popular “green” roofs contain high levels of dissolved organic carbon (DOC). Although other potential pollutants can be significantly lower on green roofs (turbidity and aluminum), the high DOCs are significant where these roofs would be used for potable rainwater collection.
Water with DOC is not necessarily dangerous on its own, but Kirisits said when it’s mixed with chlorine – a common product used to disinfect water – the two substances react to form byproducts that potentially cause cancer and other negative human health effects.
“Someone who already has a rainwater system is probably not going to change their roofing material based on this study, but this information is useful for anyone who’s trying to make an informed decision about what material to use,” Kirisits said.
Over the course of a year, Kirisits, her co-Principal Investigators Professor Kerry Kinney and Research Associate Professor Michael Barrett and their engineering students examined water collected from five roofing materials: asphalt fiberglass shingle, Galvalume®, concrete tile, cool and green roofs.
The test sites included both pilot-scale and full-scale residential roofs — one of which was the roof on the home of Kirisits and her husband. The other roofs were located at or near the Lady Bird Johnson Wildflower Center, where her team had the expertise of the center’s director of research and consulting, Dr. Mark Simmons, who helped them interpret some of their findings.
Study leader Charles Carraher, Ph.D., explained that the more than 450 coal-burning electric power plants in the United States produce about 130 million tons of "flyash" each year. Before air pollution laws, those fine particles of soot and dust flew up smokestacks and into the air. Power plants now collect the ash.
"Flyash poses enormous waste disposal problems," Carraher said. "Some of it does get recycled and reused. But almost 70 percent winds up in landfills every year, where space is increasingly scarce and expensive. Our research indicates that this waste could become a valuable resource as a shield-like coating to keep concrete from deteriorating and crumbling as it ages."
Carraher, who is with Florida Atlantic University, said that the new material can be used to coat and protect from corrosion steel reinforcing bar, or "rebar," rods embedded in concrete to reinforce and strengthen it. The coating also is suitable for repairing damaged concrete. This is part of a joint project between industry (Felix Achille, of Blue World Crete) and academia (Charles E. Carraher, Ph.D., Dept. of Chemistry and Biochemistry; Madasamy Arockiasamy, Ph.D., Dept. of Civil Engineering; and Perambur Neelakantaswamy, Ph.D., Dept. Electrical Engineering and Computer Science).
Laboratory tests have shown that the coating has excellent strength and durability when exposed to heat, cold, rain, and other simulated environmental conditions harsher than any that would occur in the real world, Carraher said. The coating protected concrete from deterioration, for instance, that involved exposure to the acids in air pollution that were 100,000 times more concentrated than typical outdoor levels environment. Coated concrete remained strong and intact for more than a year of observation, while ordinary concrete often began to crumble within days, he said.
Carraher cited U.S. Environmental Protection Agency estimates for the cost for repair, restoration, and replacement of concrete in domestic wastewater and drinking water systems. They range up to $1.3 trillion, and by some accounts must be completed by 2020 to avoid environmental and public health crisis problems. Crumbling concrete roads and bridges will require hundreds of billions more.
Use of the coating could extend the lifespan of those structures, with enormous savings, while helping to solve the flyash disposal problem, Carraher noted.
Builders in developing countries are often not required to build strong buildings. So, when a disaster strikes, the damage is often widespread.
Yet Japan is one of the most developed countries in the world. Still, the March eleventh earthquake and tsunami waves destroyed more than fourteen thousand buildings.
Brady Cox is an assistant professor of civil engineering at the University of Arkansas. He is also an earthquake expert with an organization called Geotechnical Extreme Events Reconnaissance, or GEER. The group studies major disasters.
Professor Cox says Japan has one of the best building-code systems in the world.
BRADY COX: "The problem is this earthquake was just a mammoth earthquake, one of the, you know, top five earthquakes in recorded history. So anytime you have an earthquake that large, you are going to have damage."
The quake measured magnitude nine.
BRADY COX: "One thing I think a lot of people don't understand is that building codes are meant to prevent loss of life in earthquakes, that doesn’t mean that the buildings won't -- or bridges for that matter, or anything -- won't sustain significant damage."
Mr. Cox says Japan has invested a lot in seismic research and design since a magnitude 7.5 earthquake in Niigata in nineteen sixty-four. That same year a 9.2 quake shook the American state of Alaska.
BRADY COX: "Those two earthquakes really opened up a lot of new research on something called soil liquefaction, in particular. And, you know, the Japanese, they have more earthquakes greater than magnitude six or seven than probably any other country in the world. I mean, they get hit a lot."
Soil liquefaction is the process by which the strength or stiffness of soil is weakened by an event like the shaking of an earthquake. The soil begins to move like liquid.
Professor Cox says the first step to designing an earthquake-resistant building is to study the soil.
BRADY COX: "Then the structural engineers take that information and they use it to detail the building in terms of, is this going to be a steel structure? Is it going to be reinforced concrete? And then you get into all kinds of things in terms of the designs of the columns and the beams and the framing of the building and the connections. And how much steel do you put in?"
We often take for granted the idea that the buildings we use every day will remain standing. This becomes most apparent during seismic events when the structural capacity of the built environment is put to the ultimate test. Yet the damage caused by extreme earthquakes is highly variable, which is in fact best illustrated by the differences in the destruction caused by recent earthquakes in Haiti and Japan.
Earthquakes will continue to be a natural hazard as long as we continue to live in seismically active areas, so it is worth understanding the reasons why some buildings stay standing and others collapse when exposed to the same risks. Ultimately, that distinction is in the building codes governing construction practices, as well as how the buildings are maintained. Saeed Mirza, professor emeritus in Civil Engineering at McGill, has spent much of his career working on issues related to construction and society. “The devastation we saw in Haiti is what happens when there is no meaningful structural code,” he said. Even though that earthquake was 1,000 times less severe than the recent Japan event, over 200,000 people lost their lives and more than 90 per cent of buildings near the epicenter collapsed.
At their core, what structural codes do is allow designers to determine two things: expected loads, and buildings’ expected ability to resist those loads. Inherent in these estimates (which are based on the best available data and probability) is the risk that we will underestimate the applied loads and overestimate the resistance, leading to failure and possible loss of life. In practice, the way that design engineers minimize that risk is by making their resistance estimates as conservative as realistically possible. For earthquake resistance, the Canadian code ensures that structures will survive small to moderate earthquakes with little to no damage. In the case of larger earthquakes, the design philosophy emphasizes multiple layers of redundancy and types of ductile failures that allow maximum survivability (such as beams that stretch and sag instead of suddenly cracking in half, allowing occupants to escape). The code is strictest when it comes to ensuring that structures needed post-disaster – such as fire stations or hospitals – remain intact even when less critical structures collapse.
The corollary to this philosophy is the fact that less risk necessarily costs more money, and that this relationship is not linear. For post-disaster design, the additional material, design, and construction will increase building costs by 20 to 30 per cent, sometimes even more. Though the question of whether additional safety is worth the money is unpleasant to ask, structural codes exist to ensure that whatever the answer, loss of human life will hopefully be minimized.
How structural codes determine a feasible solution to this problem is highly dependent on location, since the forces that govern structural design are generally region-specific. Snow loads may be particularly troublesome in Eastern Canada – and often control design – but are extremely unlikely in places like Arizona. Likewise, the building code in Japan is notably conservative in respect to earthquake design since the country is particularly seismically active. All of Japan is potentially at risk, so the Japanese structural code requires measures not seen in other countries, such as base-isolated foundations, or multiple redundant structural systems. With these advanced construction practices comes a higher price tag for each building, but the Japanese government has decided that these higher prices are worth the lives saved.
Even the most conservative building codes are not 100 per cent effective, because there is always a chance that the design for “worst-case scenario” will be exceeded. In the wake of such events, the lessons learned help improve our codes, and make future buildings even safer. Though these changes do much to improve the safety of new buildings, they do not affect the state of existing construction. The absolute importance of these changes can be seen in the fact that earthquakes disproportionally effect older buildings, while their modern counterparts perform as intended.
When Princeton senior Maryanne Wachter visited Chicago on a recent class trip, she returned to a childhood fascination.
"I grew up in Louisiana but used to visit my grandmother in Chicago," said Wachter, a civil and environmental engineering major. "That's where I first saw tall buildings and where I decided to be a civil engineer."
Chicago was one of three American cities known for their iconic towers that Wachter and her classmates toured as part of a new Princeton engineering class devoted to the study of the relations of buildings, space, time and societal dynamics. Called "A Social and Multi-dimensional Exploration of Structure," the course was taught for the first time this past fall with a theme of tall buildings. It was developed with funding from Princeton's 250th Anniversary Fund, which supports innovation in undergraduate education, and will be offered at least every other year with a new theme each time.
Taught by Maria Garlock and Sigrid Adriaenssens, both assistant professors of civil and environmental engineering, last fall's class took a holistic approach to the design and construction of soaring towers. In addition to learning about the technical aspects of designing and constructing tall buildings, the students explored how buildings fit into the political, social and economic conditions of their time.
The students learned, for instance, that construction of many of Chicago's skyscrapers was driven by a desire to bring people back into the city in the 1950s and 1960s, while Houston's towers resulted from the city's booming business environment in the 1960s and 1970s.
"A tall building doesn't just come out of nowhere," Adriaenssens said. "There are political and economic forces at work and trends that influence design and construction."
The class focused on the buildings of Fazlur Khan, a Bangladeshi-American engineer who designed some of America's most famous skyscrapers, including the John Hancock Center and Willis Tower (formerly known as the Sears Tower), both in Chicago.
The 11 students in the class -- all civil and environmental engineering majors -- visited buildings built by Khan and others in Chicago, New York and Houston to see the towers firsthand and learn about the circumstances in which they were built and how they've fared over time.
Civil engineers at Oregon State University have developed a new system to better analyze the connections that hold major bridge members together, which may improve public safety, help address a trillion-dollar concern about aging infrastructure around the world, and save lives.
When testing is complete and the technology implemented, the system might allow a technician working for a day to produce a better analysis of a bridge’s structural condition than a more expensive and highly-trained engineer could do in weeks.
Developed at OSU, the technology is being tested this fall by a simulated laboratory failure of the exact type of truss connecting plate that caused a bridge to collapse on Interstate 35W in Minneapolis in 2007, killing 13 people and injuring 145.
The work also brings focus to a little-understood aspect of bridge safety — that most failures are caused by connections, not the girders and beams they connect, as many people had assumed. The issues involved are a concern with thousands of bridges worth trillions of dollars in many nations.
“The tragic collapse of the interstate bridge across the Mississippi River in 2007 brought a lot of attention to this issue,” said Chris Higgins, a professor in the School of Civil and Construction Engineering at OSU. “For decades in bridge rating and inspections, we’ve been concentrating mostly on the members, but in fact it’s the connectors where most failures occur. And the failure of a single critical connection can bring down an entire bridge, just like it did in Minneapolis.”
This is a growing concern, Higgins said, because thousands of bridges were built around the world in the 1950s and later that may be nearing the end of their anticipated lifespan, including many of those on the interstate highway system in the United States. Maintenance, repair and replacement of this infrastructure could cost trillions of dollars, he said, at local, state and federal levels.
But prioritizing which bridges are still safe and which most urgently need repair or replacement is not easy and has never been obvious, Higgins said.
“The failure of the bridge in Minneapolis was caused by a single connecting plate that inspectors saw repeatedly,” Higgins said. “They took pictures of it, actually had to touch it, because an access ladder was right next to it when they were doing inspections.
Finley Charney, a structural engineering associate professor in the civil and environmental engineering department, and Mahendra Singh, the Preston Wade Professor of Engineering in the engineering science and mechanics department, are developing new structural systems that are geared to perform optimally during earthquakes. Singh's background is also in civil and structural engineering, and one area of his expertise is in earthquake engineering.
It's no secret that earthquakes come in all sizes with varying degrees of damage depending on the geographic locations where they occur. And even a small one on the Richter scale that strikes in an impoverished nation can be more damaging than a larger one that occurs in a city where all buildings have been designed to a stricter building code.
And to listen to Charney speak on the subject, attaining acceptable structural performance is a problem even when the current building codes are used as intended for the structural design.
"In my opinion, the current building codes are insufficient because buildings designed according to these codes have evolved only to avoid collapse under very large earthquakes. These same buildings, subjected to smaller, more frequent earthquakes, may have excessive damage, as happened during the 1994 Northridge, California earthquake. I tell my students that good performance for these buildings is not in their DNA," Charney said.
In the future, structural engineers will base their designs on the concepts of Performance Based Earthquake Engineering (PBEE), where the objective is to control damage and provide life-safety for any size of earthquake that might occur. Charney and Singh said they are developing a variety of new structural systems that "will inherently satisfy PBEE standards, yet have negligible damage when subjected to frequent earthquakes, acceptable damage from moderate earthquakes, and a low probability of collapse during the rare, severe earthquake." To achieve their goal, they are creating four new PBEE compliant systems called: hybrid yielding, standard augmented, advanced augmented, and collapse prevention systems.
Charney explained the hybrid yielding system is an improved configuration of an existing system. The key aspect of this enhanced system is that certain components in a structure are designed to yield sooner than what would occur in a traditional system, and other components are designed to yield later. By controlling the sequence of yielding, the dissipation of the seismic energy that comes with the early yielding should allow the structure to meet low-level and mid-level performance requirements, and the residual stiffness provided through delayed yielding will enhance life safety under larger earthquakes.
The standard augmented system will provide an enhanced performance because it utilizes devices called visco-elastic solid or viscous fluid dampers to help control vibrations. "The additional damping provided by these devices is intended to enhance a system's performance primarily at the mid-level limit states," Charney said.
Researchers at Purdue University designed a system made up of heating panels with electrical coils much like giant toaster ovens that are placed close to the surface of large steel beams and other components to simulate fire as they are subjected to forces with hydraulic equipment, a university release says.
Such testing is customarily conducted inside large furnaces.
"However, in a furnace it is very difficult to heat a specimen while simultaneously applying loads onto the structure to simulate the forces exerted during a building's everyday use," Amit Varma, an associate professor of civil engineering, said.
Building fires may reach temperatures above 1,800 degrees Fahrenheit, Varma said.
"At that temperature, exposed steel would take about 25 minutes to lose about 60 percent of its strength and stiffness," he said. "As you keep increasing the temperature of the steel, it becomes softer and weaker."
The heating system is being used to test full-scale steel columns at Purdue's Laboratory for Large-Scale Civil Engineering Research.
Each panel is about 4 feet square, and the system contains 25 panels that cover 100 square feet.
Having separate panels enables researchers to heat certain portions of specimens, recreating "the heating and cooling path of a fire event," Varma said.
It is believed to be the only such heating system in the world, Varma said.
A bacteria that can knit together cracks in concrete structures by producing a special ‘glue’ has been developed by a team of students at Newcastle University. The genetically-modified microbe has been programmed to swim down fine cracks in the concrete. Once at the bottom it produces a mixture of calcium carbonate and a bacterial glue which combine with the filamentous bacterial cells to ‘knit’ the building back together.
Ultimately hardening to the same strength as the surrounding concrete, the ‘BacillaFilla’ – as it has been aptly named – has been developed to prolong the life of structures which are environmentally costly to build. Designed as part of a major international science competition in the US, the students have scooped Gold for their research.
Joint project instructor Jennifer Hallinan explains: “Around five per cent of all man-made carbon dioxide emissions are from the production of concrete, making it a significant contributor to global warming.
“Finding a way of prolonging the lifespan of existing structures means we could reduce this environmental impact and work towards a more sustainable solution.
“This could be particularly useful in earthquake zones where hundreds of buildings have to be flattened because there is currently no easy way of repairing the cracks and making them structurally sound.”
As part of the research, the students have not only considered the advantages of their engineered bacteria, but also the potential risks to the environment.
The BacillaFilla spores only start germinating when they make contact with concrete – triggered by the very specific pH of the material – and they have an in-built self-destruct gene which means they would be unable to survive in the environment.
Once the cells have germinated, they swarm down the fine cracks in the concrete and are able to sense when they reach the bottom because of the clumping of the bacteria.
This clumping activates concrete repair, with the cells differentiating into three types: cells which produce calcium carbonate crystals, cells which become filamentous acting as reinforcing fibres and cells which produce a Levans glue which acts as a binding agent and fills the gap.
Glass stronger and tougher than steel? A new type of damage-tolerant metallic glass, demonstrating a strength and toughness beyond that of any known material, has been developed and tested by a collaboration of researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab)and the California Institute of Technology. What’s more, even better versions of this new glass may be on the way.
“These results mark the first use of a new strategy for metallic glass fabrication and we believe we can use it to make glass that will be even stronger and more tough,” says Robert Ritchie, a materials scientist who led the Berkeley contribution to the research.
The new metallic glass is a microalloy featuring palladium, a metal with a high “bulk-to-shear” stiffness ratio that counteracts the intrinsic brittleness of glassy materials.
Glassy materials have a non-crystalline, amorphous structure that make them inherently strong but invariably brittle. Whereas the crystalline structure of metals can provide microstructural obstacles (inclusions, grain boundaries, etc.,) that inhibit cracks from propagating, there’s nothing in the amorphous structure of a glass to stop crack propagation. The problem is especially acute in metallic glasses, where single shear bands can form and extend throughout the material leading to catastrophic failures at vanishingly small strains.
“Because of the high bulk-to-shear modulus ratio of palladium-containing material, the energy needed to form shear bands is much lower than the energy required to turn these shear bands into cracks,” Ritchie says. “The result is that glass undergoes extensive plasticity in response to stress, allowing it to bend rather than crack.”
Ritchie, who holds joint appointments with Berkeley Lab’s Materials Sciences Division and the University of California (UC) Berkeley’s Materials Science and Engineering Department, is one of the co-authors of a paper describing this research published in the journal Nature Materials under the title “A Damage-Tolerant Glass.”
Co-authoring the Nature Materials paper were Marios Demetriou (who actually made the new glass), Maximilien Launey, Glenn Garrett, Joseph Schramm, Douglas Hofmann and William Johnson of Caltech, one of the pioneers in the field of metallic glass fabrication.
Tuesday, April 26, 2011
SALT LAKE CITY, January 10, 2011 – Inexpensive igloo-shaped, pollution-eating devices nicknamed "Poo-Gloos" can clean up sewage just as effectively as multimillion-dollar treatment facilities for towns outgrowing their waste-treatment lagoons, according to a new study.
"The results of this study show that it is possible to save communities with existing lagoon systems hundreds of thousands, if not millions of dollars, by retrofitting their existing wastewater treatment facilities with Poo-Gloos," says Fred Jaeger, chief executive officer of Wastewater Compliance Systems, Inc., which sells the Poo-Gloo under the name Bio-Dome.
Kraig Johnson, chief technology officer for Wastewater Compliance Systems, will present the study Jan. 13 in Miami during the Water Environment Federation's Impaired Water Symposium. It also will be published in the symposium program.
Wastewater treatment in small, rural communities is an important and challenging engineering task. Proper treatment includes disinfection and the removal of unwanted pollutants. Most rural communities rely on wastewater lagoons as their primary method of treatment because they are simple and inexpensive to operate. Lagoons are large ponds in which sewage is held for a month to a year so that solids settle and sunlight, bacteria, wind and other natural processes clean the water, sometimes with the help of aeration.
But as communities grow and-or pollution discharge requirements become more stringent, typical wastewater lagoons no longer can provide adequate treatment. Until now, the only alternative for these communities was to replace lagoons with mechanical treatment plants, which are expensive to build and operate. Mechanical plants treat water in 30 days or less, using moving parts to mix and aerate the sewage, speeding the cleanup. They require electricity, manpower and sometimes chemicals.
Johnson and his research team developed the Poo-Gloo when he worked as a research assistant professor of civil and environmental engineering at the University of Utah. The Poo-Gloo was designed to address the problem faced by communities outgrowing their sewage lagoons. The device provides a large surface area on which bacteria can grow, providing the microbes with air and a dark environment so they consume wastewater pollutants continuously with minimal competition from algae.
The new study outlines results of a pilot project conducted in 2009 at Salt Lake City's Central Valley Water Reclamation Facility. Wastewater Compliance Systems obtained an exclusive license from the University of Utah to commercialize Poo-Gloos, so the devices now have been deployed in six states in either full-scale installations or pilot demonstrations. Every installation showed Poo-Gloos provide treatment that meets pollution-control requirements.
Lynn Forsberg, public works director for Elko County, Nev., recently started using Poo-Gloos in a county sewage treatment lagoon system in Jackpot, Nev., after a successful pilot test. "Our alternative was to go with a full-blown [mechanical] treatment plant that would cost about four times as much and be much more labor intensive," he says.
A remote-controlled stereo vision system now under development could revolutionize the science of watching how, where and when waves tear up coastlines, say researchers.
Storm swells that pound at coastlines -- thrilling surfers and worrying coastal engineers -- have always been hard to monitor. Wave-measuring buoys don't work well in the surf zone. Like other methods, they only provide data for one small point of surf rather than the beach-wide, broader-scale surf event.
Radar systems, for their part, provide nice wave speed information -- like a police officer's radar gun -- but are not very good at measuring wave heights.
By linking two visible-light camera together, however, and processing the images in a way similar to how the human brain does with the vision of two eyes, loads more wave data can be collected without even getting a toe wet. The potential applications of the technique are growing more important as climate change is growing larger surf that threatens more coastlines worldwide.
"It's like two eyes," explained researcher David Hill of Oregon State University. "It doesn't just see the waves and see them moving, but how high they are."
Hill worked with Dutch researchers on a stereo vision system that is beginning to yield specific wave height information for a swath of surf that is more on the scale of a recreational beach. Their research results will be published in the March 2011 issue of the journal Coastal Engineering.
"As you get closer to shore, there's a lot more variability" caused by shoaling waters refractions of waves and other shoreline effects, Hill explained to Discovery News. There have been other attempts to use stereo vision to measure waves, he said, but not on a realistic and useful area of surf.
Their latest experiment involved two off-the-shelf digital cameras on a pier on the Dutch coast. The data was processed by an ordinary desktop computer.
HANGZHOU, CHINA - Gravel-laden barges glide past the willow-fringed banks of the Grand Canal, plying a trade route built 2,500 years ago to bring grain from China's fertile south to its rulers in the north.
Now the 1,125-mile passage is part of an even grander scheme: a $150 billion plan to bring water from the mighty Yangtze River to the parched north in what is the world's most expensive infrastructure project.
Increasingly, a group of rising economies, from Brazil to the United Arab Emirates, is building the showcase projects that once were mainly the pride of the United States, Western Europe and Japan. America's Hoover Dam made headlines in the 1930s; today, it is China's $25 billion Three Gorges Dam.
Just as railways and highways transformed the United States into an industrial superpower, the 21st-century building boom is laying the foundations for these rapidly growing economies to join the top leagues.
"Projects are getting bigger and bigger in the developing economies, not only to cater for demand but also in anticipation of future growth," said Wilfred Lau, director at the engineering and design consultancy Ove Arup & Partners in Hong Kong.
Half of the 30 most expensive projects globally are in China, Brazil, the Middle East and other parts of the developing world, according to a list compiled by the Associated Press. A dozen are in wealthy countries, and three others are energy pipelines that will link Western Europe with Russia and Turkey. The data come from governments and companies involved in the various projects, and from AP archives.
Not all these projects will necessarily be completed, but cancellations would seem at least as likely among the cash-strapped governments of the West and Japan as anywhere else.
TULSA, Oklahoma – The salt and sand trucks are out ready to treat bridges when the snow and ice comes, but what if bridges had something inside them to prevent them from freezing?
There is technology that does that.
Scientists have tried hot water and electric heat to make bridges less likely to freeze. Oklahoma State proved several years ago there is a system that works.
Jeff Spitler and his colleagues at Oklahoma State University built a geothermal "smart bridge" back in 2001. It melts snow and ice with hot water that's pumped through the bridge in the summer.
"You know how hot concrete gets in Oklahoma gets in the summer, I don't know if you can really fry an egg on it, but it seems like it. And we actually circulate fluid in these tubes in the bridge deck down into the ground," Spitler said.
The water is stored deep underground and pumped back out in the winter.
"We actually store it from the summer to winter," Spitler said.
Before the bridge can ice over, the geothermal system warms the surface just enough.
The problem is the cost of installation and maintenance. The upside is it extends the life of a bridge, while keeping it clear of snow in bad weather.
The Oklahoma Department of Transportation has not pursued the technology. Cost is the problem, both for fixing the bridges we have and for adding any new technology along the way.
Many factors are involved in how a river behaves and the creation of a river delta. Firstly, of course, there is the river itself. What kind of material does it transport to the delta? Does this material consist of small particles (clay) or larger particles (sand)? But other important factors include the extent of the tidal differences at the coast and the height of the waves whipped up by the wind. In this study, researchers at TU Delft are working together with Deltares and making use of the institute's computer models (Delft3D software). These models already take a large number of variables into account. Geleynse et al. have now supplemented them with information on the subsoil. It transpires that this variable also exerts a significant influence on how the river behaves and the closely related process of delta formation
These are the results of the model for the sedimentary composition of the subsoil at the horizontal white lines in Figure 2. The initial situation (soil elevation) is indicated by the dotted black lines. The figure on the left represents a situation in which only sand is present in the subsoil at the beginning of the model simulation. The clay visible in this delta was therefore carried along by the upper-current river. The figure on the right shows a situation in which a great deal of clay is present in the initial subsoil, in addition to sand. The figure in the middle shows a situation in which there is more of a volumetric balance between sand and clay in the initial subsoil. The blue line indicates the calculated water surface. The figure presents the information as if the viewer is looking downstream. Credit: Geleynse et al
Room for the River
The extra dimension that Geleynse et al. have added to the model is important to delta management, among other things. If – as the Delta Commission recommends – we should be creating "Room for the River", it is important to know what a river will do with that space. Nathanaël Geleynse explains: "Existing data do not enable us to give ready-made answers to specific management questions ... nature is not so easily tamed ... but they do offer plausible explanations for the patterns and shapes we see on the surface. The flow system carries the signature of the subsoil, something we were relatively unaware of until now. Our model provides ample scope for further development and for studying various scenarios in the current structure."
Mapped results from the model for various types of sediment in the subsoil and for various types of water movement, for a given point in time. In all cases the initial situation (elevation) is as presented in the river-coast system schematic. Credit: Geleynse et al
River management is all about short-term and possible future scenarios. But the model developed by Geleynse et al. also offers greater insight into how a river/delta has developed over thousands of years. What might the subsoil have looked like and – a key factor for the oil industry – where might you expect to find oil reserves and what might their geometrical characteristics be? In combination with data from a limited number of core samples and other local measurements, the model can give a more detailed picture of the area in question than was possible until now.
Lessons from Afghanistan: Fulbright Scholar at UB, an Afghan Native, Seeks to Popularize Earthquake-Engineering Technology He Learned While Building
The area along the Pakistan-Afghanistan border that underwent a magnitude 7.2 earthquake last week is one that University at Buffalo graduate student and Fulbright scholar Mustafa Mashal knows well.
Before arriving at UB in 2009, Mashal spent several years working for a prime contractor of the U.S. Army Corps of Engineers, designing and constructing military bases in the region, home to numerous insurgent groups, for the Afghan National Army and Border Police.
Fortunately, because of the area's sparse population and the temblor's low intensity, it caused minimal damage or disruption in Afghanistan, but it destroyed more than 200 homes near the epicenter in Pakistan.
Mashal says the region's seismicity is well known.
"Afghanistan has a much more severe risk of earthquakes than California does," he says. "Every other month, we have something on the order of a magnitude of more than 7.0 in the Hindu Kush region in northeastern Afghanistan."
The intense and frequent seismicity of this part of the world, especially the 2005 Pakistani earthquake, which killed 80,000 people, helped inspire Mashal to study earthquake engineering to find ways to make homes and buildings safer.
Ultimately, he decided to come to UB to study with renowned professors who conduct research in UB's MCEER (formerly the Multidisciplinary Center for Earthquake Engineering Research).
Mashal is taking full advantage of the structural engineering curriculum and top-notch research facilities in the UB Department of Civil, Structural and Environmental Engineering in the School of Engineering and Applied Sciences.
He also is sharing with classmates and instructors some of the novel things he learned while on the job in various remote Afghanistan regions, which have recently attracted the attention of his professors.
Last semester, one of his class assignments was to pick a building in Buffalo and design a way to retrofit it so it would better stand up to an earthquake. Mashal convinced his team to develop the retrofit with 3-D panels, the technology he learned to use in Afghanistan to quickly construct buildings for military bases.
The key advantage of 3-D panels is that they are strong but lightweight, Mashal says. Not only can they stand up to significant seismic forces, they can resist hurricane force winds as well as blasts.
The 3-D panels consist of an expanded polystyrene core sandwiched between two cover mesh sheets, which are welded together by diagonal connectors that go through the polystyrene core. Two layers of a strong concrete are then applied to both sides of the panel.
Jorhat, Jan. 27: A professor of Kyushu University at Fukuoka in Japan, hailing from Jorhat, has come up with two novel earthquake resistant techniques advocating the use of recycled tyres with sand and cement to minimise impact of severe earthquakes on buildings.
Hemanta Hazarika, an alumnus of JB College Jorhat, is a professor of the geotechnical engineering group in the department of civil and structural engineering of the university that is completing its centenary this year.
Hazarika, who was in his hometown for a few days, spoke exclusively to The Telegraph about the two research projects of which he is the team leader. Hailing from a very high seismic zone (Northeast) and Assam witnessing a major earthquake in 1950 that had caused largescale loss of human lives and property, the professor hopes the techniques could be of use in the region.
Hazarika, also an alumnus of IIT Chennai, had been in Japan for the last 19 years working with construction companies and research organisations before taking up teaching about eight years back. He said being in Japan, a country known for frequent and big earthquakes, his interest had been kindled on research work to find out ways to reduce the damage from earthquakes.
Speaking about one of the techniques evolved by the research group under him that took about seven years, Hazarika said a cushion, made of recycled tyre chips (very small pieces cut out from tyres) which is mixed with sand, is attached to both sides of a wall of a building. The professor said a cushion made from recycled-tyre having elasticity, being lightweight and with high vibration absorbing capacity and long durability, could prevent a building from collapsing when attached to both sides of the walls. He said cement, too, along with sand, could be mixed with the tyre chips for making the cushion a bit stronger. Tests had shown “good results”. The project has completed application trials and he has got a patent in Japan for it. Hazarika said the technique was expected to be released soon for commercial use with the proposal being submitted to the Japanese government and also to private construction companies.
Another technique being developed by the group under Hazarika over the last three years is by laying out layers of recycled-tyre chips mixed with sand beneath the foundation of a building for soil improvement is in advanced stage of research. The professor said the technique was aimed at preventing artificial floods and largescale damage of buildings during a big earthquake in a sandy region having water table on top level of soil; because of a phenomenon called liquefaction, the soil turns into water with high water pressure.
CareerStructure's Salary Benchmarker Tool Enables Jobseekers and Recruiters to Determine Competitive Remuneration and Benefits at a Glance
CareerStructure.com has launched an interactive Salary Benchmarker tool based on a comprehensive survey of professionals occupying jobs in construction and the built environment.
The CareerStructure.com salary survey examined salaries and rewards across the industry and the results displayed in the tool, enables jobseekers and recruiters to determine competitive remuneration and benefits at a glance.
Information on specific job types can be filtered by region, sector and level of experience. At each stage the number of respondents who match the criteria is displayed, along with their average salary, annual bonus and the benefits they currently receive. Of particular interest to recruiters is the ‘desired benefits’ column, which shows what the respondents would most like in a new job, and the ‘important factors’ column which shows what factors the respondents consider most important to job satisfaction.
The tool covers 20 different job types, allowing users to make comparisons between the salary and benefits of each role. However, with 11 regions from the UK and 8 international regions also included in the survey, comparisons can be made between all criteria to ascertain what salary and benefits the respondents expect to be receiving, and what they are actually experiencing.
Joint developers Hopes Homes (Scotland) and Zero C Holdings have appointed JMP to the groundbreaking Knockroon development on the Dumfries Estate near Cumnock where planning permission for the first phase has now been granted by East Ayrshire Council.
In the first phase will be 87 homes, 12 work units, four commercial buildings and a local shop. The 28.18ha development, with its open spaces and network of footpaths, will eventually accommodate around 600 homes, together with shops, workplaces and other community facilities on 19.67ha of the site.
JMP is carrying out detailed design of road and drainage infrastructure for a “walkable neighbourhood” development in Ayrshire being undertaken by The Prince of Wales.
The pioneering project is being taken forward by a subsidiary of the Prince’s Charities Foundation, working with Hope Homes and Zero C, and will be a leading example of sustainable development, as well as acting as a catalyst for The Prince’s vision for heritage-led regeneration in the area
The Masterplan for the site was drawn up by the Prince’s Foundation for the Built Environment after extensive community consultation and follows the principles used by The Prince of Wales for his successful development at Poundbury in Dorset.
University House Central Florida will offer state of the art student-oriented amenities including a large pool and patio deck, fitness center, sand volleyball, basketball court, putting green, clubhouse with multi-media lounge and parking garage.
Winter Park Construction (WPC) has broken ground on University House Central Florida (UCF), an off-campus student housing project located one half-mile from Orlando's University of Central Florida campus. The one-, two-, three- and four-bedroom apartments range in size from 500 –1,600 square feet. All units will be fully furnished.
With more than 20,000 units constructed throughout the country, WPC has a solid reputation in student housing construction. Prior projects include: Hawks Landing, Tampa; Northgate Lakes, Oviedo; and Countryside at The University and University Terrace, both in Gainesville.
The development/management company for University House Central Florida is Dallas-based Inland American Communities. The project architect is Humphreys & Partners.
The 416-unit project is expected to be completed in August 2012 and will create 400 jobs.
Monday, April 25, 2011
CORVALLIS, Ore. – Engineers have created a new type of “stereo vision” to use in studying ocean waves as they pound against the shore, providing a better way to understand and monitor this violent, ever-changing environment.
The approach, which uses two video cameras to feed data into an advanced computer system, can observe large areas of ocean waves in real time and help explain what they are doing and why, scientists say.
The system may be of particular value as climate change and rising sea levels pose additional challenges to vulnerable shorelines around the world, threatened by coastal erosion. The technology should be comparatively simple and inexpensive to implement.
“An ocean wave crashing on shore is actually the end of a long story that usually begins thousands of miles away, formed by wind and storms,” said David Hill, an associate professor of coastal and ocean engineering at Oregon State University. “We’re trying to achieve with cameras and a computer what human eyes and the brain do automatically – see the way that near-shore waves grow, change direction and collapse as they move over a seafloor that changes depth constantly.”
This is the first attempt to use stereo optical imaging in a marine field setting on such a large scale, Hill said, and offers the potential to provide a constant and scientifically accurate understanding of what is going on in the surf zone. It’s also a form of remote sensing that doesn’t require placement of instruments in the pounding surf environment.
Applications could range from analyzing wave impacts to locating shoreline structures, building ocean structures, assisting the shipping industry, improving boating safety, reducing property damage or, literally, providing some great detail to surfers about when the “surf’s up.”
Only in recent years, Hill said, have extraordinary advances in computer science made it possible to incorporate and make sense out of what a dynamic marine environment is doing at the moment it happens.
“A wave is actually a pretty difficult thing for a computer to see and understand,” Hill said. “Some things like speed are fairly easy to measure, but subtle changes in height, shape and motion as the waves interact with a changing ocean bottom, wind and sediments are much more difficult.”
Researchers at OSU and the Technical University of Delft in The Netherlands made important recent advances toward this goal, which were reported in Coastal Engineering, a professional journal.
Other studies at OSU have documented that ocean wave heights and coastal erosion in the Pacific Northwest are increasing in recent decades, adding to the need for a better understanding of those waves when they hit shore.
One study just last year concluded that the highest offshore waves may be as much as 46 feet, up from estimates of only 33 feet that were made as recently as 1996, and a 40 percent increase.
Designing skyscrapers to withstand earthquakes is getting easier thanks to a team of researchers and practitioners organized by the Pacific Earthquake Engineering Research Center (PEER) at UC Berkeley. A new guide developed by PEER's Tall Building Initiative, led by UC Berkeley structural engineering professor Jack Moehle, has standardized the design and review process for evaluating the seismic safety of buildings over 140 feet tall.
The PEER Center is pleased to announce the release of the “Guidelines for Performance-Based Seismic Design of Tall Buildings” that was developed by PEER’s Tall Buildings Initiative.
The Guidelines present a recommended alternative to the prescriptive procedures for seismic design of buildings contained in standards such as ASCE 7 and the International Building Code (IBC). They are intended primarily for use by structural engineers and building officials engaged in the seismic design and review of individual tall buildings.
Properly executed, the Guidelines are intended to result in buildings that are capable of achieving the seismic performance objectives for Occupancy Category II buildings intended by ASCE 7. Alternatively, individual users may adapt and modify these Guidelines to serve as the basis for designs intended to achieve higher seismic performance objectives.
The Guidelines were developed considering the seismic response characteristics of tall buildings, including relatively long fundamental vibration period, significant mass participation and lateral response in higher modes of vibration, and a relatively slender profile. Although the underlying principles are generally applicable, the Guidelines were developed considering seismic hazard typical in the Western United States.
Newswise — A researcher at Missouri University of Science and Technology is leading a study to increase the amount of fly ash used in concrete. If successful, the effort could divert millions of tons of the waste product away from ponds and landfills and reduce CO2 emissions.
Currently the nation’s power plants generate about 130 million tons of fly ash and bottom ash during the coal combustion process. Fly ash - the fine particles that rise with flue gases during combustion - are captured through filtration to reduce air pollution and are often stored at coal power plants or placed in landfills.
Adding fly ash to concrete isn’t a new concept. For more than 70 years, the waste product has been a component of concrete used to build the nation’s bridges, roads, dams and overall infrastructure. The material increases concrete’s durability, extending the service life of these structures. About 43 percent of the material is recycled as components of wallboard or concrete.
“Traditional specifications limit the amount of fly ash to 35 or 40 percent cement replacement,” says Jeffery Volz, assistant professor of civil, architectural and environmental engineering at Missouri S&T. “Recent studies have shown that higher cement replacement percentages – even up to 75 percent – can result in excellent concrete in terms of both strength and durability.”
Concrete typically has three key components: portland cement, water and aggregates like gravel and sand. During the manufacture of cement, limestone and other materials are heated to extreme temperatures, releasing tons of CO2 from both chemical reactions and the heating process. If fly ash could replace cement, it would not only reduce the amount of fly ash that ends up in ponds and landfills but CO2 emissions as well, says Volz.
High-volume fly ash is significantly more sustainable, but also can be unpredictable. The physical and chemical characteristics of the material can vary, which can change how it reacts to additives.
“A¬t all replacement rates, fly ash generally slows down the setting time and hardening rates of concrete at early ages, especially under cold weather conditions, and when less reactive fly ashes are used,” Volz says.
The disposal of fly ash isn’t without some controversy. In December 2008, 1 billion gallons of wet coal ash spilled when an earthen retaining wall of an ash pond gave way. Dozens of wells were contaminated with toxic materials, like arsenic and mercury. Soon after, the Environmental Protection Agency began reviewing regulation of the material. While the EPA supports adding fly ash to concrete or using it for soil stabilization, the agency is considering designating fly ash as a hazardous waste. The ruling would attach a stigma to the material despite solid evidence that once fly ash is added to concrete, the material is chemically altered and unable to leach the toxic materials over time.
Under the weight of record snows, roofs across the Northeast have been buckling this winter, raining debris on children skating in ice rinks, crushing cows and tractors in farmers’ barns and even flattening a garage full of antique cars. In December, nearly 18 inches of new heavy snow brought down the roof of the Metrodome in Minneapolis, forcing the Vikings to temporarily relocate to Detroit.
And it was not just American infrastructure that appeared to be under the weather, so to speak. In Brisbane, Australia, January storms ripped apart a riverside boardwalk — turning a concrete section 150 yards long into a waterborne torpedo that threatened downstream bridges. The wall of a Hungarian reservoir holding toxic red sludge crumbled in October after weeks of downpours, sending the waste into nearby villages. The litany of extreme weather events has often left local officials scrambling to respond to each new crisis, looking — by turns pathetic and heroic — like the little Dutch boy with his finger in the dike, trying to fend off nature’s monumental forces.
Global warming is most likely responsible, at least in part, for the rising frequency and severity of extreme weather events — like floods, storms and droughts — since warmer surface temperatures tend to produce more violent weather patterns, scientists say. And the damage these events have caused is a sign that the safety factors that engineers, architects and planners have previously built into structures are becoming inadequate for the changing climate.
Dikes, buildings and bridges are often built to withstand a “hundred-year storm” — an event so epic that there is a 1 percent chance it will happen in a given year. But what happens when 100-year storms are seen every 10 years, and 10-year storms become regular events? How many structures will reach their limits?
Engineers and insurers are already facing these questions. Munich Re, one of the world’s largest insurance companies, says climate-related events serious enough to cause property damage have risen significantly since 1980: extreme floods tripled and extreme windstorms nearly so. (The number of damaging earthquakes — which are not thought to be influenced by climate change — have remained stable.) Statistics show that the frequency of days with heavy precipitation is up in South America, North America and parts of Europe
Your own perception that there are more storms and more flooding causing damage — that is extremely well documented,” said Peter Hoeppe, a meteorologist who is the head of Munich Re’s Corporate Climate Center. “There is definitely a plausible link to climate change.”
For insurers, the challenge has been how to insure structures against the vicissitudes of increasingly extreme and severe weather. For engineers, new weather raises difficult questions about what kinds of safety factors should be built into designs and whether old structures need retrofitting or reinfo
In 2008, the Virginia Department of Transportation began work adding a fourth lane to the six-mile stretch of Interstate 95 between the Springfield interchange and the exit for Virginia State Road 123.
This is likely of very little consequence to you, but it was a life-changing moment for me: I live not far from State Road 123. And my daily commute along that stretch of I-95 had been slowly killing everything that was once good inside me.
As it stood then, that section of I-95 had only three lanes in either direction, carrying 212,000 vehicles per day. That's an average of 1,472 cars per lane, per hour. During peak commute times, the flow was much, much greater.
Under optimum conditions, a lane of freeway can handle 2,000 vehicles per hour. Any flow above that rate disrupts the network. The result, at least on my little stretch of interstate, is that between 6 and 9 a.m., and then 3 and 7 p.m., traffic grinds to a halt, accelerates to 25 mph, and then crashes back to zero mph. Over and over again. The civil engineering term for this is "congestion." The theological term is "purgatory."
So I was in a state of spiritual bliss when the commonwealth of Virginia decided to spend $123 million to add an extra lane in each direction. And after three years of construction, the new lanes are set to open soon.
The only problem is that people who take traffic seriously -- the pointy-heads who staff university engineering programs and government planning bureaucracies -- keep telling me that the extra lanes aren't going to help one bit. After a year or so, they say, I'll be mired in congestion all over again.
Like many sects, traffic planners have their dogmata. One of their doctrines is that adding capacity to highways is futile because it merely creates more traffic. This phenomenon is called "induced demand," or, more colloquially, "build it, and they will come."
The theory is simple: Traffic systems that suffer from congestion have latent demand -- that is, a universe of drivers who would use the freeway, but don't, because of the traffic.
When you add extra capacity to the highway, there may be an initial decrease in congestion. But then the latent demand begins to flow into the system and it quickly fills the road back up to the previous traffic level.
Congestion" is not a problem, but rather an equilibrium point to which traffic systems inevitably tend. To use a science-ish metaphor, in this worldview traffic is not a liquid, which can be funneled; it is a gas, which expands to fill any constraint.
The idea of induced demand comes up a lot in modern transit discussions. Whenever a government entity wants to add highway capacity, the induced-demand crowd tut-tuts about it being wasteful, or even harmful.
A pioneering technology used in India to remove arsenic from groundwater without using chemicals is being used to create safer drinking water in the United States.
The technology-Subterranean Arsenic Removal-has been developed by scientists at Queen's University Belfast.
The team of European and Indian engineers, led by Bhaskar Sen Gupta in Queen's University School of Planning, Architecture and Civil Engineering developed the technology based on the principle of oxidation and filtration processes, is already in use in six plants in West Bengal.
And the technology has now been successfully tested in the United States, in a rural community outside Bellingham, in Northwest Washington State, where high levels of arsenic in the water had previously caused challenges for local residents.
Jeremy Robinson, a member of the Washington State installation team, said, "We first read about the SAR technology on Wikipedia. Initially, it seemed too good to be true. Arsenic is a significant problem for many of the wells in our area. None of the conventional approaches for arsenic treatment have worked well for us. But, once we recognised the advantages and elegance of the SAR approach, we started preparing to test it here."
Gupta, who visited Washington State to oversee the installation, said: "I'm delighted that the Washington State plant testing has gone to plan. The key aspects of this life-changing technology are its affordability and simplicity of installation and operation."
While most people know that earthquakes can cause buildings, bridges, and other structures to crack, distort, and even fail, mechanical, electrical, and plumbing system failures often get overlooked. People fear earthquakes because they can be injured from falling structural elements like columns or beams or architectural components like brick facades or windows. But what about the lights overhead, the rooftop units, pipes, or storage tanks? These nonstructural components can injure people when their supports and attachments fail.
The number-one goal of a building code is to protect people. The building code that governs the majority of the United States is the International Building Code (IBC), which is published by the International Code Council (ICC). IBC Chapter 16, as well as Chapters 11-13 and 15-23 of American Society of Civil Engineers (ASCE) 7—Minimum Design Loads for Buildings and Other Structures, address seismic design. Although the main purpose of the IBC is to safeguard against major structural failures and loss of life, this does not imply that damage should be limited or the function of the building be maintained. Buildings and other structures that support the mechanical, electrical, or plumbing (MEP) components are divided into occupancy categories (IBC Table 1604.5), which are used to determine the level of seismic loads and detailing required.
Essential facilities such as hospitals, police and fire stations, power plants, or water treatment facilities are examples of higher level occupancy categories (III or IV), which can require a higher level of analysis, design, and detailing than a lower occupancy category building in the same region of the country. Essential facilities like these require immediate occupancy or continued use after an earthquake, which can require continued function of MEP components after an earthquake as well. Life safety systems such as fire sprinkler systems and essential electrical systems require seismic bracing to stay in service.
To determine the level of analysis, design, and detailing that will be required for the structural, architectural, and MEP components, the structural engineer will need to calculate the seismic design category. This calculation takes into account the location of the building near a fault, the occupancy category of the building (as previously mentioned), and the soil characteristics of the site. Seismic design categories A, B, or C are deemed low to moderate, whereas categories D, E, or F are deemed high to severe. Structures located in California, for example, will typically fall into a high to severe category, while structures located in Wisconsin will fall into low to moderate. Once the seismic design category has been determined, the analysis and design begins. The design of MEP supports and anchorages is covered in ASCE sections 13.3, 13.4, and 13.6.
Below is a partial list of some important items that should be considered and shown by MEP engineers on the construction documents. The list is culled from three very useful documents produced by the Federal Emergency Management Agency (FEMA)—412, 413, 414—as well as from the authors’ personal experience. The FEMA documents are only guides; in all instances local building codes, such as the IBC, control the design.