Newswise — Each year, coal-burning power plants, steel factories and similar facilities in the United States produce more than 125 million tons of waste, much of it fly ash and bottom ash left over from combustion. Mulalo Doyoyo has plans for that material.
An assistant professor in Georgia Tech's School of Civil and Environmental Engineering, Doyoyo has developed a new structural material based on these leftovers from coal burning. Known as Cenocellâ„¢, the material offers attributes that include high strength and light weight " without the use of cement, an essential ingredient of conventional concrete.
With broad potential applications and advantages such as good insulating properties and fire resistance, the "green" material could replace concrete, wood and other materials in a broad range of applications in construction, transportation and even aerospace.
"Dealing with the ash left over from burning coal is a problem all over the world," said Doyoyo. "By using it for real applications, our process can make the ash a useful commodity instead of a waste product. It could also create new industry and new jobs in parts of the world that need them badly."
Fly ash is composed of small particles removed from combustion gases by pollution control systems. Most of it must now be disposed of as a waste product, though certain types of fly ash can be used to replace a portion of the cement used in conventional concrete.
Cenocell, produced from either fly ash or bottom ash in a reaction with organic chemicals, requires none of the cement or aggregate " sand and rock " used in concrete. And unlike concrete, it emerges from curing ovens in final form and does not require a lengthy period to reach full strength.
Monday, February 28, 2011
Newswise — Each year, coal-burning power plants, steel factories and similar facilities in the United States produce more than 125 million tons of waste, much of it fly ash and bottom ash left over from combustion. Mulalo Doyoyo has plans for that material.
New York, NY (November 2008)—It's been more than a year since the collapse of the I-35W bridge in Minneapolis. And now, the final report put forward by the National Transportation Safety Board has concluded from its investigation: (1) the steel gusset plates originally designed in the mid-1960s to reinforce the bridge's joints were half an inch too thin; (2) the probable causes for the collapse were additional modifications to the original design, which added substantial weight to the bridge, and the weight added by construction materials placed on the bridge by a contractor just prior to the collapse. That's it. And if you're thinking Surely, there was more to the collapse than that, construction expert Barry B. LePatner says you are right. And by ignoring the other (extremely critical) factors, the NTSB is perpetuating a problem that puts millions of Americans in danger every day.
"The NTSB is severely neglecting its duty to protect Americans," says LePatner, coauthor of Structural & Foundation Failures (McGraw-Hill, 1982, coauthored with Sidney M. Johnson, P.E.) and author of Broken Buildings, Busted Budgets: How to Fix America's Trillion-Dollar Construction Industry (The University of Chicago Press, October 2007, ISBN-13: 978-0-226-47267-6, ISBN-10: 0-226-47267-1, $25.00). "By placing the sole blame for the bridge collapse on the gusset plates and the added weight factor, the Board has ignored the inefficiency and irresponsibility among the government agencies responsible for the bridge, which also contributed to the disaster."
At the heart of many of these problems is the Minnesota Department of Transportation, which (and here's a scary thought!) has long been considered one of the better state transportation departments in the country. Basically, MnDOT failed to protect the public from a preventable disaster that was long in the making. And the problems faced by MnDOT are far from isolated. DOTs everywhere are struggling to keep the highways and byways that connect this nation in working order.
We must put these struggles in perspective: There are 12,000 bridges in our country whose designs are similar to the I-35W Bridge. Furthermore, according to statistics from a 2007 U.S. Department of Transportation/Research and Innovative Technology Administration report, there are over 72,000 bridges that are labeled "structurally deficient" and over 81,000 bridges identified as "functionally obsolete." Every one of these bridges needs detailed inspections to ensure their safety
The preliminary results of the yearlong study by civil engineering researchers at the University of Minnesota were released last night to a crowd of about 400 people attending the university's Institute of Technology public lecture "Investing in Infrastructure." The university's findings are consistent with the National Transportation Safety Board's final report summary and the report prepared by Wiss, Janney, Elstner Associates (consultants retained by the Minnesota Department of Transportation).
Highlights of the U of M academic study revealed the following:
Some of the gusset plates in the I-35W bridge were not designed to withstand the design loads with an acceptable safety factor.
Construction on the bridge in the 1970s and 1990s, including the addition of thicker road beds and guard rails, added significant weight on the bridge. The resulting forces stressed these gusset plates beyond acceptable limits.
Additional weight from the construction on Aug. 1, 2007 produced substantial additional forces on the already compromised critical gusset plates. The construction material and equipment most likely initiated the collapse.
Temperature changes on the day of the collapse, coupled with partially frozen bridge bearings, may have also introduced additional stresses to the gusset plates.
"The gusset plates at the time of collapse were in a state of instability. In essence the demand on them was equal to their capacity, and they simply gave way," said civil engineering professor and department head Roberto Ballarini.
Researchers involved in the study include civil engineering faculty Roberto Ballarini, Taichiro Okazaki, Ted Galambos and Arturo Schultz.
The researchers conducted their study of the gusset plates in two stages. In the first stage, they created two-dimensional and three-dimensional computer models representing the whole bridge. The second stage consisted of applying the forces calculated in these models to a detailed computer model of the node of the bridge that involved the suspected gusset plate.
"Our computer simulation shows a pattern of very high stresses within the gusset plate that are consistent with the locations and directions of the tears observed in photos of the fractured gussets," Ballarini said.
Minneapolis, Minn. — Roberto Ballarini was next to the collapsed I-35W bridge in Minneapolis the morning after. He stood among people from the FBI, Homeland Security and transportation officials as an invited expert. Even then, Ballarini says, there was intense interest in what role weakened gusset plates may have played in the collapse of the span. Now, more than a year later, Ballarini says he does not disagree with the National Transportation Safety Board's official finding that underdesigned gusset plates were the root cause of the disaster.
"We also identified that as the possible culprit in this tragic event," he says.
The, 'we,' Ballarini refers to are a couple of other department of civil engineering faculty and some students at the U. They'll present pictures and a computer simulation of the collapse.
Their exploration, Ballarini says, is an academic exercise for the benefit of students and not an investigation meant to compete with the NTSB.
Ballarini, ever the diplomat, describes the new 35W bridge as, "unassumingly elegant," and then in an aside says he would have added some touches to make it a bit more aesthetically pleasing.
Ballarini singles out what no one should miss; a typical completion time for a project the size of the new bridge is three years but it was completed in 11 months.
"That's also a testament to the industry in the United States that structure like that could be built so fast," he says.
The lesson from the 35W bridge building experience is if America decides to get to work repairing and replacing our infrastructure the job can be done fast and well.
And, Ballarini says, there's no shortage of work.
Italian by birth, Brooklyn by upbringing, Ballarini is not shy about laying it on the line. The country's crumbling infrastructure is a national security issue.
The National Transportation Safety Board (NTSB) Nov. 14 released its report on the August 2007 I-35W bridge collapse in Minneapolis. The report cited that the probable cause was the inadequate load capacity, due to Sverdrup & Parcel and Associates Inc.’s design error of the gusset plates at the U10 nodes, which failed under a combination of 1) substantial increases in the weight of the bridge, which resulted from previous modifications, and 2) the traffic and concentrated construction loads on the bridge on the day of the accident.
Two contributing factors to the error were the company’s lack of quality control procedures to ensure that the appropriate main truss gusset plate calculations were performed for the bridge, and inadequate design review by federal and state transportation officials, including inadequate attention paid to gusset plates during inspections for conditions of distortion, such as bowing, and of excluding gusset plates in load rating analysis.
During its investigation, the NTSB learned that 24 under-designed gusset plates escaped discovery in the original review process and were included in the design and construction of the bridge. The plates were about half the thickness of properly sized gusset plates.
On Aug. 1, the day of the collapse, roadwork was under way on the bridge. In the early afternoon, construction equipment and construction aggregates were delivered and positioned in the two closed inside southbound lanes. The equipment and aggregates were staged for a concrete pour of the southbound lanes that was to be performed about 7 p.m. and positioned toward the south end of the center section of the deck truss portion of the bridge near node U10 and were in place around 2:30 p.m.
Later that evening, a lateral instability at the upper end of the Li/U10W diagonal member led to the failure of the U10 node gusset plates. Because the deck truss portion was considered non-load-path-redundant, the total collapse of the deck truss was unavoidable once the gusset plates failed.
Proposals to build a replacement for Heathrow in the Thames estuary have taken significant steps forward with Boris Johnson, the mayor of London, preparing to appoint the civil engineer behind Hong Kong’s giant island airport to examine the viability of the project.
The move comes as senior MPs have set up a cross-party group to lobby the government to investigate the idea.
Douglas Oakervee, the engineer who also chairs the Crossrail project for an east-west rail link in London, will tomorrow discuss with Johnson’s officials the terms of his involvement in a feasibility study.
Oakervee was the lead engineer in the construction of the £12 billion Hong Kong international airport, which was opened on mainly reclaimed land in 1998. The Thames estuary idea being drawn up by Johnson’s officials is loosely based on Hong Kong.
Pressure to replace Heathrow is growing as the government prepares to announce its decision on whether to build a third runway at the airport in the face of mounting environmental protests and rebellion from some cabinet ministers and local Labour MPs
Plans to build a replacement for Heathrow Airport off the coast of Sheppey have taken a step forward - despite widespread opposition, Yourswale reports.
London Mayor Boris Johnson is preparing to appoint the civil engineer behind Hong Kong’s £12 billion island airport to work on a similar proposal for the Thames Estuary.
The move comes as some senior MPs have set up a cross-party group to lobby the Government to investigate the idea.
This is despite the plan being opposed by both Sittingbourne and Sheppey MP Derek Wyatt and his rival Conservative parliamentary candidate Gordon Henderson.
Mr Henderson this week branded the plan "a dead duck", while Mr Wyatt said it was merely "political posturing".
The British Air Transport Association, which represents the UKs airlines, is also opposed to the idea and branded it a "non-starter".
Douglas Oakervee, the engineer who also chairs the Crossrail project for an east-west rail link in London, has discussed with the mayor’s officials the terms of his involvement in a feasibility study for the so-called "Boris Island".
The £120m plant, which supplies 700,000 consumers in Glasgow, was among the largest engineering feats undertaken by the Scottish water industry.
The facility replaces Victorian water works opened in 1859.
The Saltire Society said the project was an example of civil engineering's greatest contributions to society - the provision of clean safe drinking water.
Other projects across Scotland were also recognised by the award's panel which handed out commendations to the Dundee gas works land remediation scheme and the Clydebank Swan project.
Engineers involved in post tensioning work for the Clunie dam in Perthshire, the Melrose Town Centre project and those behind plans to regenerate Waverley station in Edinburgh were also recognised.
At Loch Katrine in the Trossachs, two tunnels linking Mugdock and Craigmaddie reservoirs, treatment works and tanks were all covered over with turf to blend in with surrounding pasture land.
Water from Loch Katrine will be filtered and treated at Milngavie.
The huge project, which officially opened earlier this year, follows a cryptosporidium contamination emergency in 2002 in which 160,000 people were told to boil their water.
Bullet trains used to be a luxury only found in foreign metropolises, but if voters approve a statewide ballot measure in November, they may be able to shoot across California in record time-as early as 2016.
If passed, Proposition 1A would provide nearly $10 billion in state bonds to begin construction on an ambitious high-speed rail system that would span from San Francisco to Los Angeles.
With a $55 ticket, riders could embark on a 188-minute journey, relieving highway and air traffic congestion, the California High Speed Rail Authority estimates.
Berkeley Mayor Tom Bates thought the rail plan would be a worthy investment for the people of Berkeley.
"It is expensive and it will need private capital," Bates said. "However, I think it's a good idea and we should definitely try it."
If approved by voters, proponents say the rail system could serve as a fast, low-cost way to travel for the 11,000 UC Berkeley students who have homes in the seven southernmost counties of California.
But others said the rail system could be a fiscal disaster.
According to a report by the Reason Foundation, which is anti-rail, the system would cost over $80 billion and would serve 23.4 million riders by 2030, as opposed to the 65.5 million estimate proposed by the authority.
While proponents say the system could reduce traffic, countries with similar systems in place have not seen a significant decrease in urban highway congestion, said Adib Kanafani, a UC Berkeley civil engineering professor.
Kanafani said that foreign rail systems often went far over budget during construction and only become financially self-sufficient after decades of operation.
"Other countries' rail projects often go over budget," he said. "Once you start digging you don't know what will happen. There are all sorts of uncertainties."
The rail system, to be stationed in San Francisco and potentially Oakland, will not pass through Berkeley.
Proponents said they hope to eventually extend service to Sacramento, San Diego, and the Inland Empire with multiple stops across the state.
HOUSTON — Officials from Galveston will ask Congress for about $2.2 billion in disaster relief this week to repair the battered island’s port, save a major research hospital from going under and rebuild the city’s infrastructure.
The estimate of the damage done when Hurricane Ike raked the island on Sept. 13 was breathtaking. With 57,000 residents, the amount officials are asking for works out to about $36,800 a resident.
In the wake of Hurricanes Katrina and Rita in 2005, the federal government has disbursed about $100 billion for things like housing reconstruction and infrastructure repairs along the entire Gulf Coast.
Mayor Lyda Ann Thomas of Galveston will appear before the Senate Ad Hoc Subcommittee on Disaster Recovery on Tuesday morning and will ask the federal government to foot the bill for $1.1 billion in damage to the city.
Mayor Bill White of Houston and Lt. Gov. David Dewhurst will also appear before the subcommittee, though neither intends to ask for a specific amount of money. Aides to both men said it was too early to assess the damage fully.
Galveston officials said the $1.1 billion would go to fix water, sewerage and drainage systems as well as traffic signals, roads and bridges. The city is also asking for money to build housing, give grants to small business owners and restore beaches, City Manager Steve LeBlanc said.
Friday, February 25, 2011
TEMPERANCE FLAT – Ron Jacobsma shifts his boat into idle, stopping to float right where he wants to see another dam rise across the San Joaquin River.
“We'll see it. I just don't know if I will see it in my lifetime,” mused Jacobsma, who oversees delivering water to nearly 1 million acres of farmland in the shadow of the Eastern Sierra.
That would suit Sean Lodge, whose family homesteaded near the dam site, just fine.
“There is a rich history that is important to preserve,” Lodge said via e-mail from his firefighting post in the Sierra National Forest. “There are not that many places in the state that have this history that is not lost already.”
Which course is set for San Joaquin River mile 274, better known as Temperance Flat, depends on whether Californians are ready to accept new dams to keep taps flowing even as growth and drought strain water supplies.
Voters may be offered the opportunity to decide the issue in November, but only if Gov. Arnold Schwarzenegger and state lawmakers can settle on the terms of a $9.3 billion water bond package in the coming days.
The bond proposal is packed with spending for popular clean-water, conservation and Sacramento delta restoration programs. But there also is a handful of unresolved issues, any one of which could draw away enough support to keep the measure from securing the necessary two-thirds vote of lawmakers and the governor's signature before it can be placed on the ballot.
Among those: a $700 million annual bill to repay the bond debt, power struggles over who would set spending priorities and suspicions that it lays the groundwork for a redrawn north-to-south aqueduct, an idea defeated when it went to voters as the Peripheral Canal in 1982.
And, of course, dams. More specifically, the proposed Sites Reservoir, located 16 miles in an isolated bowl west of the Sacramento River near Colusa, and Temperance Flat, not far from Fresno, where a dam would stretch the length of several football fields across the San Joaquin River.
A new task force, co-chaired by environmentalist Robert F. Kennedy, Jr, has been charged with crafting a plan to raise the money that will be needed, the Democratic governor said in a statement.
Paterson has previously urged Washington to reinvigorate the national economy with new public works projects.
The task force's other co-chair, Ross Pepe, is the executive director of the Construction Industry Council and Builders Contractors Association.
The construction industry as well as Wall Street banks and overseas developers eager to persuade state and city governments that public-private partnerships are appealing ways to fund infrastructure, also all have big stakes in the issue.
New York's waste water treatment plants will need more than $36 billion of repairs, while drinking water systems could need over $20 billion, Paterson estimated, blaming Washington for cutting federal aid by 70 percent over the past two decades.
This has delayed needed maintenance, causing hundreds of sewage and waste water treatment plants to deteriorate, and triggered violations of the Clean Water Act, Paterson said.
"This has been ignored for too long; water quality, public health and municipal finances are all at risk," the governor said.
New York's governor is not alone in pushing Washington for more dollars. Miami Mayor Manny Diaz, the newly-elected president of the U.S. Conference of Mayors, said in interview on Wednesday that the group will issue a report that shows the positive economic impact of water and sewer investments.
He's right, of course. We have traveled down four-lane highways that, were it not for the rice paddies and water buffalo, could be anywhere in the United States or Europe.
But while road engineering may be one of the most beneficial aspects of China's progress, it's not the most fascinating aspect about its sprint to first-world development status.
More compelling is the Chinese authorities' apparent obsession with building superlatives: the world's biggest dam, the world's biggest airport terminal, Asia's tallest skyscraper and the world's highest railway. You get the picture.
Symbols of political power or intellectual heft?
This obsession with creating and surmounting engineering challenges has not gone unnoticed. Critics of the central Chinese government dismiss these high-profile projects and massive infrastructure schemes as nothing more than political or nationalistic grandstanding, symbols that reinforce Beijing's power and authority.
Especially when it comes to the splashy landmarks built in the capital itself. "In the new Beijing, the state only protected sites that served to bolster its own self-justifying version of history," wrote Jasper Becker in a new book, "City of Heavenly Tranquillity."
The 80-storey "Dynamic Tower," will be a shifting skyscraper of luxury apartments on spinning floors, which will be attached to a central column.
Plans for the project were unveiled in New York by Italian architect David Fisher, who said: "This building will have endless different shapes".
The 420-meter (1,378-foot) building features 80 apartments that spin a full 360 degrees around a central column by means of 79 power-generating wind turbines located between each floor.
The apartments will take between one and three hours to make a complete rotation, and at 30,000 dollars (£15,254) per square meters, will cost between 3.7 million (£1.8 million) to 36 million dollars (£18 million).
Mr Fisher said the skyscraper, which would be energy self sufficient and cost about 700 million dollars (£355 million) to build, was due to be completed in Dubai by 2010
The world's tallest tower, largest mall, longest bridge -- it has them all, or will soon. The new airport complex, under construction about 40 kilometers (25 miles) southwest of old Dubai, is no exception.
At 140 square kilometers (54 square miles), the land set aside by former Dubai ruler Sheikh Rashid bin Saeed Al Maktoum 30 years ago for the visionary $33 billion urban aviation project is almost twice the size of the island of Hong Kong. The heart of this new city, known as Dubai World Central, will be the Al Maktoum International airport. Upon completion, it will be the world's largest airport, bigger than London's Heathrow and Chicago's O'Hare combined.
"It's not just an airport, it's a whole new concept," Abdulla Ahmed Al Qurashi, the head of DWC's aviation division, told MarketWatch in an interview
The sheer dimensions of the $10 billion Al Maktoum airport are difficult to convey. It will have two huge terminals, six concourses, six parallel runways and a smaller terminal for low-cost and regional airlines. The terminals and concourses will be linked by a light railway system.
To give potential partners and investors an idea of what the new airport, and the whole city around it, will look like, DWC has built large models of the project at its headquarters. They are neat and orderly, all perpendicular streets lined with palm trees and pastel-toned buildings. At Al Maktoum, the lights are flashing on the runways and miniature helicopters are on standby on a dozen helipads. The planes are barely an inch long on a model several meters wide.
THE world’s population is expected to climb to nine billion by the middle of the century, from six and a half billion today, according to the United Nations, and a staggering number of those people are likely to be living in big cities.
A pressing question for developers and urban planners is how to accommodate the growing urban masses, especially in developing countries of Asia and Africa. But one point is clear: The skyscraper will play a central role.
Nearly seven years after the collapse of the World Trade Center in New York portended a pullback from cloud-grazing construction, the world is in the midst of a huge wave of tall building construction, both in number and in size. Some 36 buildings rise more than 300 meters, or roughly 1,000 feet, the threshold generally used to define “supertall” buildings, according to the Council on Tall Buildings and Urban Habitat, a nonprofit organization based at the Illinois Institute of Technology. An additional 69 supertalls are under construction, the council estimates.
Some of the most ambitious developments are in the petro-fueled economies of the Middle East and Russia. Among the most anticipated is the $1 billion Burj Dubai, a massive tower being developed by Emaar Properties in the United Arab Emirates. Although it is not yet complete, the tower has already surpassed the current record holder: Taipei 101 in Taiwan
The dust has settled from the Big Dig tunnel collapse in Boston two years ago, but there are still important lessons for engineers to learn from the fatal tragedy, which was easily avoidable.
“The message still hasn’t adequately penetrated enough that when engineers are dealing with new materials, they should use caution with the sources that they rely on,” says Myer Ezrin, a failure analysis expert and former researcher at the University of Connecticut’s Institute of Material Science. “Engineers working with material they have little or no experience with — particularly if it is a life and death matter as it was in the Big Dig — have to investigate the choices and then confirm that investigation.”
In Ezrin’s view, these are the engineering errors made in the ceiling of Boston’s Interstate Connector Tunnel:
The wrong material was chosen as the adhesive to hold up the concrete panels as a suspended ceiling.
There was a communication breakdown between the construction engineers and the resin suppliers’ engineers.
Engineers failed to adequately investigate why anchor bolts using the same adhesive in another tunnel failed in 1999.
Use of a suspended ceiling, particularly one made from concrete, was a mistake in the first place.
On July 10, 2006 a passenger car traveling to Boston’s Logan Airport passed through the D Street portal of the Interstate 90 connector tunnel in Boston, part of a project often referred to as the “Big Dig.” As the car approached the end of the tunnel around 11 p.m., 26 tons of concrete panels fell, killing a passenger. The panels were part of a suspended ceiling anchored to the concrete roof with threaded bolts in an epoxy-filled hole that had been drilled. Massachusetts Attorney General Martha Coakley charged epoxy supplier Powers Fasteners of Brewster, NY, with one count of involuntary manslaughter, which carries a maximum fine of $1,000. Other contractors avoided possible criminal charges with a $450 million settlement with state and federal officials
Rochester, Minn. — Hassan Astaneh's analysis of the 35W bridge collapse concludes that MnDOT, the construction company PCI and URS Corporation, the consulting firm that evaluated the bridge, could have prevented the collapse.
Astaneh is a professor in University of California Berkeley's Civil and Environmental Engineering Department whose work includes studies on the collapse of the World Trade Center for the National Science Foundation. He's been hired as a consultant by one of the lawyers representing some of the victims of the bridge collapse. His paper on the 35W bridge disaster is the keynote address at International Conference on Steel Bridges. Astaneh provided MPR News with an advance copy.
Bridges are designed to bear one and a half to two times their intended weight, Astaneh says. That margin is a safety net that accounts for design errors.
MnDOT had already eaten into the bridge's safety net when it added two inches of concrete to the deck in 1998, Astaneh claims. The 35W bridge deck was nine inches thick. Normally a bridge's deck is six to seven inches thick, Astaneh says.
Innovation can provoke resistance. When a new structural idea is proposed for a building as complex as a modern health care facility, it must satisfy the interests of all the design team members involved, fulfilling their needs for a range of concerns such as schedule, appearance, cost impacts, functionality and constructability.
Teamwork is required to make an innovative idea into a reality. This was certainly the case when new seismic technologies and performance-based designs were introduced on several recent hospital projects.
From lab to job site
After the 1994 Northridge California earthquake, the steel industry was uncertain about how to handle steel moment frame connection design.
Rigorous limitations were imposed on what could be designed without project-specific testing. As a result, heavy steel columns weighing up to 730 pounds per foot were required for a new seven-story, 325,000-square-foot addition to the Sharp Memorial Hospital in San Diego.
After extensive engineering analyses and a thorough search of tested steel moment frame connections, engineers realized the column weight could be cut in half if a deeper column could qualify for the design. The emerging SidePlate proprietary moment framing connection had great potential if project-specific tests could be performed and qualified. The new design would also shave up to $1.8 million off the cost of the project
ROME -- In America, politicians score points with voters by railing against bridges to nowhere. In Italy's election on Sunday and Monday, candidates are worked up about a non-bridge to somewhere.
Shortly after the birth of modern Italy in 1865, the government began preparing to build a two-mile span linking the island of Sicily to the mainland. The bridge, which was to connect the Sicilian city of Messina to the Calabria region on the toe of Italy's boot, was to be the physical symbol of the country's unity.
It has been in the planning ever since, and over the years,
Thursday, February 24, 2011
SHANGHAI—For over three decades the Chinese government dismissed warnings from scientists and environmentalists that its Three Gorges Dam—the world's largest—had the potential of becoming one of China's biggest environmental nightmares. But last fall, denial suddenly gave way to reluctant acceptance that the naysayers were right. Chinese officials staged a sudden about-face, acknowledging for the first time that the massive hydroelectric dam, sandwiched between breathtaking cliffs on the Yangtze River in central China, may be triggering landslides, altering entire ecosystems and causing other serious environmental problems—and, by extension, endangering the millions who live in its shadow.
Government officials have long defended the $24-billion project as a major source of renewable power for an energy-hungry nation and as a way to prevent floods downstream. When complete, the dam will generate 18,000 megawatts of power—eight times that of the U.S.'s Hoover Dam on the Colorado River. But in September, the government official in charge of the project admitted that Three Gorges held "hidden dangers" that could breed disaster. "We can't lower our guard," Wang Xiaofeng, who oversees the project for China's State Council, said during a meeting of Chinese scientists and government reps in Chongqing, an independent municipality of around 31 million abutting the dam. "We simply cannot sacrifice the environment in exchange for temporary economic gain."
The comments appeared to confirm what geologists, biologists and environmentalists had been warning about for years: building a massive hydropower dam in an area that is heavily populated, home to threatened animal and plant species, and crossed by geologic fault lines is a recipe for disaster.
Among the damage wrought: "There's been a lot less rain, a lot more drought, and the potential for increased disease," says George Davis, a tropical medicine specialist at The George Washington University (G.W.) Medical Center in Washington, D.C., who has worked in the Yangtze River Basin and neighboring provinces for 24 years. "When it comes to environmental change, the implementation of the Three Gorges dam and reservoir is the great granddaddy of all changes."
The landmark Forth Rail Bridge will be free of scaffolding and be fully painted by 2012, rail chiefs have announced, killing off one of Britain's best loved idioms.
The specialist paint coating the 118-year-old bridge is expected to last up to 30 years.
Though the restoration work started in 2002, the scale of the task meant bridge bosses have not announced the project's deadline until now.
Network Rail, the bridge operator, has signed a deal worth £74 million with existing contractors, Balfour Beatty, to complete the remainder of the work.
Iain Coucher, Network Rail's chief executive, said: "The Forth Bridge is a working monument to the genius of British railway engineering.
"The work currently being undertaken will restore the bridge to its original condition and preserve the steelwork for decades.
"The team currently working on the bridge has now completed some of the most difficult work and they have already overcome the most significant challenges that this project posed.
"For that reason, we have taken the decision to accelerate the work, increasing the annual investment from £13m to £18.5m with the aim of generating long-term financial savings."
Civil engineering group Strukton, owned by state-owned Dutch Rail, dominates the front page of Tuesday's Telegraaf with its ambitious plans to shift much of Amsterdam's infrastructure underground.
Six-storey car parks could be built underneath the historic canals. Cinemas, shops, gyms, even the household waste disposal system, could all be moved deep into the city's clay soil, Strukton says.
The plan would bring an end to Amsterdam's traffic problems and bad air quality in one go, the company hopes. 'Above ground, the city has become a mess,' Strukton's Bas Obladen tells the paper. 'This plan would make it attractive again to residents and from an economic perspective.'
Struckton puts the cost of the project at €10bn and says it would take 10 to 20 years to complete.
Amsterdam city council executive Tjeerd Herrema points out to news agency ANP that the plan is entirely Strukton's own. 'It does not fit in with my vision of the city,' he says.
The £20m crossing, known locally as the Squinty Bridge, was closed while repairs were ongoing and the crack was found during an inspection.
It is expected that it will be closed for six months, rather than a couple of weeks as had been initially anticipated by engineers.
The River Clyde has now also been shut to all traffic travelling below it.
Glasgow City Council said that the crack was found in a similar component to the one which failed and was removed last week.
Though the bridge was designed to allow for the removal of one of these supports, the impact of the failure of the second is still unclear.
The structure, which spans 140m, is a tied arch design, carrying four traffic lanes. One lane in each direction is reserved for public transport and there are pedestrian and cycle paths.
Running at an angle across the water, it was the first new road bridge over the river to be built since 1969 when it was built at a cost of £20.3m.
A spokesman for Glasgow City Council said public safety was its number one priority and apologised for the inconvenience
The cable, one of 14 which supports the newest bridge over the River Clyde, came crashing down on 14 January.
Designers Halcrow and civil engineering contractor Edmund Nuttall Ltd, who built the bridge, are investigating the cause of the problems.
The bridge between Finnieston and Pacific Quay opened in 2006 and is still under contractor guarantee.
In August, an eight-lane interstate bridge in Minneapolis collapsed during evening rush hour, killing 13 people and injuring 144. This collapse, and the failure to anticipate it, calls into question the adequacy of current bridge inspection methods. Why were problems with the bridge not identified? And if problems were missed in Minneapolis, could they be missed elsewhere? Could this happen again?
There is good reason to worry. Before it collapsed, the Minneapolis bridge was one of more than 70,000 bridges nationwide declared by the Department of Transportation to be structurally deficient. One in three urban bridges fall into this category.
Such bridges may be safe for travel so long as they are carefully monitored. Recent advancements in sensor technology provide the opportunity to collect detailed, real-time data on bridge performance. But this technology is being used on less than a handful of bridges nationwide. Current inspection methods, unfortunately, cannot be relied on to catch a bridge on the brink of collapse.
“We do not know which bridges should be taken out of the system, and which should be maintained,” said A. Emin Aktan, a professor of civil engineering at Drexel University and director of the Intelligent Infrastructure and Transportation Safety Institute.
The road to Europe's largest highway project winds through villages where one sees old women in black head scarves and the occasional horse-drawn cart. Then, on a seemingly deserted plateau, comes a sign with a triangular logo: Transylvania Motorway. Turn left, and suddenly you're in the middle of a small city, with stacks of temporary housing containers, a small mountain of gravel, and a parking lot full of identical Nissan four-wheel-drive pickup trucks.
That's the first incongruous thing in this region that many people associate—inaccurately—with dark castles, primitive forests, and vampires. The second incongruity is Michael John Mix, a barrel-chested American in cowboy boots with a picture on the wall of his office showing himself holding a massive catfish. What's a guy with a Kansas twang doing in the middle of Transylvania? "I like building stuff, you know," Mix says in a deep voice that many a country-and-western singer might envy.
New Infrastructure Attracts Investment
He could hardly have found a better way to do what he likes. Mix is project director for the Bechtel Group in Romania, overseeing construction of a $3.2 billion, 258-mile divided highway that will more than halve the driving time to Western Europe. The Autostrada Transilvania, as it's known in Romanian, is a dramatic example of the kind of emerging market infrastructure projects that are fueling sales for companies such as San Francisco-based Bechtel, Germany's Hochtief (HOTG.DE), and Norway's Aker Kvaerner (AKVER.F).
Romania demonstrates why many emerging countries desperately need such projects if they are to continue their rapid growth. The Romanian economy grew more than 6% in 2007, economists estimate, but the nation could develop even faster if travel and transport were easier. With 22 million people living in a territory the size of Oregon, Romania has fewer than 100 miles of high-speed highway, by some estimates. Airports and railways also need upgrading.
One morning in the summer of 1961 I walked from my house over the hill and down a green slope - a steep path through the grass and bracken - to a Victorian villa that had recently been taken over as offices by a firm of civil engineers. There, on that day, I got my first job. For the duration of the school summer holidays I was to be a chainman, a bag-carrier and hammer-wielder for the surveyors who were planning the approach roads to the new Forth road bridge. Some of the work was pleasant. In an old bedroom, I learned to operate a machine that copied technical drawings. Outside in the sun, I carried theodolites on surveying trips and held up the pole from which a surveyor, waving in the distance, would take his elevations. But other work was hard. Tall staves often needed driving into unyielding ground with sledgehammers. The surveyors, many of whom had learned their craft down Fife's coal mines, would tell me I was useless and do it themselves.
All around me, the landscape I'd grown up with was disappearing. Building the Forth road bridge was "the largest Scottish engineering project of the century". When it had begun three years earlier, people in the village had hardly noticed. A few buildings directly in the bridge's alignment had been vacated, including a farmhouse and another villa, this one at the sea's edge, where as a roving 13-year-old I found a pair of abandoned white spats in the drawing room and hard grapes growing in a cold, untended greenhouse. But now change was in full roar. Cuttings wide enough to fit four carriageways were driven through rock as earth-movers shaped embankments of fresh brown earth. Two 500-foot towers rose above the firth, soon to have steel cables suspended from them, spun on site from 30,000 miles of wire. All of this was happening noisily only several hundred yards from where we lived, but I can't remember protest or complaint. The idea of unchanging rurality is an urban fiction. Our village, North Queensferry, had been changing dramatically for a hundred years, its hills eaten into by whinstone quarries and wartime gun batteries, its houses shadowed by the great Forth railway bridge, which since 1890 had been proclaimed the world's eighth wonder: "The labour of 5,000 men (night and day) for seven years" as the postcards said in the village shop.
Dubai has begun construction on the largest canal project in the Middle East for more than a century, joining a list of mega-projects in the Gulf emirate, the official WAM news agency reported on Monday.
Government-owned real estate developer Limitless this week started excavation work on the 11 billion dollar canal, 75-kilometre (47-mile)-long canal, WAM said.
The "Arabian Canal" will be the biggest project undertaken in the region since work started on the 163-kilometre (101-mile) Suez Canal in 1859.
The canal will be "the largest, most complex civil engineering project ever undertaken in the Middle East," the developers said on their website, adding that construction of the 150-metre (495-feet)-wide canal will take three years.
At six metres (20 feet) deep, it will be able to accommodate vessels up to 40 metres (132 feet) long.
The canal will link two huge artificial palm-shaped islands, currently under construction. The waterway will also pass by the new Al-Maktoum International Airport, which aims to become the world's largest upon completion.
Dubai, one of seven emirates that make up the United Arab Emirates, is the financial and leisure hub of the oil-rich Gulf and is undertaking several other mega-projects designed to more than double the number of tourists annually to 15 million by 2015.
Bridges built from bamboo instead of steel could provide a cheaper, more environmentally sustainable engineering solution in China, a recent experiment suggests.
A novel type of bridge with horizontal beams made from a bamboo composite proved strong enough to support even heavy trucks in tests. The bamboo beams are cheaper and more environmentally friendly to make than steel or concrete, yet offer comparable structural strength.
Yan Xiao, who works at the University of Southern California, in Los Angeles, US, and at Hunan University in China, led the development of the bamboo beams used to make the bridge.
Instead of using round, pole-like pieces of unprocessed bamboo, which have been used as building material for many thousands of years, he came up with a way of assembling timber-like beams from many smaller strips of bamboo.
Precise details on the process remain proprietary, but Xiao says the strips are cut from large stalks of bamboo, arranged in multiple layers, and bonded together with glue. The technique has never been used to build such large beams before, Xiao says
In China bamboo is used for furniture, artwork, building scaffolding, panels for concrete casting and now, truck bridges.
Yan Xiao, a professor at the University of Southern California Viterbi School of Engineering is the designer of a new span in the village of Leiyang, Hunan Province, which formally opens for traffic December 12.
Made from pre-fabricated structural elements, the bridge was erected within a week by a team of eight workers without heavy construction equipment. While traffic on the Leiyang bridge will be limited to the 8-ton design capacity, preliminary tests on a duplicate bridge erected on the campus of Hunan University have shown much higher strength – tests are continuing.
The new bridge is the latest installment in research on structural bamboo being carried on by Xiao, who in addition to his appointment at the USC Sonny Astani Department of Civil and Enviornmental Engineering holds an appointment at the College of Civil Engineering of the Hunan University, China.
Last year, Xiao demonstrated a high capacity bamboo footbridge, which was a featured attraction at a recent conference organized by Xioa in Changsha, China.
Wednesday, February 23, 2011
Mixed-use development for 300,000 inhabitants will rely on the sun for all daytime energy
Engineer Arup is planning the world’s first “solar city” in Phoenix, Arizona.
The prospective 33,000-acre development will include housing for 300,000 people as well as high-tech and commercial schemes.
Arup, which is helping to build the world’s first eco-city at Dongtan near Shanghai in China, will play a civil and engineering role. It is thought work on the site is unlikely to begin before 2010.
Gary Lawrence, Arup’s urban strategy leader, said: “We’ve just signed contracts to do a masterplan in Pheonix and that will be the world’s first completely solar city.”
The town will export energy to the grid in the daytime but will have to import it at night as solar panels cannot produce electricity when the sun is down.
It is thought the project will produce energy through a combination of photovoltaic (PV) panels on houses and solar farm technologies, where heat from the sun is used to generate steam and drive a turbine.
Stray lapwings and gulls flap through the humid air as the tide rises and the mudflats slowly disappear near the Rubber Jetty in a decrepit corner of Mumbai known as Eastern Sewri. There’s no one around but a few ragged boys. On a rare, clear day you can glimpse the high rises of Navi Mumbai, the city that can give India’s commercial capital the space and opportunity to reinvent itself into a truly global megapolis.
There’s one problem. It takes the average commuter two hours to reach Navi Mumbai over rutted roads which, in some stretches, are little more than paths of mud.
That’s why the state government hopes that within a few months, gigantic pillars will begin to rise from the mudflats. The pillars will be the foundation of a 21.75km six-lane bridge—India’s longest—across the sea.
This is Mumbai’s long-awaited link to Nhava across the eastern bay in Navi Mumbai and beyond to the multibillion dollar sprawl of condominiums and industries planned across the eastern seaboard.
In Shanghai, the city Mumbai wishes to be, the sturdy 30km Dong Hai Bridge is the mirror of Mumbai’s Trans-Harbour Link (or just Harbour Bridge as some people call it). The people who created the S-shaped concrete structure don’t consider a bridge as a mere connecting link.
SHANGHAI, Oct. 11 — The Chinese government has announced that it will relocate an additional three million to four million people from the banks of the Yangtze River because of the construction of the Three Gorges Dam.
According to a report by the official Xinhua news agency on Wednesday, the relocations will take place over a period of 10 to 15 years.
They are required because of mounting concerns about pollution in a new lake created by the dam, and because of the proliferation of unforeseen landslides as the riverbank’s walls collapse in many places.
“The reservoir area has a vulnerable ecological environment, and the natural conditions make large-scale urbanization or serious overpopulation impossible here,” said the vice mayor of Chongqing, Yu Yuanmu, according to Xinhua.
Chongqing, one of China’s largest and fastest-growing cities, sits at the western end of the dam’s 400-mile-long reservoir and will absorb many of the displaced people.
Extensive repairs and upgrades to the historic North Torrey Pines Bridge, labeled by the state as “structurally deficient,” should be completed in four to five years.
The city would complete its design and environmental study of the project in 20 to 24 months, and construction would last 24 to 36 months, Del Mar Public Works Director David Scherer told the City Council on Monday night.
“After many years of work, the state and federal highway administrations have given the city – its project – a green light to move forward,” Scherer said.
The 74-year-old, two-lane, seaside bridge received the lowest rating among 87 aging county bridges deemed “structurally deficient” during state inspections in October, scoring 15 out of 100.
During a review of all the state's bridges in the late 1990s, Caltrans determined that the North Torrey Pines Bridge needed seismic retrofitting. The bridge's height and span, and its crossing over a rail line, were factors in determining its rating and meant the improvements were critical, Caltrans said.
Although the bridge is stable and safe for everyday use, it would not survive a major earthquake, California Department of Transportation engineers determined.
On Monday, the City Council approved a contract not to exceed $3 million for Simon Wong Engineering to perform seismic retrofit and rehabilitation design and environmental studies.
Will the levees hold? The US Army Corps of Engineers hopes so, as it pumps water into a canal that burst its banks during Hurricane Katrina to test whether it can now help fight floods.
During Katrina, water flowed into the London Avenue canal in New Orleans from Lake Pontchartrain, instead of the other way around, causing the concrete walls on top of the canal's soil levees to slip and fail. Since then, gates have been built in the lake to prevent water escaping. Currently, water in the canal is 1.2 metres deep, but from 17 August, the Army Corps of Engineers will begin raising the water level in an isolated a 46-metre section of the canal up to 1.5 metres, while monitoring the impact on nearby walls and soil.
Developers are already showing an interest in snapping up plots in the huge Arabian Canal mega-project, which was unveiled on Tuesday by real estate developer Limitless.
Dubai: Developers are already showing an interest in snapping up plots in the huge Arabian Canal mega-project, which was unveiled on Tuesday by real estate developer Limitless.
The vast project is made up of two main parts, an $11 billion canal which will run along a 75 km U-shaped route from Dubai Waterfront to Palm Jumeirah and a $50 billion waterfront 'city', which will cover 33 km of the waterway's southern stretch.
Ian Raine, development manager of Arabian Canal, told Gulf News that Limitless will act as master developer for the waterfront city, setting up the transport and utilities infrastructure and putting up its own buildings, but selling the majority of the space to private developers to construct their own projects.
We will develop a percentage of the project ourselves, but the majority of the land will be sold to third parties. We've already had quite a bit of interest from both local and international third party developers," he said.
However, Raine said plots within phase one of the project are not expected to go on sale until mid-2008.
It was hailed as one of the engineering feats of the 20th century. Now the Three Gorges Dam across China’s mighty Yangtze River threatens to become an environmental catastrophe.
In an unprecedented admission of blame, Communist Party officials gave a stark warning yesterday of impending disaster in the vast area around the dam if preventive measures are not urgently introduced.
For more than a decade China has promoted the world’s biggest hydro-electric project as the best way to end centuries of floods along the basin of the Yangtze and to provide energy to fuel the country’s economic boom.
The Government ignored critics who claimed that the Three Gorges, first proposed nearly a century ago and immortalised in a poem by Mao Zedong, was an ecological disaster waiting to happen.
Now those same officials who oversaw construction of the £13 billion dam admit that surrounding areas are paying a heavy, and potentially calamitous, environmental cost. Hundreds of thousands of people may have to be moved. A total of 1.3 million have been displaced by the dam already.
WASHINGTON, Sept. 24 — The Senate on Monday overwhelmingly approved a bill authorizing $23 billion in water resource projects, including $3.5 billion in work for hurricane-ravaged Louisiana, despite warnings from some lawmakers and watchdog groups that the bill did not provide crucially needed changes to the Army Corps of Engineers, which would do most of the work.
Supporters of the measure, including Senator Barbara Boxer, Democrat of California, the chairwoman of the Environment and Public Works Committee, said it included critical projects for flood control and environmental restoration and would create a new national levee safety program with the goal of better preparedness for hurricanes.
“Communities across the country have waited long enough for the vital projects in this bill,” Ms. Boxer said.
But opponents, led by Senator Russ Feingold, Democrat of Wisconsin, made a forceful, if futile, case that the bill would fail to address the most important needs, even in Louisiana, which is the biggest beneficiary of the measure.
Sept. 20 (Bloomberg) -- San Franciscans soon may have to crane their necks back a bit farther to gaze up at the city's tallest buildings.
City officials are pushing for construction of two office and residential towers of 1,200 feet (366 meters) or more -- at least 80 stories. They would dwarf the Transamerica Pyramid, which at 853 feet has been the tallest building in San Francisco since 1972.
The new structures would challenge the 1,250-foot height of the Empire State Building in New York, the second-tallest U.S. building. It's ``imperative'' for San Francisco to keep pace as super-tall towers spring up around the globe, Mayor Gavin Newsom said in a statement.
``Tall buildings are symbols of cities that don't want to be left behind in a competitive world,'' architect Daniel Libeskind, who worked on designs for towers to replace Manhattan's World Trade Center, said in an interview.
The Transbay Joint Powers Authority, which is supervising redevelopment of the Transbay Terminal site, this morning chose a design by architect Cesar Pelli and named Houston-based developer Hines as the builder. Pelli and Hines prevailed among three groups vying to build a tower as high as 1,375 feet at the southeast corner of First and Mission streets, near the financial district in the South of Market neighborhood.
The tower's pillars now reach to just beneath street level from the bedrock 70 feet below ground level and will eventually rise to 1,776 feet -- symbolic of the date of U.S. independence.
But some say progress at the site has been painful.
State Assembly Speaker Sheldon Silver, a Democrat from lower Manhattan, was blunt this week in his assessment of how long it has taken to get to this point. "The rebuilding process, as we all know, was in a shambles," he said.
After years of scuffling over what would replace the trade center's 110-story Twin Towers, renderings and models of the rebuilding plan have been fine-tuned and the public can now see concrete progress taking place around a sea of cranes at the site.
Next week, the annual September 11 commemoration will take place off site for the first time because what was a gaping hole for the first five anniversaries is now a busy construction site where four new skyscrapers, a transit center, a museum and a memorial are going up.
In addition to the Freedom Tower, due to be completed in 2012, the designs for the three other skyscrapers at the site have been refined to include taller lobbies, space for art, and exterior elevators. The last of those building is scheduled to be finished by 2013.
Monday, February 21, 2011
According to federal and local government officialdom, before Hurricane Katrina struck, New Orleans was not in a floodplain. Obviously, nature thought otherwise.
The striking disparity between government pronouncements and reality highlights the fact that despite the best of intentions, the nation's flood-management policies and uncoordinated federal, state and local efforts ensure a repeat of the Katrina disaster, again and again.
This comes as no surprise to engineers, biologists and floodplain managers. In a recent article in the American Society of Civil Engineers magazine, Civil Engineering, Darryl W. Davis, senior adviser to the U.S. Army Corps of Engineers' Institute for Water Resources, shows how disparate flood-control efforts, land-use planning processes and federal funding criteria results in a dysfunctional approach to flood protection. He writes, "Increasingly substantial evidence suggests that the present approach to managing flood threats in the United States is not sustainable with respect to public safety and economic and environmental consequences. Despite efforts by various levels of government as well as the private sector, flood damage continues to increase, more lives are threatened, and the ecological functions of floodplains continue to be degraded."
The consequences of these dysfunctional approaches are not just a problem in Louisiana. In California, levees line the banks of rivers, confining once extensive streamside forests to thin ribbons of green and ensuring that swift, concentrated floodwaters have ready access to erode and overwhelm vulnerable levees
In the meantime, developers do what they do, aided by local governments pursuing expanded tax revenues. So behind, and often well below, these levees, subdivisions sprout up, lured by government pronouncements that these lands are no longer part of a floodplain and are free from floodplain building and siting requirements.
The good news is that Californians have heard the warnings and are starting to fix the levees. Last November they approved a $4.9 billion bond to fund repairs. But that's not nearly enough to fix the entire system, and residents now face a more vexing problem: deciding where the need is greatest.
This is a challenge that other localities face as they rush to fix aging bridges, roads, rails, and power plants in the wake of the collapse of the I-35W bridge in Minneapolis. Allocating repair money intelligently requires assessing risk accurately. That obliges policymakers to make smart predictions about weather, demographics, and countless other factors.
To guide their choices in the delta, officials are relying on a groundbreaking threat-assessment model devised by a team of 300 top scientists and engineers organized after Hurricane Katrina. It's far from perfect, but it's the most sophisticated tool of its kind ever developed and could one day become a template for guiding infrastructure investment in other areas. "We built a 200-pound bicycle," says team leader Ed (Lewis E.) Link, a senior fellow in civil and environmental engineering at the University of Maryland. "Each time it is used to measure risk in other areas, it will go faster."
Taking a spin on the 200-pound bike gives a sense of the dizzying array of factors to consider in making infrastructure investments. Developed to help organize the emergency reconstruction of New Orleans' flood defenses, the model seeks to analyze a wider range of information than had gone into earlier risk- assessment models
NEW ORLEANS -- A $3 million experiment by the Army Corps of Engineers this week will simulate the conditions that caused critical levee failures during Hurricane Katrina, leading to disastrous flooding.
In the test, engineers will gradually pump water into a section of the London Avenue Canal, one of two canals whose flood walls toppled in the storm two years ago, allowing in most of the inundation in the main part of the city.
As the canal waters rise, engineers will monitor the amount of seepage beneath the flood wall and how much the structure tilts -- while promising nervous neighbors that the test will not cause another breach. The measurements will tell them how much rising water the canal wall can withstand.
Some computations show the wall is going to fail at certain water levels; some show it won't," said Ray Martin, a geotechnical engineer consulting with the Corps on the project. "This experiment will let us know."
The fact that such an experiment is necessary two years after the storm reflects the continuing uncertainty as to exactly what caused the city's flood defenses to fail.
The Yangtze River, flowing more than 3,900 miles from the mountains of Tibet through fertile plains here in Hubei province and on to the East China Sea, was playing its traditional life-giving role Thursday, feeding the Chinese economy as it has for centuries.
As barges laden with goods churned upstream and irrigation canals branched out like capillaries, the river's even flow seemed in many ways remarkable. Other rivers in China have swollen out of their banks, with floods killing about 700 people and causing an estimated $7 billion in damage to buildings and farmland over the past two weeks.
The Yangtze's flow across the Hubei flatlands marks the latest chapter in China's millenary struggle to control its waters. Since before written history began, the river has alternated between giving life to China's farmers through irrigation and killing them through seasonal flooding.
The cycle always seemed beyond man's control. But this year, for the first time, the mammoth Three Gorges Dam, 220 miles upstream from here, was used to regulate the river, releasing limited amounts of water and trapping the excess of summer rains in a huge reservoir.
The engineers who have run the dam since it was finished a year ago said the 606-foot-high structure, the world's largest flood-control and hydroelectric barrier, passed its first real test as the waters peaked Tuesday. Boat traffic was halted as engineers let up to 48,000 cubic meters per second rush through 18 giant sluices. But the rest of the backed-up water stayed on the other side of the 7,575-foot-wide concrete barrier, in a pool stretching back more than 100 miles between steep gorges.
Hubei provincial officials predicted the riverbed could handle the limited flow as it headed downstream to the Yangtze's mouth just north of Shanghai. The water level at Shashi, about 50 miles upstream from here, peaked at the 43-meter danger level, they reported; by Wednesday, it had started to decline.
BEIJING, Aug. 3 (Xinhua) -- Limit the use of private cars, improve public transport and encourage the use of bicycles to curb traffic congestion during the 2008 Olympics, experts from foreign countries advised Beijing on Friday.
Professor Nigel Wilson, of the civil and environmental engineering department of Massachusetts Institute of Technology, said he was "supportive to the limiting of private cars during the Olympic Games", saying that in foreign countries, the method is also adopted during big events, but he was unsure about the approach.
The government planned to keep an average of more than one million cars off the roads to improve traffic flow during the Olympics, said Liu Xiaoming, deputy director of the Beijing Traffic Committee, at the China Planning Network First Urban Transportation Congress
Sharing Wilson's view, Dr. Yoshitsugu Hayashi, dean of the Graduate School of Environmental Studies of Nagoya University, believed the reduction in car use should be achieved not by banning, but through incentives.
"Drivers who don't use their private cars could be given points," he said, "and the points could be exchanged for goods from online shopping."
Dave Wetzel, vice chairman of Transport for London and fellow of the Charted Institute of Logistics and Transport, said private cars were limited in central London by high charges. "Cars going to the central district are charged 16 dollars a day," he said, "so that they could be kept out in a more democratic way than being banned."
Wetzel stressed limiting the use of company cars. "Governmental officials should also be encouraged to use public transportation or ride bicycles," he said, adding that he himself is a bicycle-rider in London.
Matthew Martimo, director of Traffic Engineering with Citilabs, said the bicycle was China's advantage. "Limiting private cars is an idea worth trying but it is just a temporary solution," he said. "The real cause of congestion is high density of people in Beijing and many have cars
VENICE, Italy -- Hundreds of people watched as a new bridge began taking shape over the Canal Grand, the first built in decades over the famed Venice waterway.
Two steel buttresses were put in place on the canal's banks during the weekend. The bridge, designed by Spanish architect Santiago Calatrava, is the fourth over the Grand Canal.
Transporting the buttresses along the canal and under the 16th-century Rialto Bridge was no small feat: Each piece is about 50 feet long and weighs 100 tons.
The bridge will connect the train station to the Piazzale Roma, site of the main bus terminal. Construction is expected to be completed by about year's end; the $13.6 million span will have stone pavings and glass railings.
The project has been beset by controversies over its impact on the city's landscape and access for the disabled, and officials were jubilant over the weekend work.
The new Tacoma Narrows Bridge is making an unexpectedly loud noise when car tires travel over the steel expansion joint at each end.
One neighbor said the impact makes a squeaking sound, while another compared it to traffic crossing a cattle grate. The state Department of Transportation has received a half-dozen complaints since the bridge opened early Monday, spokeswoman Claudia Cornish said.
The DOT will conduct a noise study, and contact the firm that made the joints, she said. The problem could be difficult to solve, she said, because noise walls and sound-absorbing materials typically don't shield houses that sit above a highway, as is the case here
WHEN a country's environment agency slaps 33 restrictions on a construction project, you know it's going to be a controversial one. When that project is likely to cost up to $15 billion, you have to wonder whether business decisions have come ahead of environmental ones.
The Brazilian government this week gave preliminary approval for two huge hydroelectric dams in the Amazon, designed to combat energy shortages. The government claims that the Madeira river dams will meet 8 per cent of the country's electricity demand, and says the 33 restrictions will limit damage.
However, the National Institute for Amazon Research has outlined a string of costly knock-on effects, including the possible extinction of economically and ecologically important fish. They also warn that locals could suffer, because the flooded area will foster malarial mosquitoes, and that the project could lead to international disagreements since the flooded area may extend into neighbouring Bolivia.
WASHINGTON, July 10 — The ceiling collapsed in one of Boston’s Big Dig tunnels a year ago, killing one woman, because builders used the wrong epoxy to hold the anchor bolts in place, the National Transportation Safety Board said Tuesday.
“We’re talking about the wrong glue here, in effect,” said Kitty Higgins, one of the five members of the board, which said that the epoxy selected dried quickly but lost strength weeks later.
A continuing theme of the board’s meeting Tuesday was how small a detail led to the accident. “It’s kind of ironic in a $14 billion project,” said Deborah A. P. Hersman, a board member. “About $1.50 per anchor is what ended up bringing the ceiling down.”
During construction, the builders tested the strength of the bolts; when some failed, the problem was attributed to installation errors, not breakdown of the epoxy.
“The knowledge of the engineering community seems to be deficient,” said Bruce A. Magladry, director of the board’s office of highway safety.
With concrete, steel and asphalt, he said, “once you test them for strength, they essentially keep that strength forever.”
“Epoxy is not that way, it’s a different material,” Mr. Magladry said.
PROSPECT, Me., July 2 — The most breathtaking view in Maine, some say, cannot be seen from the summit of one of the state’s majestic peaks or a bluff overlooking the ocean.
Instead, they say, the best way to see the state’s natural beauty is atop something manufactured — the 420-foot public observation tower of the Penobscot Narrows Bridge and Observatory.
The observation tower, which opened in May and is the only one in the United States, provides an awe-inducing panorama of Maine’s mountains and coastline and a bird’s-eye view of the nearby village of Bucksport. The bridge opened to traffic in December.
The bridge, a 2,120-foot-long span that seems to pop up out of nowhere in this rural area about 20 miles south of Bangor, is being heralded by two very different stakeholders.
Sunday, February 20, 2011
PARIS — As the world's political leaders debate ways to alleviate poverty in Africa, industrialists are moving ahead with their own designs for pan-African development - including the building of the world's largest hydroelectric dam at a bend in the Congo River, between Kinshasa, the capital of the Democratic Republic of Congo, and the Atlantic Ocean.
Called Grand Inga, this giant dam will cost $80 billion to build and will have twice the installed generating capacity of the current record-holder, the Three Gorges Dam in China. Grand Inga would produce enough electricity to serve all of the more than 500 million Africans who currently go without.
While it remains to be seen whether recent leaps in transmission technology are sufficient to carry electricity over Africa's vast distances and physical barriers like the blistering sands of the Sahara, power-hungry countries as far away as Egypt and Nigeria are interested in Grand Inga's potential supply.
"This is a Marshall Plan for Africa," said Gerald Doucet, secretary general of the World Energy Council, the overseer of the project, which is being developed with Westcor - a consortium of power companies from neighboring countries including Namibia, Angola and South Africa - and with international power and engineering giants, including ABB of Sweden, E.ON of Germany, EDF of France, Union Fenosa of Spain and SNC-Lavalin of Canada.
Work is well under way on Santiago Calatrava’s Bridge of Strings at the entrance to Jerusalem. The $55-million steel-and-glass cable-stayed structure has Israel’s longest ever main span at 140 meters. To some activists it also symbolizes the tense relations between Israeli settlers and Palestinians.
Designed by the Spanish architect’s Zurich-based firm Calatrava Valls SA, the curving bridge is part of a 13.8-kilometer light rail line now under construction. The bridge’s slender steel pylon, which soars 118 m above one of the city’s busiest intersections, sits adjacent to a future underground train station for the new Jerusalem and Tel Aviv line. A consortium called Citypass has a 28-year build-operate-transfer contract for the project. It includes French firms Alstom and CGEA Connex, and Israel’s Polar Investments, Harel Insurance and local civil engineering firm Ashtrom. “This is a once-in-a-lifetime proj-ect from an engineering standpoint, with unprecedented international involvement,” says Tzachi Strasser, a civil engineer with Israel’s Gadish Group, project manager on behalf of the client, Moriah, Jerusalem’s municipal-owned development firm.
But that also includes international controversy. France’s Alstom and CGEA Connex are being sued by a pro-Palestinian group in a French court, who say the line serves Jewish settlers living on land “stolen” from Palestinians. A CityPass spokesman contends that the line will serve all residents of Jerusalem and says the issue of Irish unions refusing to train Israeli rail workers is “very insignificant.”
The bridge is designed to cut an S-shaped curve between Jaffa Road and Herzl Boulevard in Jerusalem. A glass embankment running along the bridge’s eastern side will serve as a pedestrian walkway. “This is the first [cabled-stayed] bridge with a curvature of 90° ever built for use by light rail,” says Dan Ben-Amram, planning manager for Moriah. “Initially, Calatrava had proposed using welded steel plates to link the vertical and horizontal parts, but we decided to opt for steel casting on the advice of Cimolai.” Italy-based Cimolai Technology SPA is one of the span’s deck manufacturers on behalf of the contractor, a joint venture of Israel’s Koors Metals and Ramet Ltd.
NEW ORLEANS — An imposing concrete monolith now stands where the canal wall burst and doomed the Lower Ninth Ward during Hurricane Katrina.
The new flood barrier is taller, wider and, by its shape, harder to topple.
But could the rebuilt defenses handle another Katrina?
The answer is no. Even by Army Corps of Engineers estimates, another Katrina would send storm surge from the Gulf of Mexico cascading over the walls that protect the Lower Ninth Ward from inundation.
Standing this week in the front yard of his rebuilt shotgun-style home, carpenter Charles Brown, 48, cast an eye at the nearby wall.
"Everyone knows another big storm would tear that sucker up," he said.
Today, the first day of hurricane season, few dispute that the city is safer than it was before Katrina. But as time passes and rebuilding costs mount, the idea that the federal government will provide protection from the worst of hurricanes here seems ever more remote.
After Katrina's catastrophic inundation, many declared "Never again!" With that message, Congress ordered the Army Corps of Engineers to study how to protect the city from flooding in Category 5 storms, the most devastating on the Saffir-Simpson scale. The idea still has strong political appeal.
"I believe we should order the Corps to achieve Category 5 protection over time," Sen. Hillary Rodham Clinton, D-N.Y., said during a presidential campaign stop recently.
But nearly two years after the storm, with the feasibility of protecting the city to that level still under study, a project to defend New Orleans from less-ferocious storms is proving far more expensive than anticipated. Meanwhile, the Bush administration has signaled that its commitment does not extend to Category 5 protection.
The Golden Gate Bridge of the future will look just like the bridge of the past -- except inside the skeleton of the structure, where it will all be different.
In five years, in time for its 75th birthday on May 27, 2012, the bridge will be stronger, safer and more resistant to earthquakes. But it will be hard to tell the difference.
The bridge district is spending $455 million -- much of it federal money -- on a project to allow the bridge to survive the earthquake everyone knows is coming.
Some of the work has been completed and in the years ahead, the main span -- with a breathtaking 4,200-foot space between the towers -- will be fitted with dampers that work like shock absorbers to keep the bridge standing in a quake.
The dampers allow the bridge to move, so the forces are dissipated. "We want it to be flexible so that it can roll with the punch,'' said Denis Mulligan, the bridge district's chief engineer
Some of the lateral bracing on the trusses under the roadway will be replaced. The rivets driven when the bridge was built in the 1930s will be replaced by newer, stronger bolts, twice as strong as the old rivets.
Coordinating construction of a $2.2 billion transit center in a crowded urban environment would present hardship under most circumstances, but the task of building the World Trade Center Transportation Hub, set to open in 2009, defies even conventional standards.
The project faces exacting space constraints; complicated logistics that include keeping subway service in operation; intense public scrutiny of its design and progress; and one of the world's busiest construction sites, with work on the 2.6-million-sq-ft Freedom Tower, a chiller plant, and the Sept. 11 memorial - as well as three new office towers on the way.
"We have to work closely with all of the stakeholders on a day-to-day basis to reach a consensus on a range of construction issues," says Steve Plate, director of the Priority Capital Programs Department for the Port Authority of New York and New Jersey, which owns the World Trade Center site and will operate the hub.
The new facility, designed by Santiago Calatrava, a Spanish architect, will offer passengers from the Port Authority's PATH transit system an easy transfer point via underground passageways to the subway system operated by New York City Transit. The PATH, which ferries passengers 24 hours a day between various stations in New Jersey and Manhattan, currently uses a temporary station that opened at the World Trade Center in 2003 after the original station was destroyed in the terrorist attacks.
Acting on endorsements and pledges of land from the president of Yemen and the president of the African nation of Djibouti, a Dubai-based developer has tapped an American firm to build a bridge across the Red Sea.
Middle East Development LLC on April 25 issued a notice-to-proceed to Noor City Development Corp., Napa, Calif. It authorizes Noor City, as sole agent, "to proceed with the planning, development, construction and management of the bridge between Yemen and Djibouti."
MED is chaired by Tarek M. Bin Laden. His second-generation company, a powerhouse of construction in the Middle East, labors under the dark reputation of Bin Laden's notorious half-brother, Osama Bin Laden. While Osama's name is an anathema to much of the world, the greater Bin Laden family has a long history of driving major construction and development in the region. Its work continues today with signature projects throughout the region. Tarek Bin Laden turns aside questions about his half brother, saying he has no contact with him and no knowledge of his whereabouts
The newly formed Noor City Development Corp. is led by Tariq E. Ayyad, president. Ayyad is also president of ShareChive LLC, San Francisco, a technology firm with patented systems for delivering constantly refreshed project data to mobile computers on jobsites, with an emphasis on highway and large infrastructure. Ayyad is an American of Kuwaiti extraction, a civil engineer, construction manager and a former bridge engineer with the California Dept. of Transportation.
Bridges are a hot topic when American infrastructure is discussed. A 2005 "report card" issued by the American Society of Civil Engineers reported that, the percentage of the nation's 590,750 bridges rated structurally deficient or functionally obsolete decreased slightly from 28.5 percent to 27.1 percent between 2000 and 2003. That report noted that it would cost $9.4 billion a year for 20 years to eliminate all of the deficiencies on bridges across the U.S., and said that term underinvestment is compounded for the long term by the lack of a federal transportation program.
There are two new bridges, however, that will open to traffic within the next 8 months.
Advanced design presents challenges
For medium length spans (those between 500 feet and 2,800 feet), cable-stayed bridges are becoming the design of choice (see sidebar, Differences between suspension and cable-stayed bridges). Such a bridge is nearing completion in Toledo, Ohio. It will carry heavy, interstate traffic across the Maumee River, to and from industries in Detroit and surrounding areas. An existing drawbridge will remain for local traffic use.
Saturday, February 19, 2011
Golden Gate Bridge is being honored with a national engineering award for a retrofit project meant to help the iconic span withstand a large earthquake, the American Society of Civil Engineers announced this week.
The second phase of the bridge's seismic retrofit project, which allows the suspension span to withstand up to an 8.3 earthquake on the nearby San Andreas fault, beat out four other projects to be named the winner of the ASCE's 2007 Outstanding Civil Engineering Achievement.
The project included major modifications to southern end of the nearly 70-year-old span, the second-largest suspension bridge in the U.S. The largest piece of the retrofit was the strengthening of two 220-foot tall hollow concrete pylons on the bridge's southern side, according to Mary Currie, spokeswoman for the Golden Gate Bridge, Highway and Transportation District.
The project also included the complete replacement of a 235-foot long wall, which faces the ocean; the transformation of the southern viaduct into a "modern steel structure"; and the modification of the Fort Point arch structure.
The Mormon church has drawn criticism from preservationists for replacing the tabernacle’s original pews, made from pine and “grained” by artisans with paint and etchings to appear like oak, the wood favored by Brigham Young, the pioneer Mormon leader. The new pews are made of oak.
The president and prophet of the Church of Jesus Christ of Latter-day Saints, Gordon B. Hinckley, in rededicating the egg-shaped tabernacle on Saturday, said, “With this undertaking, we hope and pray that its historical features have not been destroyed.”
The tabernacle’s famed acoustics, which legend has it enabled a listener to a hear a pin drop from 250 feet away, were measured before the renovation began, modeled on computers and then assessed again recently, said Roger P. Jackson, the project’s lead architect. Mr. Jackson said he expected the building’s enveloping sound would be preserved.
“Acoustics is a science and an art,” he said, “but it’s also guesswork. Anything you do has an impact.”
Church officials declined to talk about the project’s cost but said the money came from members’ tithes, or 10 percent of all income. The church says it has about 12 million members, including 6 million in the United States.
The church spared few expenses on the tabernacle in its seismic retrofitting, especially since seeing the project completed was a personal objective of Mr. Hinckley, 96.
The wooden roof trusses have been girded with steel. The roof’s 44 stone support piers have new steel and concrete reinforcements. Fourteen layers of paint, including one of bird’s-egg blue, were removed from the ceiling. The rostrum, where nearly 100 church leaders sit facing the audience during religious services, can now be lowered with a hydraulic lift and replaced with a stage for an orchestra.
The failure to build New Orleans-area hurricane levees and levee walls as part of an integrated, well-fortified system doomed the region during Katrina and remains the key finding of a revised report released Monday by an investigation team sponsored by the Army Corps of Engineers.
"The system did not perform as a system," concluded members of the Interagency Performance Evaluation Task Force, or IPET, which has spent the past 19 months detailing the causes and effects of Katrina's flooding on the levee system and the metropolitan area.
Katrina's storm surge found a wide variety of weaknesses resulting from the system being built as a series of individual projects: problems such as low levee sections, weak links between levee projects, and failed designs. Those individual failures resulted in water invading the entire protection system, the report concluded.
The report again concludes that "particularly inadequate" designs of levee walls along the 17th Street and London Avenue drainage canals resulted in their failure, despite storm-surge water not overtopping them.
Had the New Orleans area levees been more formidable, such as with armoring or stronger levee walls, damage from Katrina would have been cut dramatically, the report said. It concludes, for example, that half the direct property losses, and much of the indirect damage to the city's economy from the flood, might have been averted if levees and walls had just been overtopped but not breached
Described as an engineering first, rising 4,000ft (1,220m) from the canyon’s floor and 70ft (20m) beyond its rim, the new platform has been dubbed ‘the Skywalk.’
The site is owned by the Hualapai Indians who are hoping to attract visitors to the area, which has high levels of unemployment.
Andy Gallacher, from the BBC said: “For the majority, this is an investment that will bring much needed cash.”
Yet not all of the Hualapai Indians are embracing the Skywalk project with such enthusiasm.
Some tribal members say the new viewing platform is a ‘desecration of sacred ground.’
Dolores Honga, a tribal elder said: “When that Skywalk came about it hit me like I was being stabbed.”
Coupled with this there has also been concern from environmentalists about the effect the new glass bridge will have on one of the world’s greatest natural beauties.
The Skywalk’s construction has been in motion since March 2004 and will open to the public on 28 March.
The platform has been built to hold a capacity of 120 people at any one time.
The glass bridge will be able to withstand winds in excess of 100mph (161km/h), as well as an 8.0-magnitude earthquake within 50 miles (80.5km).
It is believed that former astronaut Edwin Aldrin will be among the first to experience the new walkway.
David Jin, a Las Vegas businessman, originally raised the money to build the Skywalk. However, the Hualapai tribe will be given the platform in exchange for a percentage of the profits gained from the tourist attraction
The last section of a cofferdam built to facilitate construction of the Three Gorges Project from the southern bank of the Yangtze will be blasted away in seconds after 3:00 p.m. Wednesday.
Preparatory work for blowing up this section of the cofferdam downstream the Three Gorges Dam has completed, sources with the Three Gorges Headquarters with China Gezhouba (Group) Corporation, executor of the mission, said Tuesday.
An engineer in charge of the explosion task told Xinhua that they had made 482 holes in the 447.45-meter-long downstream cofferdam and would use 20.5 tons of emulsified explosives, plus 3,896 detonators, to dismantle the temporary protective structure from the upper part.
Civil engineering for downstream power generator workshops on the southern bank of the Yangtze was completed early this year, and a special panel in charge of quality control of the State Council approved the plan for dismantling the cofferdam after having made on-the-spot investigation into the construction site of the Three Gorges Project.
"The earth-and-stone work to be dismantled will total 20,000 cubic meters and the entire explosion will last for 12.36 seconds, " said the engineer.
Grand plans for a link between Africa and Europe, either using a massive suspension bridge or by tunneling under the sea-bed, have been on the drawing boards of dreamers for more than a century. Even Fernand de Lesseps – the French civil engineer who built the Suez Canal and would have cut a similar, though smaller, sea-lane across Gibraltar’s isthmus had the British Government not changed its mind – explored the possibility of a pontoon bridge across the Strait, but discarded it as impractical.
And a few years ago a group of American engineers and academics mooted a suspension bridge which would have had its main anchors on the southern side of the Rock and on the slopes of Jebel Musa – the two original Pillars of Hercules of ancient legend. But this too drifted up the academic chimneys of the MIT’s ivory towers. Certainly no-one in Gibraltar took it seriously.
“Despite decades of dreaming, no one has been able to bridge the physical divide that opened between the two continents more than five million years ago, forming the geological bottleneck to the Mediterranean Sea,” a US expert wrote this week.
But the dreams seem set to change and take shape as reality, according to reports broadcast on the BBC’s Radio Four programme earlier this week and echoed in several American newspapers. This time the governments of Morocco and Spain have taken significant steps to move forward with plans to bore a railroad under the sea-bed of the Strait of Gibraltar.
Gibraltar is left out of the new proposals which would link Cape Malabata in Morocco to Punta Paloma in Spain. This is a far longer route than other proposals, most of which have taken the shortest route between the two continents, linking Tarifa on Spain’s southern tip with the coast near Tangier – a direct line as the seagull flies and a mere nine miles across sometimes treacherous seas. The proposed route would cover some 20 miles.
If built, the project would rank among the world's most ambitious and complex civil engineering feats, alongside the Panama Canal and the Channel Tunnel between Britain and France
TANGIER, Morocco — From the bustling waterfront of this African port city, Europe appears tantalizingly close: The coast of Spain shows on the horizon just nine miles away. Despite decades of dreaming, no one has been able to bridge the physical divide that opened between the two continents more than 5 million years ago, forming the geological bottleneck to the Mediterranean Sea.
In recent months, however, the governments of Morocco and Spain have taken significant steps to move forward with plans to bore a railroad under the muddy bottom of the Strait of Gibraltar. If built, the project would rank among the world's most ambitious and complex civil-engineering feats, alongside the Panama Canal and the Channel Tunnel between Britain and France.
A Gibraltar transportation link has adorned official drawing boards for a quarter-century. After years of slow-moving studies and geological tests, Spain and Morocco gave the project fresh momentum last fall by hiring a Swiss engineering firm to draft blueprints for an underwater rail route. Numerous obstacles remain, and a final decision on whether to build is still a few years away, but optimistic engineers say the project could be completed by 2025.
Government officials on both sides of the Mediterranean say the tunnel would give the economies of southern Europe and North Africa an enormous boost. But the project is being driven at least as much by intangible benefits: the prospect of uniting two continents that culturally and socially remain a world apart despite their geographic proximity
THE engineer who first proposed a tunnel as a replacement for the Forth Road Bridge today welcomed the Scottish Executive's commitment to investigate the plan.
Leading engineer John Carson said he was "delighted" that support was growing for a tunnel, which he said only strengthened his view that it was the only option to replace the ageing bridge
The Evening News reported yesterday how a four-kilometre tunnel was emerging as the favoured option among many engineering experts, politicians, motoring groups and business leaders
And just hours after the story was printed, transport minister Nicol Stephen told MSPs that the Executive was actively considering the option.
Mr Stephen said: "The Executive is committed to building a replacement crossing.
The option of a tunnel does remain open. We have had clear information in the technical assessments which have been done for the need for a new crossing."
Today, Mr Carson said that the minister's announcement proved that building a tunnel was the only way to replace the bridge - which has been affected by corrosion on its cables and could be closed to heavy goods vehicles by 2013.
He added: "This is fabulous news and it shows that a tunnel is the right solution for the Forth crossing. The fact that the Executive are looking seriously at it and the plan is gathering support among politicians and businesses is wonderful.
Retrofitting, rather than replacing, the Alaskan Way Viaduct will cost $2.3 billion, according to a study by the Washington State Department of Transportation.
The numbers, released today, support a memo that viaduct project manager Ron Paananen sent to the city of Seattle and others on Friday. It was in response to a state-funded report by T.Y. Lin International that suggested it was possible to retrofit the aging viaduct, but it would require extensive strengthening of the underground foundations.
The state Department of Transportation has long said it wasn't interested in retrofitting the viaduct, but commissioned the study in response to assertions by retired structural engineer Victor Gray that a retrofit made economic sense.
Gray has said the viaduct could be repaired for $800 million.
"Major roadways in Washington are designed to a higher standard that ensures public safety in the event of a very bad earthquake. Gray's retrofit proposal doesn't meet that standard," wrote Paananen. "While T.Y. Lin has developed a plan that will, it doesn't pencil out. It would only have a 25-year life span and would cost 80 percent of the elevated structure alternative. We also would be left with a structure that has no shoulders and narrow lanes."
The cost of a new elevated structure is estimated at $2.8 billion.
The new numbers, released today, say the cost of a retrofit would be almost as much as a new elevated structure. It said T.Y. Lin has developed a plan that could retrofit the viaduct, but the costs are prohibitive.
"For an earthquake of serious severity likely to have a one in 10 chance of occurring in the next 50 years, the standard would require that the viaduct, though it might be damaged, would still be usable after repairs," said the new state report. "T.Y. Lin's report outlines what would be necessary to meet this standard, including new bracing and other improvements, and also strengthening the footings and piers located in the weak and earthquake vulnerable soil on which the viaduct rests."
The levee system crisscrossing Sacramento and the Central Valley received the biggest financial boost in its long and rickety history when California voters said yes to a $4.1 billion bond measure to strengthen flood control.
The huge infusion of cash should go a long way toward providing more safety to people living behind levees, including residents of Natomas, West Sacramento, the Greenhaven-Pocket neighborhood and other areas of the Sacramento region.
And it is expected to bring a greater level of security to the levee system running through the Sacramento-San Joaquin Delta, where the potential combination of an earthquake and crumbling levees could threaten the water supply of millions of Californians.
Known as Proposition 1E, the measure was approved Tuesday by 64 percent of voters statewide. Coupled with another $800 million in flood control dollars that will flow from Proposition 84, a water-related bond measure, it means nearly $5 billion in state funds will be available for flood safety work.
"It's probably the largest investment for flood control ever _ something that's been sorely needed for a long time," said Les Harder, deputy director of the state Department of Water Resources. "It was gratifying to see that people across the state recognize the dire need."
Raymond Seed, a civil engineering professor at the University of California, Berkeley, said the bond's passage offers California a rare opportunity to attack its flood problems comprehensively.