Professors To Test Hurricane Resistance To Windblown Debris

Have you ever considered what would happen to your house and your family inside it, if it were to be hit by a hurricane blown object such as a tree limb or timber pole?

UH Mānoa professors Ian Robertson and H. Ronald Riggs of the Civil & Environmental Engineering Department have assembled an unusual experimental apparatus that can provide scientific answers to questions such as these.

With funding support from Hawaiʻi State Civil Defense, Robertson, Riggs and a post-doc student have designed and constructed a "windborne debris test facility" in a warehouse at their sponsor's headquarters inside the Diamond Head Crater.

The test facility consists of a pneumatic cannon that can fire 9 foot long 2x4 timbers at up to 80 mph, and a pressure wall that can apply cyclic internal and external pressure to a wall system to simulate hurricane induced force conditions.

One of the first uses of this test facility will be to evaluate various wall systems that may be used in building safe rooms in residential buildings.

It is anticipated that future building codes in Hawaiʻi and elsewhere will require either strong window protection or a safe room where occupants can seek shelter during hurricanes.

The designs for these safe rooms must first be tested scientifically before they can be included in the building code for new (or optionally retrofitted) residential construction.

Along with collaborator Gary Chock of the Honolulu-based structural engineering firm of Martin & Chock, Robertson will use the test facility to develop economical safe room wall systems for use in Hawaiʻi homes.

The test facility can also be used to evaluate window protection systems developed locally or imported from outside Hawaiʻi.

The windborne debris test facility will go a long way in supplying this valuable and lifesaving knowledge.

"Ian and Gary are perfectly suited by education and practical experience to study this critical element of public safety," said C. S. Papacostas, professor and chair of the Civil & Environmental Engineering Department. "Windblown debris is a major risk to life and limb as well as to property damage during strong-wind events."