Team of Civil Engineers Addresses Future Rebuilding Efforts for JoplinJune 14th, 2011 by DWM Magazine
A team of civil engineers dispatched to Joplin, Mo., by the American Society of Civil Engineers (ASCE), is calling for more stringent building codes and construction techniques in the state. The group says that stronger codes are needed for rebuilding homes and businesses so they can better resist the wind uplift and lateral forces of any future tornadoes, in light of the May 22 tornado that struck Joplin and killed 141 people.
The ASCE group has issued a preliminary report saying that the wind uplift and lateral force continuity techniques that work to protect structures in hurricane-prone regions will work in Joplin to resist wind speeds up to an Enhanced Fujita EF2 level (approximately 135 mph). The formal report is expected to be released in August.
“There was a surprising amount of evidence in the damaged buildings of a lack of connections between building components,” says team leader Dr. David O. Prevatt of the University of Florida.
The team claims that many structures in the area had material deterioration in portions of their framing systems; wood frame roofs were not attached adequately to walls; walls were not attached to floors; and floors were not attached to the foundation with anchor bolts. The group also alleges that there was inadequate attachment between the foundations (walls and piers) to the ground, all of which they say contributed to the building failures in the town.
“It’s apparent that builders have a belief that the weight of the building will keep it in place. That theory is not correct,” says Prevatt. “Positive connections must be made in specific locations if these building components are going to stay connected and for the structure to remain in place.”