Source: International Masonry Institute, Annapolis, Md.
In a preliminary take on the August 23 earthquake, centered in Mineral, Va., IMI National Director of Technical Service David Sovinski notes, “Reinforced masonry structures performed extraordinarily well when you consider that most were not designed for a 5.8 earthquake. This real-world experience supports recent testing done on the behavior of properly designed masonry buildings.
“When you apply laboratory research to proper training for craftworkers and contractors, you have an unbeatable combination: well-designed buildings that are built according to that design. This improves our public safety and the value of our infrastructure.”
The earthquake illustrates common facts and fallacies about building design and construction, he adds. Structural engineers excel at designing structures to handle predictable forces on a building, those coming from the weight of the building itself, plus occupant and environmental loads. Less simple are the occasional, harder-to-predict seismic loads, which operate primarily from side to side, with the force and energy coming in waves. As one wave moves the building to the side, it will continue moving due to inertia briefly until it then begins to return to its original position. As the ground shifts, the building will continue to sway back and forth, occasionally resulting in damage or failure.
A common solution for structural engineers is to stiffen or provide enough ductility for the building to resist seismic loads’ anticipated drift back and forth, Sovinkski explains, adding that a cost-effective solution is reinforced masonry, where the strengths of masonry and steel combine for a system equal to seismic and other building loads.