The Precast/Prestressed Concrete Institute, concerned about an ominous pattern of spandrel-ledge-punching sheer failures in lab tests of double-tee spandrel-beam assemblies commonly found in parking garages, plans to spend approximately $200,000 to further investigate the situation. During tests on torsion design of loadbearing spandrel beams, punching sheer failures in spandrel ledges occurred at loads substantially less than those predicted by PCI Handbook design equations, according to the institute. No failures have been reported from the field, says PCI. The group, which plans to foot two-thirds of the bill for research costs, is seeking funding from other sources.
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.