The use of “severely notched” end connections in the design of timber bridge girders that failed, sending a pair of partly completed pedestrian bridges crashing to the ground—and killing one worker—has come back to haunt the bridge engineer, architect of record and material supplier. The design detail had provoked concerns that were not fully addressed before the November 2014 bridge collapses at Wake Technical Community College in Raleigh, N.C., during an expansion project that involved several buildings and the bridges.
Robert T. Macia, former president of Stewart Engineering, is contesting allegations by the North Carolina Board of Examiners for Engineers and Surveyors that he is “guilty of gross negligence or misconduct.” Macia faces a range of penalties for the design error that could include license suspension or revocation.
Because it can moderate the damaging effects of earthquakes, base-isolation is a technique used primarily in seismically active regions. ENR takes a look at some of the largest applications of base-isolation technologies in the world.