In the wake of Sept. 19’s magnitude-7.1 earthquake that killed at least 369 people in Mexico, geotechnical engineers are calling for routine site-response analyses during design to ensure structures in high seismic zones are not “in tune” with their soil. Much of the damage to some 1,000 buildings—and the majority of the 44 collapses—in Mexico City was a consequence of the dangerous alignment of the resonant frequencies of the quake, the soil and the buildings—a known hazard well beyond Mexico, say the experts.
Every city in a high seismic zone is at risk, says geotechnical engineer Kevin W. Franke, a Brigham Young University professor of civil engineering. “We do not want our structures to be in tune with the soil.”