Do the latest tilt-up designs follow recent advanced design concepts for seismic loading so that earthquake frequencies do not set up resonances in structures? How did tilt-up structures perform in the 1971 San Fernando earthquake where the Mercator scale reading was 6.5?
It is probably not possible to prevent development of resonance from earthquake frequencies transmitted to a tilt-up structure, but it should be possible to accommodate the energy. Actually tilt-up construction has been widely used in Earthquake Zone 3 because of its resistance to earthquake damage, and in general tilt-up buildings survived well in the 1971 quake. There was a small number of tilt-up buildings that did suffer damage in the 1971 quake but these were buildings in which the connections failed between the wall and the roof. During an earthquake a large amount of energy comes into the wall through roof diaphragm action. When connections are not strong enough to withstand the force the wall may fall, since walls of one-story buildings often depend partly on the roof for support. Several wall panels tore themselves loose during the 1971 quake. A few came down. There are connections for tilt-up walls that do withstand earthquake forces but we have no knowledge of a code that describes them. Efforts are being made to improve codes so that connections used for tilt-up construction will be adequate.