THE EFFECTS OF SOIL THICKNESS ON REVERSE FAULT RUPTURE PROPAGATION

Fault setbacks or avoidance of construction in the proximity to seismically active faults, are usually supposed as the first priority by building codes and regulations. For instance, the well-known Alquist-Priolo Earthquake Fault Zoning Act of the State of California stipulates a setback of 50ft (15.3m) from each side of active fault traces, whereas the Iranian and the European seismic codes forbade any construction within the "immediate vicinity” of active fault traces. In this paper, based on some 1-g physical modeling tests, the effects of soil thickness on reverse fault rupture propagation are presented. It is observed that without consideration of the effects of soil thickness on surface fault rupture propagation, the setback provision does not give generally enough assurance for reverse faults.