ABSTRACT
Most earthquakes involve a sudden release of energy as rock masses in the Earth’s crust fracture due to tectonic faulting. Some are also associated with volcanic processes, landslides, large explosions, or even ground loading from the filling of large reservoirs. Following an earthquake, energy propagates outward from the source in the form of elastic
seismic waves
. The duration, amplitude, and frequency characteristics of these waves are a function of the type and
magnitude
of the earthquake, the distance from the
epicenter
, and the type and distribution of geologic materials through which the waves travel. Structures located along the way are subject to shaking and may experience damage or even fail catastrophically. Whereas the broad field of earthquake engineering deals with all of these aspects, the perspective of geotechnical engineers is often more site-specific, dealing with issues relating to the propagation of seismic waves through soil and rock layers close to the ground surface, the effects that shaking has on ground displacements and stresses, as well as on civil engineering structures such as dams, slopes, retaining walls, foundations, and lifelines. A proper understanding of geotechnical earthquake engineering principles is necessary for rational and sound earthquake-resistant design. The focus of this chapter is on geotechnical aspects. The reader is directed to the rest of this volume for additional topics on earthquake engineering.
