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Synthesis of Earthquake Ground Motion

  Another option (Fig. 1a) is the synthesis of seismic ground motion (e.g. Zhang and Deodatis (1996)). The discrete wave number technique is used to propagate waves due to the rupture of an extended seismic source through a 3-D layered half-space. With this method, it is possible to calculate the near-field and the far-field seismic ground motion at any point of a layered viscoelastic half-space, such that the spatial variability of ground motion at distances comparable to the dimensions of engineering structures can be estimated. All types of waves (body and surface) are accounted for in the formulation of the problem. Ground motion time histories with frequency content up to 3 Hz can be calculated. The extent and magnitude of permanent ground deformation can also be computed, which is very important in the earthquake response of large scale engineering structures with relatively low natural frequencies of vibration, such as long span bridges.

Wed Nov 6 14:34:32 EST 1996