Spatial Variability of Ground Motion: Seismic Analysis
Coherency; Dynamic; Pseudo-static; Seismic analysis; Spatial variability; SVGM
The seismic design of structures considers that all ground supports are subjected simultaneously to identical seismic excitation. This assumption is not valid for extended structures since it has been recognized that seismic motion exhibits no negligible variability. This variability, called spatial variability of ground motion (SVGM), must hence be considered in the design of extended structures.
Many questions arise: what is SVGM and how does one model it? Does SVGM increase or decrease internal forces of a structure? Is there any general conclusion that can be drawn while considering SVGM?
This entry aims at answering these questions. The first part of this entry addresses the description of SVGM through models in terms of coherency function. Subsequently, the response of structures subjected to SVGM is derived. At this stage, the concept of pseudo-static and dynamic responses is...