Curvograms of Strong Earthquake Ground Motion

Abstract

A method for the synthetic generation of curvograms (curvature versus time) associated with strong earthquake shaking is presented. It is shown that small radii of curvative of ground motion, in the range of several hundred meters, are possible only for very large accelerations (1–3 ge/u), near epicenter, and in soft geologic and soil environment, with shear wave velocities in the range near 50–100 m/s. Therefore, the pseudostatic bending of long foundation structures by ground waves may be expected only for large accelerations and for short wavelengths, in the vicinity of shallow or surface faults. Similar conditions are possible in isolated areas, where the three-dimensional geometry of surface layers leads to focusing, and thus large amplification of incident wave amplitudes.