A simple method of conditional random field simulation of ground motions for long structures

The recently developed theoretical framework of conditional random fields i s not widely used for engineering purposes due to its complexity and the di fficulty of estimating the spatial correlation of fields. This paper presen ts a simple method of conditional simulation of space-time variation of a g round motion. The frequency dependence of the spatial correlation function is simplified so that only the correlation of the predominant frequency of the earthquake is taken into account. Numerical simulations of ground motio n fields for long structures conditioned by the El Centro (1940) and Kobe ( 1995) earthquake records are presented. The simulations are performed in th e time domain and three simplified procedures such as: simulation condition ed by one specified record, cumulative and successive simulation, are compa red. (C) 1999 Elsevier Science Ltd. All rights reserved.