Author(s)

L. Haiming, T. Xiaxin, S. Xiaodan & L. Ping

Abstract

Earthquake disasters are caused mainly from the damage and collapse of engineering structures, and the latter is mainly made by strong ground motion during the event. As city areas and scales of engineering structures are getting larger and larger in recent years, more than ever before, the forecast of strong ground motion field is emphasized. From a case study at Lanzhou city of China, a new developed approach is introduced in this paper. A hybrid source model that combines Asperity model with a K squire model is adopted. The high frequency motion is synthesized by random procedure and low frequency motion is calculated by a simplified numerical Green Function procedure, the two are combined in time domain after high and low pass filtered separately. Finally, the application of the result in the disaster reduction of the city is suggested. Keywords: forecast, ground motion field，hybrid source model, random synthesis, numerical green function. 1 Introduction In the development of modern cities, more and more large horizontal dimension structures, such as long span structures, fly-over crossings and buried pipelines have been built up in urban areas. Damage of those structures in an earthquake will cause large losses to the city. Thus, disaster risk assessments and reductions for cities, especially for those located near or above active faults, are emphasized in earthquake engineering field. Engineering countermeasures for the risk must

Keywords

forecast, ground motion field，hybrid source model, random synthesis, numerical green function.