Author(s)

T. Xiaxin, S. Xiaodan, L. Haiming,1 & L. Ping

Abstract

Conjugated with the paper of \“Forecast of strong ground motion field near the fault for earthquake disaster reduction in urban area”, this paper discusses the issues in the forecast that need to be further dealt with. The first is the field must be estimated from the same source model, rather than taking the average motion at a site from more than 30 source model in the current seismic hazard assessment practice. The second is in the random synthesis, the uncertainty on envelop of motion time history from a sub source must be treated in the same way for all ground points rather than randomly varying in the current practice. The third is the uncertainty on the rupture velocity must not be changed randomly in the synthesis. The fourth is the order of the filters and the integrations of accelerations and velocities of the high and low frequency motions before being combined together. From a sensitivity analysis, the consequences of the above issues are presented and further study is suggested. Keywords: forecast, ground motion field, source model, uncertainty, filter and integration. 1 Introduction A set of approaches for forecasting strong ground motion at engineering site is developed in these years (Hanks and McGuire [8]; Beresenv and Atkinson [4]; Somerville et al. [16]; Atkinson and Silva [2]; Irikura [10]; Tao and Wang [18]), and are applied for disaster reduction in some engineering projects and urban areas (Boatwright and Choy [6]; Beresenv and Atkinson [5]; Liu et al. [12]). For a large city or long span structure, a ground motion field is required for seismic

Keywords

forecast, ground motion field, source model, uncertainty, filter and integration.