通过构建横向均匀成层的地震断层模型,利用随机有限断层法,计算了海河断裂发生6.5级地震的地震动分布。计算结果克服了现行综合概率法计算结果不能体现近场效应的缺陷,并反映出断层上盘效应等特点,该结果可作为最大可信地震动应用于抗震设防变形验算,同时还可以作为评价综合概率法结果不确定性的一个参考,对海河断裂影响带的防灾减灾具有一定的借鉴价值。
The Haihe Fault is a major active fault in Tianjin.It is an important basis for the seismologists to determine the potential earthquake sources,and it plays a decisive role for people to select the aseismic design parameters.In this paper,we make a homogeneous layer of horizontal fault model to compute the effect of ground motion of a hypothetic M6.5 earthquake generated by the Haihe Fault using stochastic finite-fault method.The new method overcomes the shortcomings of the integrated probability method that can not reflect the near filed effect.And it reflects the upfault feature.The result from the new method can serve as the maximum credible ground motion to check seismic fortification deformation.The result which is useful for disaster reduction in this zone can also serve as a reference for integrated probability calculations.