渭河断裂西段及其周边区域强地震动预测

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中图分类号：P319.9 文献标志码：A 文章编号：1000-0844（2025）05—1212—09

Abstract： Seismic source and subsurface velocity structure models were established for the western segment of the Weihe fault and its surrounding areas. Existing exploration data were integrated with a hybrid computational approach combining the empirical Green's function method with 3D finite-difference modeling to simulate the rupture process of the fault and obtain the distribution of the strong ground motion field. The results indicated that an Ms7.0 earthquake on the Weihe fault causes the peak ground acceleration to exceed 200gal in most parts of the study area with maximum values of 45O—48O gal. Areas with a high peak ground velocity exhibit an eastwest spatial alignment along the fault with a maximum value of 36cm/s . The peak ground displacement forms a banded distribution around the fault and intensifies eastward with a maximum value of ～14.5cm . The seismic intensity is generally above and can reach IX . Ground motions near the source region surpass the design levels of general engineering structures within specific period bands，with many locations meeting or exceeding the rare earthquake design level （i.e.， 50-year exceedance probability of 2% ），which poses a risk of regional structural damage. These results indicate that enhanced seismic hazard prediction and mitigation measures are urgently needed for the study area.

Keywords： Weihe fault;strong ground motion;peak acceleration;ground motion prediction

0 引言

前人探测结果①②③表明渭河断裂为渭河盆地中重要的次级构造边界，近东西走向，总长约 100km 。（剩余11790字）