GP断层破裂模型在青海门源M_(S)6.9地震强地面运动模拟的适用性研究

Applicability study of the GP fault rupture model in strong ground motion simulation for the Qinghai Menyuan M_(S)6.9 earthquake

2022年1月8日青海省门源县发生M_(S)6.9地震,震中附近遭受了强烈地震破坏.为验证Graves和Pitarka开发的GP断层破裂模型在震前对中国地区地震动场的预测与评估能力,本文基于GP法,考虑不同上升时间系数(rc)的影响,对门源地震进行了确定性地震动模拟.将模拟结果在地震动衰减规律、波形与幅值和烈度分布三个方面分别与青藏地区的地震动峰值预测方程、强震观测记录和根据强震记录自动产出的烈度图进行了对比.结果表明,当rc为9.0时,模拟记录与实测记录和地震动峰值预测方程基本一致.本文较好的重现了门源地震的强震动场,在合理选取rc的情况下,GP法可以应用于中国地区震前强地震动场的预测和估计.

On January 8,2022,a M_(S)6.9 earthquake struck Menyuan County,Qinghai Province.The vicinity of the epicenter suffered strong seismic damage.To verify the ability of the GP fault rupture model developed by Graves and Pitarka in predicting and evaluating the ground motion field in China before the earthquake,this paper performs deterministic ground motion simulations of the Mengyuan earthquake based on the GP method,considering the effects of different rise time coefficients(rc).The simulation results were compared with the ground motion prediction equations of Qinghai-Tibet region,the strong-motion observation records and the intensity maps automatically generated from the strong-motion records in terms of ground motion attenuation pattern,waveform and amplitude,and intensity distribution,respectively.Comparing the waveforms of simulated records from a near-field station and strong earthquake records.The results show that when the rc is 9.0,the simulated records are in good agreement with the measured records and the ground motion prediction equation.This paper reproduces the strong motion field of the Menyuan earthquake.The GP method can be applied to the prediction and estimation of the strong ground motion field before the earthquake in China with a reasonable selection of rc.