Dispatched by the Chinese government,a multidisciplinary team of 30 researchers collaborated with a team from Myanmar to conduct a 14-day on-site investigation.The work encompassed seismic intensity assessments,field ...Dispatched by the Chinese government,a multidisciplinary team of 30 researchers collaborated with a team from Myanmar to conduct a 14-day on-site investigation.The work encompassed seismic intensity assessments,field surveys,and loss evaluations.The paper focuses on the intensity distribution and structural damage characteristics of the 2025 M7.9 Myanmar earthquake,yielding the following key findings.(1)The seismogenic fault rupture propagated in a nearly N-S direction,with a surface rupture length of approximately 450 km.The seismic impact zone exhibited an elongated N-S distribution and a shorter E-W span,distributed like a belt around the seismogenic fault.(2)Within the seismic impact zones,existing buildings comprised five primary structural types,with timber(bamboo)structures constituting the largest proportion(≈80%in rural areas,≈50%in urban areas).The relatively low disaster losses and casualties were primarily attributable to the good seismic performance and low damage ratio of timber(bamboo)structures across varying intensity zones.(3)An anomalous zone of intensityⅨwas located at the boundary between intensityⅥandⅦregions in Nay Pyi Taw.Here,ridge topography combined with soft soil layers significantly amplified ground motion,exacerbating structural damage.(4)Directional effects of ground motion were observed,with the structural damage phenomena and peak ground acceleration(PGA)values in the N-S direction exceeding those in the E-W direction.This validates that the maximum PGA distribution of strike-slip fault earthquakes aligns with the fault strike.The research is expected to provide technical support for post-disaster reconstruction planning,site selection,and disaster mitigation strategies in Myanmar.展开更多
基于EDGRN/EDCMP程序,计算了尼泊尔M_W7.9地震引起的库仑应力变化对强余震的触发作用和对周边断层的加/卸载作用。结果显示:4月25日M_W6.7和4月26日M_W6.8强余震均受到明显触发作用,地震产生的应力场扰动有利于2015年5月12日M_W7.2强余...基于EDGRN/EDCMP程序,计算了尼泊尔M_W7.9地震引起的库仑应力变化对强余震的触发作用和对周边断层的加/卸载作用。结果显示:4月25日M_W6.7和4月26日M_W6.8强余震均受到明显触发作用,地震产生的应力场扰动有利于2015年5月12日M_W7.2强余震的发生。单独反演破裂模型和联合反演破裂模型的计算结果均显示:余震的分布和库仑应力变化的正值区有很好的对应关系,分别有85.5%和75.8%的余震落在库仑应力变化正值区。雅鲁藏布江缝合带西段的西侧受到超过10 k Pa的库仑应力加载。喀喇昆仑断裂、班公错怒江缝合带、格林错断裂的库仑应力加载约为1 k Pa。龙木错—邦达错断裂、玛尼玉树断裂以及嘉黎断裂受本次地震的影响较小。在震中的西北和东北方向,藏南典型南北向伸展构造受到了库仑应力加载作用,量值约为1 k Pa。展开更多
基金National Natural Science Foundation of China under Grant No.U2239252National Natural Science Foundation of China under Grant No.52279128Natural Science Foundation of Heilongjiang Province of China under Grant No.YQ2022E013。
文摘Dispatched by the Chinese government,a multidisciplinary team of 30 researchers collaborated with a team from Myanmar to conduct a 14-day on-site investigation.The work encompassed seismic intensity assessments,field surveys,and loss evaluations.The paper focuses on the intensity distribution and structural damage characteristics of the 2025 M7.9 Myanmar earthquake,yielding the following key findings.(1)The seismogenic fault rupture propagated in a nearly N-S direction,with a surface rupture length of approximately 450 km.The seismic impact zone exhibited an elongated N-S distribution and a shorter E-W span,distributed like a belt around the seismogenic fault.(2)Within the seismic impact zones,existing buildings comprised five primary structural types,with timber(bamboo)structures constituting the largest proportion(≈80%in rural areas,≈50%in urban areas).The relatively low disaster losses and casualties were primarily attributable to the good seismic performance and low damage ratio of timber(bamboo)structures across varying intensity zones.(3)An anomalous zone of intensityⅨwas located at the boundary between intensityⅥandⅦregions in Nay Pyi Taw.Here,ridge topography combined with soft soil layers significantly amplified ground motion,exacerbating structural damage.(4)Directional effects of ground motion were observed,with the structural damage phenomena and peak ground acceleration(PGA)values in the N-S direction exceeding those in the E-W direction.This validates that the maximum PGA distribution of strike-slip fault earthquakes aligns with the fault strike.The research is expected to provide technical support for post-disaster reconstruction planning,site selection,and disaster mitigation strategies in Myanmar.
文摘基于EDGRN/EDCMP程序,计算了尼泊尔M_W7.9地震引起的库仑应力变化对强余震的触发作用和对周边断层的加/卸载作用。结果显示:4月25日M_W6.7和4月26日M_W6.8强余震均受到明显触发作用,地震产生的应力场扰动有利于2015年5月12日M_W7.2强余震的发生。单独反演破裂模型和联合反演破裂模型的计算结果均显示:余震的分布和库仑应力变化的正值区有很好的对应关系,分别有85.5%和75.8%的余震落在库仑应力变化正值区。雅鲁藏布江缝合带西段的西侧受到超过10 k Pa的库仑应力加载。喀喇昆仑断裂、班公错怒江缝合带、格林错断裂的库仑应力加载约为1 k Pa。龙木错—邦达错断裂、玛尼玉树断裂以及嘉黎断裂受本次地震的影响较小。在震中的西北和东北方向,藏南典型南北向伸展构造受到了库仑应力加载作用,量值约为1 k Pa。
