危岩体在地震作用过程中的失稳模式及稳定性评价  

Failure Mode and Stability Evaluation of Unstable Rock during Earthquakes

作　　者：彭宁波[1] 孙博 王逢睿[2,3] 夏江涛[1] 

机构地区：[1]淮阴工学院建筑工程学院,江苏淮安223021 [2]中铁西北科学研究院有限公司,甘肃兰州730000 [3]兰州大学土木工程与力学学院,西部灾害与环境力学教育部重点实验室,甘肃兰州730000

出　　处：《地震工程学报》2016年第6期916-921,共6页China Earthquake Engineering Journal

基　　金：甘肃省科技厅科技支撑计划课题(1304FKCA119)

摘　　要：地震作用过程中地震加速度通常呈先增大后减小的特征。利用拟静力法对危岩的稳定性进行分析时,考虑地震过程中地震加速度的变化,对山西太原天龙山危岩体加固工程中的同一危岩体分别以滑塌式和倾倒式破坏模式进行计算,发现地震作用过程中危岩体可能在两种破坏失稳模式之间相互转化。将此问题扩展至一般情况进行计算并讨论,得出如下结论:地震力对危岩体破坏作用的贡献大小不同,通常情况下,地震作用力对危岩的倾覆力矩贡献相对较大;进行稳定性评价时应考虑地震作用过程,以安全系数最先达到1.0的破坏模式作为危岩体的可能破坏模式进行计算;对危岩体进行抗震加固设计时应对加固设计进行多种工况下的校核,保证其在地震作用过程中不同危险状态的稳定性。During seismicity,seismic acceleration first increases then decreases.Using apseudostatic method and considering the acceleration change during earthquakes,sliding and toppling failure modes were calculated for the unstable rock on Tianlong mountain,Taiyuan city,Shanxi province.We found that the failure mode transformed from sliding to toppling under seismic action.Extending this problem to a general situation,we conclude that:the contribution of seismic forces to unstable rock damage differs and the overturning moment is relatively larger than the sliding force;for stability evaluation,the seismic action process must be considered,and the failure mode of unstable rock whose safety factor first reaches 1.0should be used to calculate the possible mode;to ensure the stability of unstable rock of different risk states under seismic action,the seismic strengthening design should consider different possible failure modes.

关 键 词：拟静力法 地震作用过程 危岩体 破坏模式 稳定性 

分 类 号：TU457[建筑科学—岩土工程]