L型加筋土挡墙地震动力响应理论分析  

Seismic dynamic response theoretical analysis for L-shaped reinforced soil walls

作　　者：彭涛 张晓曦 柯灵 任东兴 何思明[2] PENG Tao;ZHANG Xiaoxi;KE Ling;REN Dongxing;HE Siming(Chengdu Surveying Geotechnical Research Inst.,Co.,Ltd.of MCC,Chengdu 610023,China;Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610299,China)

机构地区：[1]中冶成都勘察研究总院有限公司,四川成都610023 [2]中国科学院、成都山地灾害与环境研究所,四川成都610299

出　　处：《自然灾害学报》2024年第1期212-221,共10页Journal of Natural Disasters

基　　金：国家自然科学基金重大项目(41790433);国家自然科学基金项目(52178311)。

摘　　要：将L型挡墙与加筋土2种柔性支挡结构相结合,充分利用其良好的抗震性能,可用于地震多发区和高烈度区的支挡工程中。研究地震荷载作用下L型加筋土挡墙的破坏机制与动力响应问题。根据第二、第三滑裂面产生条件,提出踵板长度临界系数λ_(cr),以界定长踵板式和短踵板式2种破坏模式。假设填土滑裂面为直线,应用极限分析上限定理,采用Mohr-Coulomb破坏准则,分别建立2种破坏模式下L型加筋土挡墙临界状态方程,推导其地震屈服加速度系数。根据极值原理给出最优解,得到临界屈服加速度系数及其对应的填土滑裂面倾角,分析破坏模式与临界屈服加速度系数受几何参数、物理力学参数和加筋作用的影响。通过算例分析可知:加筋作用可有效地提高L型挡墙的抗震能力,改变其破坏模式;当设计筋材拉伸强度较大时,L型加筋土挡墙只发生长踵板式破坏。The L-shaped retaining wall and reinforced soil are combined to make full advantage of its good seismic performance.It can be used in supporting engineerings in earthquake-prone and high earthquake intensity regions.The failure mechanism and dynamic response of L-shaped reinforced soil retaining wall under earthquake load are studied.In order to define two failure modes of long-heel baseplate and short-heel baseplate,the critical coefficient of heel plate length(λ_(cr))is proposed on the basis of the second and the third slip surface generation conditions.Assume that the backfill sliding surface is a straight line,applying the upper bound theorem and using the Mohr-Coulomb failure criterion,the critical state equations of L-shaped reinforced soil retaining walls under two failure modes are established respectively,as well,the seismic yield acceleration coefficient is derived.The optimal solution is given according to the extremum principle,and the critical yield acceleration coefficient and its corresponding inclination angle of the backfill sliding surface are obtained.The failure modes and critical yield acceleration coefficients affected by geometric parameters,physical and mechanical parameters and tensile strength of bars are analyzed.Through the analysis of the example,it can be seen that the reinforcement structure can effectively improve the seismic capacity of L-shaped retaining wall and change its failure mode.When the tensile strength of the design reinforcement is large enough,L-shaped reinforced soil retaining wall only suffers from long-heel plate failure.

关 键 词：加筋土 L型挡土墙 临界屈服加速度 破坏机制 上限定理 

分 类 号：TU475[建筑科学—结构工程]