水位变化下含裂缝非饱和土挡墙的地震主动土压力研究  

Seismic active earth pressure on a retaining wall in unsaturated soils with cracks for changing water table

作　　者：张常光[1,2] 关港辉 李海祥 范家燊 石晶[1] ZHANG Chang-guang;GUAN Gang-hui;LI Hai-xiang;FAN Jia-shen;SHI Jing(School of Civil Engineering,Chang’an University,Xi’an,Shaanxi 710061,China;Stake Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu,Sichuan 610059,Chin)

机构地区：[1]长安大学建筑工程学院,陕西西安710061 [2]成都理工大学地质灾害防治与地质环境保护国家重点实验室,四川成都610059

出　　处：《岩土力学》2023年第6期1575-1584,共10页Rock and Soil Mechanics

基　　金：地质灾害防治与地质环境保护国家重点实验室开放基金(No.SKLGP2020K022);长安大学中央高校基本科研业务费专项资金(No.300102282206);陕西省自然科学基金(No.2021JM-165,No.2021JM-170)。

摘　　要：高烈度区挡墙抗震设计的主要荷载是地震主动土压力。首先根据水位、缝深和墙踵的相对位置关系,提出了含裂缝非饱和土挡墙在高、中、低水位下地震主动土压力分析的3种力学模型;继而通过拟动力法计算墙后滑动土体的地震效应,运用非饱和土力学原理与极限平衡法建立了水位变化下倾斜挡墙的地震主动土压力解答,并给出了迭代应用步骤、对比文献理论解答与振动台实测;最后探讨了水位、缝深以及土体非饱和特性对地震主动土压力系数的影响规律。研究结果表明:所得非饱和土挡墙地震主动土压力解答综合考虑了水位、缝深与土体非饱和特性,能退化为经典土压力公式,与文献理论解答、振动台实测吻合良好且应用较便捷,具有重要理论意义和良好的应用前景;地震主动土压力受水位、缝深、基质吸力、吸力分布与吸力角的影响均很显著,需采用工程措施维持基质吸力、吸力分布、低水位、小缝深等稳定存在以优化挡墙抗震设计。Seismic active earth pressure is the primary load for retaining wall design in high earthquake-intensity areas.Based on the relative position relationship among water table,crack depth and wall heel,this study firstly presented three mechanical models of seismic active earth pressure on retaining walls in unsaturated soils with cracks,which corresponded separately to high/medium/low water tables.The pseudo-dynamic method was then employed to calculate the seismic effect of sliding soils behind a retaining wall.The solution of seismic active earth pressure on inclined retaining walls for changing water table was derived by adopting mechanical principles of unsaturated soils and the limit equilibrium method.The iterative steps to be easily conducted were provided,and the proposed solution was compared with the results of theoretical analysis and the shaking table test available in the literature.Finally,the influences of water table,crack depth and unsaturated soil characteristics on the seismic active earth pressure coefficient were discussed.The results show that the proposed solution well considers the effects of water table,crack depth and unsaturated soil characteristics,which can be degraded to the classical earth pressure equation.Additionally,it agrees well with the existing theoretical solution and measured data of the shaking table test.Consequently,the proposed solution has an important theoretical significance and good application prospect.The influences of water table,crack depth,matric suction,suction distribution and suction angle on the seismic active earth pressure are all apparent.In order to optimize the seismic design of a retaining wall,engineering measures should be taken to maintain stable existence of matric suction,suction distribution,low water table and small crack depth.

关 键 词：地震主动土压力 非饱和土 拟动力法 墙后水位 土体裂缝 

分 类 号：TU476.4[建筑科学—结构工程]