考虑基坑失稳前土体状态转变效应的非极限主动土压力计算方法  

Calculation method of non-limit active earth pressure considering the soil state transition effect before foundation pit instability

作　　者：曹海莹[1,2] 张书恒 CAO Haiying;ZHANG Shuheng(Key Lab of Green Construction and Intelligent Maintenance for Civil Engineering of Hebei Province,Yanshan University,066004 Qinhuangdao,China;School of Civil Engineering and Mechanics,Yanshan University,066004 Qinhuangdao,China)

机构地区：[1]燕山大学河北省土木工程绿色建造与智能运维重点实验室,秦皇岛066004 [2]燕山大学建筑工程与力学学院,秦皇岛066004

出　　处：《应用力学学报》2023年第6期1374-1383,共10页Chinese Journal of Applied Mechanics

基　　金：中央引导地方科技发展资金资助项目(No.236Z5401G);河北省自然科学基金资助项目(No.E2020203168);河北省高等学校科学技术研究重点资助项目(No.ZD2020330)。

摘　　要：为了拓展深基坑失稳破坏前非极限主动土压力计算的适用范围,依据深基坑失稳破坏前的土体状态转变效应即黏性土类流体特征和墙背扰动域区划分,借助土的流变模型和流体运动动量方程推导出一种考虑时间和位移的非极限主动土压力计算方法;利用COMSOL Multiphysics仿真软件对计算方程进行求解,计算得到深基坑失稳破坏变前关于时间和位移的主动土压力数值。通过与试验实测值和已有文献计算值对比,结果表明,基于基坑失稳破坏前土体状态转变效应的非极限主动土压力计算结果与试验实测值更加接近,误差在3%以内,具有更高的精度;通过对计算模型中的流变参数进行分析,得出土的瞬时弹性模量、黏弹性模量和黏滞系数对非极限主动土压力的影响规律,其中黏滞系数影响最为显著,分析结果对于指导深基坑失稳破坏的防治具有工程指导意义。In order to expand the application scope of non-limit active earth pressure calculation before instability and failure of deep foundation pit,according to the effect of soil state transition effect before the instability of deep foundation pit,that is,the characteristics of viscous soil fluid and the division of wall back disturbance region,a calculation method of non-limit active earth pressure considering time and displacement was derived according to the rheological model of soil and the momentum equation of fluid movement.The COMSOL Multiphysics simulation software was used to solve the calculation equation,and the active earth pressure about time and displacement before instability and failure of deep foundation pit was calculated.The results show that the calculated results of non-limit active earth pressure based on the soil state transition effect before foundation pit failure are closer to the measured values,and the error is less than 3%.Through the analysis of the rheological parameters in the calculation model,the influence of instantaneous elastic modulus,viscoelastic modulus and viscosity coefficient on the non-limit active earth pressure is obtained,and the viscosity coefficient has the most significant influence on the non-limit active earth pressure.The analysis results have engineering guiding significance for the instability and failure prevention of deep foundation pit.

关 键 词：岩土工程 非极限主动土压力 时间 位移 土体流变性 

分 类 号：TU432[建筑科学—岩土工程]