摘要
针对黄土地区现有的地震荷载作用下挡土墙土压力计算方法中的不足,进行了4个含水量和3个围压的平面应变试验,首次建立了平面应变强度参数与结构性的关系,扩展了被动状态下考虑应力主轴偏转的粘性土侧土压力系数计算公式,采用水平微分层分析方法,提出了一种地震作用下同时考虑黄土结构性和主应力轴偏转的挡土墙被动土压力计算方法。参数分析结果表明平面应变条件下地震被动土压力均大于三轴条件下,结构性土地震被动土压力大于无结构性土,墙土面有摩擦时地震被动土压力大于墙土面光滑时;地震被动土压力随水平和竖向地震加速度系数的增大而减小、随摩擦角、均布荷载、墙土摩擦角、粘聚力、构度指标的增大而增大。黄土地区地震被动土压力计算应综合考虑平面应变强度参数、结构性和墙土摩擦效应的影响。
There are some drawbacks about the method of existed seismic passive earth pressure calculation in loess areas. Plane strain tests with four water contents and three confining pressures are conducted,the relationship between strength parameters and structure of loess is firstly established here. Formula of lateral earth pressure coefficient considering deflection of stress principal axis is extended in the passive state of cohesive soil. The new calculating method of seismic passive earth pressure simultaneously considering the structure and deflection of principal stress is put forward through horizontal slices analysis. The parametric analysis show the seismic passive earth pressure in the plane strain or having the structure of soil condition is larger than that in triaxial or without structure of soil condition. Friction of soil-wall interface makes seismic passive earth pressure increasing. With the increasing of the horizontal and vertical seismic acceleration coefficients,the seismic passive earth pressure is gradually decreasing. The contrary effects are produced in the friction angle,uniform load,friction angle in the interface of wall and soil,cohesion and structural index. The influence of the strength parameters of plane strain,the structure of soil and the effect of wall-soil friction should be taken into consideration in the calculation of the dynamic earthpressure of the earthquake in the loess area.
作者
陈菲
邵生俊
CHEN Fei;SHAO Shengjun(Institute of Geotechnical Engineering, Xi＇ an University of Technology, Xi＇ an 710048, China;Shaanxi Provincial Key Laboratory of Loess Mechanics and Engineering, Xi＇ an 710048, China)
出处
《地震工程与工程振动》
CSCD
北大核心
2018年第2期72-83,共12页
Earthquake Engineering and Engineering Dynamics
基金
国家自然科学基金项目(41272320
11572245)
陕西省科技厅基金项目(2014JQ5173)~~
关键词
地震被动土压力
平面应变
结构性
主应力轴偏转
黄土
seismic passive earth pressure
plane strain
Structure
deflection of principal stress axis
loess
