隧道开挖围岩土压力拱效应分析  

Soil Arching Effect during Tunnel Excavation

作　　者：路德春[1] 曹胜涛 张波[1] 杜修力[1] 刘晓峰 

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124 [2]驻中石化北京燕山分公司军事代表室

出　　处：《地下空间与工程学报》2015年第6期1421-1430,1436,共11页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金(51278012;51522802;51538001)

摘　　要：采用弹塑性理论应力反馈算法,研发材料本构模型子程序,将土的应力路径本构模型嵌入大型有限元软件ABAQUS,通过对三轴压缩和三轴拉伸试验条件的数值模拟,验证了子程序的精度。利用二次开发后的ABAQUS对隧道开挖过程进行了三维有限元分析,从不均匀变形、应力重分配、应力路径和地表沉降规律四个方面研究了由重力引起的大主应力改变产生的土压力拱效应。研究结果表明:隧道开挖过程中,围岩土体中的应力路径变化非常复杂,并受几何位置和开挖进程影响;隧道埋深较浅时,土压力拱作用至地表,尚未完全发挥支撑作用,表现为隧道上方土体的整体沉陷变形;隧道埋深较深时,土压力拱的作用未影响至地表,充分发挥了支撑作用,表现为隧道上方土体的塌落变形;土压力拱的作用范围受隧道埋深影响不大,约为隧道半径的3倍。A subroutine program of finite element（ UMAT） was compiled using trial stress return mapping algorithm. Then the stress-path constitutive model of soil is used based on ABAQUS platform. The precision of the UMAT was tested by simulating triaxial compression test and triaxial extension test with ABAQUS. Three-dimensional finite element analysis of tunnel excavation was carried out by secondary developed ABAQUS with the UMAT. The change of maximum principal stress caused by gravity could generate soil arching effect,which was studied through four aspects： uneven deformation,stress redistribution,stress path and the law of ground settlement. The results show：the stress paths of surrounding mass were complex during tunnel excavation and were affected by geometric position;when the tunnel depth was relative shallow,the function of soil arching has been extended to the ground,and the supporting function was not developed fully,present as the whole mass collapse above the tunnel; when tunnel depth was relative deep,the function of soil arching did not reach the ground,supporting function is developed fully,present as a part of mass collapse above the tunnel; the functional range of soil arching was not large,about 3 times as large as the radius of the tunnel.

关 键 词：隧道开挖 拱效应 应力路径 本构模型 

分 类 号：TU443[建筑科学—岩土工程]