Unloading model test and numerical simulation analysis on high fill loess open cut tunnel with EPS
LI Sheng1,LI Shanzhen1,WANG Qicai1,MA Li2,WANG Qingshi1,XU Wenqi1
(1. College of Civil Engineering,Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China;2. College of Civil Engineering,Lanzhou Institute of Technology,Lanzhou,Gansu 730050,China)
Abstract:In order to study the unloading effect and mechanism of EPS,through the indoor model test,the change rule of vertical earth pressure and soil displacement were studied on trench high fill loess open cut tunnel of load reduction with different densities and thickness EPS. The results show that laying EPS at a certain height of open cut tunnel can change the direction of relative settlement,cause the soil stress redistribution,promote the formation of the soil arch effect and reduce the vertical earth pressure on the top of the open cut tunnel. The smaller EPS density,the bigger the thickness,the vertical earth pressure unloading on the top of open cut tunnel is obvious. At the same time,the vertical earth pressure distribution is decrease→increase→decrease with the increase of distance from the axis as laying EPS,it appears turning point in 0.7 and 1.3 times width. Finally,through the comparison of the numerical simulation and model test,the accuracy of model test and the rationality of selected parameters of numerical simulation are tested. The soil arch effect showing the stress concentration are vividly described by using numerical simulation method,the unloading mechanism of EPS is reveals. The research results can provide reference basis for design and construction of the EPS unloading measures for trench high fill loess open cut tunnel.
李 盛1,李善珍1,王起才1,马 莉 2,王庆石1,徐文启1. EPS板卸载的高填黄土明洞模型试验和数值模拟分析[J]. 岩石力学与工程学报, 2016, 35(S1): 3394-3401.
LI Sheng1,LI Shanzhen1,WANG Qicai1,MA Li2,WANG Qingshi1,XU Wenqi1. Unloading model test and numerical simulation analysis on high fill loess open cut tunnel with EPS. , 2016, 35(S1): 3394-3401.
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