隧洞开挖后渗流量影响因素分析

发布时间：2018-06-12 23:59

本文选题：隧洞 + 渗流　；参考：《铁道建筑》2014年04期

【摘要】：当隧洞穿越高富水地质环境时,在开挖过程中容易产生渗水现象,从而给隧洞的开挖和支护带来不利影响。本文以木里水电工程输水隧洞为例,用离散单元模拟围岩及节理,采用UDEC软件进行数值分析,研究节理倾角、节理间距和洞室埋深对隧洞开挖后渗流量的影响,并对隧洞开挖前后孔隙水压力进行了分析。研究结果表明:在单组平行节理条件下,节理倾角、节理间距和洞室埋深对隧洞开挖后的渗流量都有较大影响;当节理倾角较小时,隧洞洞周渗流受节理倾角的影响不是很明显,当节理倾角超过30°时,洞周渗流量随节理倾角的增加而增加;当节理间距较小时,隧洞洞周渗流量随节理间距的增加呈近似线性增加,当节理间距超过1.5 m时,洞周渗流量基本保持不变;随着洞室埋深的不断增加,隧洞洞周渗流量也增加,当隧洞埋深达到一定值后,洞周渗流量增大的趋势变缓;节理倾角、节理间距及洞室埋深均通过改变开挖前后孔隙水压力差值影响隧洞渗流。
[Abstract]:When the tunnel passes through the high water rich geological environment, it is easy to produce the phenomenon of seepage in the course of excavation, which will bring unfavorable influence to the excavation and support of the tunnel. This paper takes the water conveyance tunnel of Muli Hydropower Project as an example, simulates the surrounding rock and joints with discrete elements, carries out numerical analysis by UDEC software, and studies the influence of joint inclination angle, joint spacing and buried depth of tunnel on seepage discharge after tunnel excavation. The pore water pressure before and after tunnel excavation is analyzed. The results show that under the condition of single parallel joint, joint inclination angle, joint spacing and chamber depth have great influence on the seepage discharge after tunnel excavation, and when the joint inclination angle is small, The percolation around the tunnel is not obviously affected by the joint inclination angle. When the joint inclination angle exceeds 30 掳, the seepage flow around the tunnel increases with the increase of the joint inclination angle, and when the joint spacing is small, The seepage flow around the tunnel increases linearly with the increase of the joint spacing. When the joint spacing exceeds 1.5 m, the percolation flow around the tunnel remains basically unchanged, and with the increasing of the depth of the tunnel, the percolation volume around the tunnel also increases. When the buried depth of the tunnel reaches a certain value, the increasing trend of the seepage flow around the tunnel becomes slower, and the joint dip angle, the joint spacing and the buried depth of the tunnel all affect the seepage flow of the tunnel by changing the difference of pore water pressure before and after excavation.
【作者单位】：西南交通大学交通隧道工程教育部重点实验室;
【基金】：四川省应用基础计划项目(2012JY0095) 国家973计划(2011CB013605) 高铁联合基金重点项目(U1134208)
【分类号】：U452.11

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