穿越富水断层带隧洞渗流特性正交模拟分析

为了解决福建某引水隧洞开挖过程中产生的(突)涌水问题,采用FLAC3D软件建立隧洞穿越断层破碎带模型。设计了正交模拟试验对不同围岩岩性、隧道埋深及地下水位3个因素下隧洞穿越断层破碎带过程中的渗流作用进行对比。试验结果表明围岩级别对位移影响最大,隧洞埋深影响次之,地下水位影响最小。在此基础上对隧洞进行不同厚度注浆加固设计,解析解与模拟解均表明防渗和加固效果明显。现场施工采用3 m厚注浆圈,穿越断层带引水隧洞的竖向位移和涌水量均得到了有效控制。

Seepage characteristics orthogonal numerical simulation test analysis of the tunnel through water rich fault zone

The study is aimed at exploring a method to solve water inrush problem in the excavation process of a diversion tunnel in Fujian. This paper used the FLAC3D to establish a model of tunnel through fault fracture zone and designed a orthogonal simulation test to compare the seepage of the excavation process under three different factors, including lithology, burial depth and water table. The study of these factors indicates that lithology has the most impact on the vertical displacement and water table has the least impact, the effect of burial is somewhere in between. Based on the test results, a grouting reinforcement design with different thickness was used and the results of simulation and analytic show that seepage control and reinforcement effect are remarkable. The grouting circle whose thickness is 3m was applied in construction and the results showed that the vertical displacement and the water inflow of tunnel through the fault fracture zone are controlled effectively.