An Experimental Study Of The Characteristics Of Tunnel Water Burst In Fault Fracture Zone

With the development of Chinese transportation construction and tunnel construction techniques in recent years, the tunnel project turns to be characterized by larger buried depth,longer tunnel line, more complicated geological interference, and more frequent disaster-induced destruction. Among all the blocks of tunnel construction, water inrush disaster in fault fracture zone has become one of the major geological disasters leading in casualties and economic losses. Therefore, it is of great significance to conduct an experimental study and analysis on the variation characteristics of water inrush, water pressure, water transfusion, and wall rock displacement when water inrush emerges at the against-inrush safety thickness of rock strata and tunnel in the fault fracture zone.In the case of Cenxi-Shuiwen highway tunnel project, this thesis studies the tunnel in the fault fracture zone by theoretically analyzing the results of model tests and numerical simulation. The characteristics of water inrush in tunneling under gravity have been investigated under three working conditions: tunneling with no surface water recharge or grouting; tunneling with surface water recharge and no grouting; tunneling with surface water recharge and grouting.The major research and conclusions are as follows:a.This paper designs the laboratory model experiments on the basis of similarity theory by introducing geometric resemblance constants(lC =80), unit weight resemblance constants(?C =1) andosmotic coefficient resemblance constants(kC =1).b.In light of the mathematical analysis on the water inrush features under three working conditions as aforesaid, the paper draws a conclusion on the variation rule of water inflow,water pressure, water transfusion and rock wall displacement when water inrush emerges at the against-inrush safety thickness of rock strata and tunnel in the fault fracture zone.c.This paper employs MIDAS/GTS to conduct numerical modeling on the laboratory model experiments of three working conditions and compares the analysis results with the practical results of the experiments, whereby the features of water inrush in the fault fracture zone can be found. This finding is expected to shedding some light on the prevention and treatment of water inrush of tunnel project.