Research On Tunnel Collaps Mechanism And Treatment Measures In Xiejiahe Tunnel

Along with the rapid economic and social development, infrastructure construction improved fastly in China, in particular, a large number of highways, high-speed railways come out. But being limited by a variety of factors, the highway, high-speed railways often need to cross the mountains, so the construction of the tunnel is particularly important.During the tunnel construction period, water inrush, landslides and other accidents usually come out, especially the tunnel collapse could influence the lives and safety of the construction workers and delay the construction period, and it could also causing huge economic losses and social impacts. Therefore, it is necessary to pay attention to the study on tunnel collapse mechanism and treatment measures. In order to accumulated lessons for future projects, this paper solve XIEJIAHE Tunnel collapse instances for the factors induced landslides, landslides prediction, landslides governance in-depth research, the main research results obtained are as follows:1、According to actual study on collapse analysis of XIEJIAHE Tunnel on in-depth discussion, combined with geological radar detection results, the reason of the collapse of XIEJIAHE Tunnel could be attributed for the following:broken belt, jointed development, shallow and bias buried and improper construction methods.2、For the Measures of the tunnel collapse, this paper analysis the pipe roof support, advanced small pipe grouting reinforcement and surface mortar anchor, then using FLAC3D to simulated its supporting role in order to analyzing the advantages and disadvantages of the various support measures. This paper also provides a reference for the collapse accidents.3、Treatment program for the project are as follows:(1)10Pin118steel gantry erected landslides affect segment within five meters (First branch damaged end chainage start meter) early support reinforcement to ensure the safety of the construction;(2) circumcision damage early support after the collapse of cavity closed20cm sprayed concrete, applied after doing initial support to be collapsed cavity stability, the early support parameter reference class V strengthen (the section steel gantry encryption to0.5m per bay, canceled advanced small pipe system of the arch portion of the anchor, wall anchor lengthened to6m);(3) facilities to do early branch reserved two of (p200concrete pumping tube at the same time, longth of0.5m and3.0m, to bethe cover arch is completed and the formation strength, from1.5m pumping tube pumping concrete to the cavity, the concrete having a thickness of1.5m, play a role in stabilizing buffer is then pumped from3m long pumping tube sand.4、This paper also simulated the effect of the treatment program, the numerical simulation results show that this scheme greatly reduces the crown settlement and clearance convergence and increase the stability of the state of the surrounding rock; At the same time, the support program could also reduce verticalstress and shear stress, improved the stress state of the supporting structure effectively, and it also reduce the range of plastic zone.In addition, the article also related to the construction of information technology, monitoring measurement is an important part of the construction of information technology, the data is the eyes for project’s quality, and it should be paid enough attention in the actual project, monitoring data show that the treatment program of this tunnel is feasible.