The Tunnel Collapse Mechanism And The Dynamic Analysis Of Double-layer Steel Arch Supporting

Along with the development of road and railway construction, mountain tunnelare increasing. Cavern of excavation stability and security is the important content oftunnel engineering management at the grade Ⅳ and Ⅴ surrounding rock. Thefailure mechanism of the tunnel and the supporting has important realistic meaning,and can be optimized to improve the stability of the tunnel structure. This articlebegins from the destructive mechanism of tunnel, using of RFPA2D developed bynortheastern university professor TangChunAn, which is based on finite elementstress analysis and damage of the numerical value, analysis of standard test pieces touniaxial compression test of acoustic emission rule. Through the research on the lawsof the destruction of specimens, understanding the response of destruction after theexcavation of tunnel. This thesis mainly includes the following several aspects：1、 Through extensive reading of the literature material, summarized the tunnelexcavation and supporting conditions and the damage rule of the researchbackground, present situation and developing trend of research method and do a moredetailed analysis.2、when the circle tunnel is curved, finding the sound emission mechanism, andthe damage process is divided into three stages. And the destructive process iscompared. Then we do a simple analysis after tunnel excavation.3、 Situ testing is an important part of safety analysis of the tunnel，Tunnel insitu test is mainly vault settlement analysis and cavern convergence.Tunneling in weak and broken area, the construction unit often uses the double steelarch support, this approach has a simple construction, and a shorter advantages.Through to install the double steel arch support, to analysis the influence of thecontinue excavation of tunnel in broken zone, and finding the double steel archbridge support effect.4、 Since the selection of the physical parameters is mostly decided indoor, sothe model parameters and actually have the certain error. This paper based on thetunnel from Chongqing fruit wood field. The measurement data and softwaresimulation results were analysis by the least square method regression analysis, findthe laws of tested value and simulation value.5、 Dynamic analysis on the double layer steel arch is using on the process of the exaction of tunnel. First of all the wenchuan seismic wave is applying on thebottom of the model. Then using the local seismic by designed on the bottom of themodel, to analysis of stress state of the two lining units.Through the date from on-site measurement and the dynamic analysis we findthat the double steel arch support meets the strength of the next excavation, but itdoes not meet the local seismic requirements.