Road Tunnel Displacement Inversion And Its Stability Analysis

According to the on-site measured data, the paper founds a set of convenient and practical methods about the back analysis of tunnel displacement and the stability analysis of surrounding rock. When they are applied to the practical engineering, a certain economic performance is obtained. The primary coverage is as follows:Basing on the basal theory about the Neural network and the direct back analysis of displacement, the program on back analysis of displacement is composed with the computer language "Matlab" and testified by some earth-retaining wall.On account of the monitoring data of Miaoya Tunnel, the paper interchanges the parameters of surrounding rock and the coefficient of lateral pressure of in-situ stresses. Further more the paper does research on the stability of the surrounding rock in accord with it. Through the numerical simulation the paper studies the variation law on the displacement of surrounding rock versus the depth of burial and the computation formula is founded. Through analyzing three-dimensional effect of tunnel excavation, the coefficient of three-dimensional effect in Miaoya Tunnel is obtained.Simulating the tunnel with shallow-depth and eccentrical compression with numerical simulation techniques, it is known how the bolt-shotcrete support, the unsymmetrically loading, water and etc. affect on the stability of surrounding rock. Bolt ant shotcreting restrict very much the deformation and the plastic zone. Because of terrains the unsymmetrically loading has an important effect on induced stress field of surrounding rock. So the bias tunnel makes a great difference in the stress field and plastic zone of surrounding rock. The shallow-burial of the tunnel directly changes the stress field of surrounding rock and affects the stability of sidehill. The groundwater makes a very adverse effect on the tunnel with shallow-depth.