Study On The Dynamic Features Of Base Void Area And Grouting Technology Of Xindacheng Tunnel

In recent years, there is a boom in railway development, as while there are more and more railway tunnels. However, the existing railway tunnel bed diseases, which have a serious impact on the safety of railway traffic, have become increasingly prominent. At present, there are few papers doing deep analysis to it. Based on the Xindacheng tunnel, we made deep investigation and analysis on problems existing in the tunnel foundation base, the main contents are as follows:1. By means of geophysical exploration and drilling, we made a deep research on Xindacheng base disease to find out the disease form, distribution paragraphs and causes..2. Using precise level instrument to observe the subsiding deformation of the top surface of the heart of railway and inner rail, and further determine the disease distribution and basement subsidence degree.3. Burring pressure boxes and strain gauges at the section of 1350, 1965, 1970, 2000, 2530 to do on-site dynamic test, and analysis the dynamic stress and strain distribution in different locations.4. We do spectrum analysis on the data of stress and strain with the help of MATLAB program to observe the distribution in the frequency domain, and determine the signal form in order to provide the basis for the later dynamic load of train.5. Drilling core on tunnel base and then do laboratory tests with the cores in order to provide design parameters for numerical simulation. Using finite element software Midas/GTS simulate Xindacheng tunnel under dynamic loading, and then analysis the base stress distribution under normal, unilateral, bilateral, and middle void conditions.6. As well, simulating grouting on void area, and selecting the grouting parameters and then make a brief description of the grouting process.