Analysis On The Effect Of Highway Tunnel Gas Migration And Gas-solid Coupling

With the rapid construction of mountain area traffic, highway and railway crossing with high pressure gas tunnel often appear. Previous survey and design in railway and highway tunnel, as far as possible to avoid crossingcoal seam gas area, restricted by various factors, the tunnel had to crossfrom coal seams. This will inevitably encounter in coal gas tunnel construction tunnel. Examples of construction and treatment experience ofthe tunnel through the coal strata mined area and mainly from the railway tunnel in the field, there are few examples of construction of highway tunnel.This study is based on the Dazhou-Wanzhou highway of Tian Ping Zhai tunnel engineering, through establishing the theory model and numerical analysis,and based on the test data, the related key technologies and actively carry out the tunnel through the coal bearing strata, so as to ensure the safety oftunnel through coal measures strata, and provide valuable experience andguidance for follow-up project. The main conclusions are as follows:1, The long-term investigation data as the foundation, by using the analysis results of t he coal bearing strata containing gas and non coal strata of thegas concentration distribution, the relationship between gas concentration and the geological environment and through the change of different coal seam gas concentration on. Also summarized the gas tunnel constructionsite on the disposal.2, Use COMSOL software to establish the model of coupling analysis. Thechanges were studied at different positions from the advanced drilling under coupling gas pore pressure, coal porosity, permeability of coal, thedistribution of coal and rock in different position of gas pore pressure underdifferent flow time. At the same time that changes at different position gasinfluence area and pore pressure.3, Use of gas and coal rock seepage and deformation interactions in thegaseous and solid coupling. The whole process of coal gas seepagecoupling representation of changes in the role of ground stress, gas pressure of coal and rock, and revealed variation under the influence of tunnel construction by the progressive failure of gas seepage and damagebefore and after the nonlinear nature of coalbed gas pressure.4, The use of FLAC3D software, the analysis and determination of gas tunnel in coal construction should be reserved for the safety thicknessrange, to determine the impact of coal seams in tunnel construction of gas.At the same time analysis of highway tunnel construction method of tunnelconstruction of coal, for uncovering coal in help.