Study Of The Deformation And The Stability Of The Expressway Tunnel Through Coal Seam

Based on the numerical analysis method and the construction technology, as well as the monitoring theory, with an example of tunnel project, the deformation and the stability of the expressway tunnel through the coal seam are studied in various point of views during the different phases. The study work and its feature may be summarized as follows:1) The deformation and the change process of the rockmass of the tunnel is controlled by the construction programme and methods. Based on the tunnel engineering geology analysis, with the geologic radar explore technology, the sudden outbrust of coal and gas is forecasted. The construction programme and methods to dig through the coal seam are discussed. To design the explosive methods for excavation and the timbering structure are designed to command the deformation of the rockmass in the construction period in effect. The tunnel ventilation theory and the methods to prevent and cure the gas are introduced in the paper.2) The deformation of the rockmass and the stabilization of the timbering structure is tested by the monitoring measure work. By powerful chart function and analysis forecast function of popular software, the common rule of the deformation of the tunnel through the coal seam is obtained, and the monitoring measure data was regressed. The range of regress constant, the time scope of three deformation phase, the ultimate stability equation of rockmass, and the executive opportunity of the second liner are obtained by regression analysis. The stability of the rockmass, the system of the timbering system, and the feasibility of the style of the digging and explosion in the tunnel are studied based on the locale stress test, which offer in-phase information or pre-information for the construction.3) The deformation rule of the rockmass on the coal seam are summed up by analyzing the managing methods of the goaf of the coal. The math model of the rockmass under the tunnel, which study the law of the stress and deformation, is set up. Based on the study on different coal height, mining style and goaf managing measurements conditions, the deformation rules of the rockmass of the tunnel through the coal seam are obtained with the tunnel example. Thesafeguarding width range and the mining height scope are presented, which protects the tunnel. The measures to control the deformation of tunnel are given at last.