Study On Tunnel Surrounding Rock Stability Of Complex Poorly Cemented Sandstone Aquifer

City Tunnel project, including various underground tunnels of the underground railway, highway tunnels, or through the obstacles to solve the problem of urban traffic congestion, as well as various municipal underground engineering and underground civil air defense facilities. With the rapid development of urban construction in China, the size of the cities continue to expand, and the continued growth of the urban population density, many large cities population expansion exists, narrow building space, urban greening to reduce traffic congestion, environmental pollution and a series of problems, including traffic congestion has become a outstanding problems in many of our cities. The tunnel is built in the surrounding rock medium with a certain stress resume and construct signs a cavern structure systems, to stress and hydro-geo-logical factors not only controls the magnitude, frequency, and developmental characteristics of the engineering geological disasters, but also directly affect the ground stability of the tunnel site, the stability of the deep, stability and the stability of surrounding rock of the mountain. Correctly understand and master the basic characteristics of surrounding rock stability of surrounding rock to make the evaluation, not only related to the tunnel design and construction program, but also determines the cost of the entire tunnel project, therefore, in order to ensure the stability of the tunnel project to ensure project construction safety, must be carried out on the tunnel hydro-geo-logical conditions and the surrounding rock stability of the system and in-depth research.Thesis in Cymbidium TAOshupin and HUmaling tunnel project as the basis of the geological survey of the field engineering, field monitoring and geological exploration, laboratory experiments, theoretical analysis and numerical calculation methods, a comprehensive and systematic study of the peach Ping HU ma Ling tunnel hydro-geo-logical and engineering geological features, geological analysis to establish the numerical model, the simulated rock stability with time, the quantitative relationship under different water and different hydro-geo-logical conditions for the region of the tunnel mathematical methods to make the evaluation of the stability of the tunnel surrounding rock. The main research results are as follows:1.Large amounts of data on the region of the tunnel engineering geological survey and geological exploration analysis showed that the Taoshupin tinnel and HUmaling tunnel in the Qin QI middle, Qilian fold system uplift belt in the southeastern end of the region is mainly affected by the pre-SINIAN, ASSEN special-Caledonian, Yan Shan and Himalayan four tectonic cycle, the landscapes of the tunnel area of the loess Plateau of surface water development within each gully seasonal water supply the main source of atmospheric precipitation, compared with water small hole body through regional multi-Tertiary mudstone, sandstone, conglomerate, genesis poor have a greater impact on the construction of the tunnel.2.Using the finite element method computational model for simulation of the ground displacement in the tunnel construction process and the stress distribution, the simulation results show that the excavation of the tunnel influence the stability of the slope, and with the exposure time surrounding rock instability of the phenomenon become increasingly evident.3.Using matter-element theory of tunnel surrounding rock classification. First indicators of access to (the selection of rock strength RC, the RQD value, rock integrity KV value, groundwater status), dimensionless indicator parameter values, and then construct the corresponding classical field objects and sections of domain objects and then determine the weight of each index, and finally obtained through the correlation function corresponding level of the surrounding rock4.Through fuzzy comprehensive evaluation method of the evaluation process with the matter-element theory of the evaluation process compared the results show that the matter element model for analysis of tunnel surrounding rock stability, the method is feasible, the conclusion is reliable from the calculation process look, the law has a clear concept, a simple calculation to evaluate the results of high resolution and.