Qingsong Station Grade Level Diversion Tunnel Stability Assessment Of Rock

With the strong foundation for the development of construction projects, TBM (Tunnel Boring Machine) increasingly used in tunnel excavation, the surrounding rock of the rock mass quality and stability of the growing depth of understanding, practice shows that the tunnel was built in the surface as a result of a certain depth in the rock and soil, rock and soil encountered in the engineering geology, hydro-geological conditions of the complex and changeable, the current method of engineering geological investigation and technical level, to the quality and stability of rock state to make accurate predictions is very difficult. This article has been based on limited information, combined with the experience of engineering practice QingSing Hydropower diversion tunnel of the rock mass classification and study the stability of surrounding rock. Made in the following the results of exploratory.First of all, the diversion tunnel in this paper to clarify the regional geological and engineering geological conditions of the environment on the basis of the construction through the analysis of the characteristics of TBM, TBM drawn into the quality of construction rock, primarily on the basis of geological factors and the relationship between the efficiency of TBM to determine the specific analysis Construction of the TBM surrounding the impact of factors, made a reasonable classification of the rock mass quality of the quantitative method, using the methods of geological investigation at the scene data, and experimental results of rock mechanics, Ching Chung Station on the diversion tunnel for the rock mass quality classification.Secondly, the use of finite element software MSC.MARC diversion tunnel to carry out self-weight stress field of simulation, to draw water into the tunnel more or less self-weight stress distribution and changes with the topography, as the tunnel depth, and the existence of high ground stress field.Finally, the damaging effects of the factors surrounding rock is divided into human factors and geological factors, an analysis of rock deformation and failure of the way, according to a typical cross-section finite element simulation, and analysis of the stability chambers, part of the lot from the tunnel opening After digging the simulation analysis, the typical lot in the excavation of the tunnel after the changes in displacement and stress analysis of its causes and trends for the tunnel design and construction of reasonably provide an important theoretical basis. This paper is based on the actual Cheongsong Hydropower diversion tunnel completed survey and test data, and analysis and evaluation of results from the water conservancy project construction and geological disasters are important.