In Chongqing Daping Tunnel Out Of The Hole Slope Stability

High slope is one of the most common and basic natural geological environments for human living and engineering activities. With the implementation of the large-scale construction projects, especially the large-scale hydropower projects, opencast mining works and transport projects, in the complex environment and place with complicated geological environments, the stability of natural slopes and artificial high slopes consequently becomes more and more prominent and acute. At present, the slope geological disaster has been known as one of the three main sources of geological disasters in the world, besides earthquakes and volcanoes. The state and local governments have devoted large amounts of labor, material and financial resources for the research and the prevention and rehabilitation of the slope geological disaster. And the prevention of the slope geological disaster has drawn more and more attentions.Based on the slope stability monitoring project of the mouth of the Daping tunnel which is parts of the JiaHua bridge project, and combined with a large number of onsite surveyed data, this paper will research on the slopes beside the mouth of the Daping tunnel. And this research is carried out mainly on the following aspects:①Sum up the status quo and possible future trends of the slope stability research's development through data collections.②Analyze and summarize the main factors and undermining patterns influencing the rock slope stability on the basis of other scholars' rock slope stability studies.③Formulate the rock slope monitoring program for the mouth of the tunnel and the data analysis approach, according to the related data documents, standards, the rock slope instability ways and the onsite conditions.④Formulate the monitoring report, summarizing and analyze the cock slope's deformation condition and the stress condition of the anchor cable and bolt, and conclude the law of the rock slope's deformation process, under the completion of the slope monitoring.⑤By only considering the horizontal force between the different slices, but ignoring the vertical shear stress between central and local authorities, this paper deduces the slope safety factor formulation of gravity increase method, analyzes the causes of the error and infers applicable condition. This study comparatively analyzes the stress-strain relationship between strength reduction method and gravity increase method on slope stability according to safety factor conversion formula of Drucker-Prager yield criterion and Mohr-coulomb yield criterion. The analysis shows that the gravity increase method has a very high precision when the slope safety factor is closer to 1. ⑥By using the ANSYS software, carry out numerical simulation of the mouth of the Daping tunnel, and analyze the developing rule of the slope's stress and strain before and after the reinforcement.