| The problem of high rock slope has always been a hot topic in geotechnical engineering,It covers a wide range,from water conservancy and Hydropower Engineering,mining engineering,railway engineering,highway engineering and many other engineering fields to natural fields such as bank slopes and hillsides.In recent years,with the continuous development of social and economic development in China,the scale and intensity of engineering construction are also increasing.More and more attention has been paid to the stability of high rock slope.The study of the weathering and unloading characteristics of the slope is of great significance for evaluating the structural characteristics and stability of the slope.It is of great significance to identify the development characteristics of rock mass structure and predict the stability of dam abutment slope in the later stage of construction and operation supportIn this paper,the field geological survey is taken as the main means to conduct a detailed investigation and Study on the engineering geological characteristics of the high slope in the dam site.On this basis,the possible deformation and failure modes of slopes are summarized.The parameters of strong unloading rock mass are obtained through experiment and engineering analogy.On the basis of qualitative evaluation.The stability of the left bank slope of the upper dam site is calculated by the rigid body limit equilibrium method combined with the three-dimensional numerical simulation.,the specific content and results are as follows:(1)The development and distribution characteristics of three different structural planes(grade III,IV,V)were investigated.The engineering geological classification of the structure plane is carried out.Statistical analysis of the parameters of different level structure planes(2)The weathered zone is divided according to borehole sonic test and adit seismic wave test.(3)Investigation of unload in adit,According to the development characteristics of unloading fractures,the strong unloading,weak unloading zones and ununloading zones are divided.(4)The development characteristics of the structural planes in the adit are investigated,so as to divide the different rock mass structures in the adit..Calculation of the connection rate of the slope structural plane based on the window method,The partition of rock mass according to the ratio of wave speed.(5)According to the criteria of rock mass quality,the quality of slope rock mass is divided,It is concluded that the quality of the main slope rock mass is grade IV and III.(6)The potential failure mode of slope is mainly the combined failure form along the structural plane.A part of the abutment slope.the main part of the rock mass develops from the middle to the steep slope.The unloading cracks in dense unloading zone are densely developed,Universally open,Part of the visible loosening or dislocation can be seen.Mass relaxation of rock mass There are more structural planes outside the steep slope.Under natural condition or excavation condition,unstable sliding is easy to occur along the strong unloading boundary.sliding-tensile fracturing.(7)The engineering geological section of 3 sections of dam abutment is selected to establish generalization model.In Geo-slope,we choose different potential sliding faces to slope,and carry out stability analysis based on rigid body limit equilibrium method.According to the development characteristics of rock mass structural plane and the characteristics of rock deformation and failure,the dam shoulder slope is modeled and analyzed.The calculation results are basically stable.Only H-H section four sliding surface is poor stability under rainstorm and seismic conditions.(8)Based on the Moore's Kulun criterion,The FLAC-3D software is used to simulate the natural conditions and excavation conditions of abutment slope.The basic stability of the slope of the simulated results in two operating conditions. |
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