| The landslide caused by fragmental rock slope is a typical disaster in mountainous areas of southwest China.Hoek-Brown(H-B)criterion can be well used to describe the nonlinear strength characteristics of rock mass,while its application is limited in practical engineering due to the insufficiention in quantification of mechanical paramers m_i and structural parameter GSI and the complexity of slope stability calculation process based on this theory.In this paper,the fragmental slope was taken as the research object,combined with rock mechanics test,theoretical analysis and numerical analysis,etc.,to establish the quantitative model of m_i and GSI,construct a new stability calculation method and further explore the motion characteristics of the fragmental slope after failure.The main research results are as follows:(1)There are differences in the influence of water content on the strength of different types of rock mass.The uniaxial compressive strength and tensile strength of rock are affected by rock texture,and the strength of rock with excellent or poor texture is less affected by water.Under the same confining pressure,the strength of saturated rock is lower than that of dry rock.(2)A dimensionless model of strength parameter m_i is constructed.By analysing the data of m_i value,compressive strength and tensile strength of different type rocks from the literatures,the m_i exponentially dimensionless theoretical model based on rock strength ratio is established,and its reliability is verified by comparing different m_icalculation models.(3)A quantitative method of geological strength index(GSI)based on rock block index(RBI)is constructed.Through the comprehensive analysis of core sampling rate,structural plane characteristic parameters and geological strength index,the quantitative method of geological strength index is established.The reduction coefficient of the influence of structural plane orientation and groundwater on rock mass strength is introduced,and the reference value of the correction coefficient is given.(4)A’function+chart’stability calculation method of fragmental rock slope is established.Through theoretical derivation,the theoretical model of stability coefficient based on H-B criterion is constructed,and many stability charts under the influence of multi-source parameters are abtained by numerical analysis method.Considering the slope height influence weight factor f _H and slope influence weight factor f_β,the quantitative expression of slope stability coefficient with arbitrary geometric characteristics is established.(5)The movement process of the cataclastic structure collapse body is simulated.The stability coefficients of Zhangjiawan slope under different project conditions are calculated by using the stability quantification model.Through Roc Pro3D software,a three-dimensional geological model of Zhangjiawan slope is constructed,to explore the influence of block size on motion speed,energy and bounce height by considering the particle size block index. |
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