A lower limit method for analysis of ultimate bearing capacity of toppling failure of jointed rock slope under earthquake force

Abstract

The invention provides an analysis method of ultimate toppling failure bearing capacity of a jointed rock slope under the action of seismic force, and belongs to the technical field of rock slope stability analysis. According to the method, the jointed rock slope is used as a research object to calculate horizontal or vertical seismic inertial force of rock centroids according to a principle of a pseudo-static method, that is, the seismic inertial force is a function of slope height, rock centroid height and seismic parameters; normal force, shear force and bending moments of internal force of structural surfaces of rocks are used as unknown quantities to establish force and moment balance equations of the rocks; at the same time, yield conditions of toppling failure of the rocks, shear slips of the structural surfaces and tensile detachment are established, overload coefficients of external loads are combined, and a linear mathematical programming model of the lower-bound method of the ultimate bearing capacity of the jointed rock slope on which the toppling failure occurs under the action of seism is established; and finally, a simplex method is adopted to solve ultimate status of the toppling failure of the slope, and an ultimate load or strength reserve coefficient corresponding to a toppling failure mode can be obtained.

Description

technical field [0001] The invention relates to a lower limit method for analyzing the ultimate bearing capacity of jointed rock slope toppling failure, in particular to a rock mass toppling analysis method under the action of earthquake force. The invention belongs to the technical field of rock slope stability analysis. Background technique [0002] my country's mountainous area accounts for more than 60% of the country's land area, and objectively there are a large number of rocky slopes. At the same time, my country is an earthquake-prone country. According to a large number of seismic data surveys, the rock slope instability induced by earthquakes in the central and western regions of my country is the main type of earthquake disaster. , the number of toppling failures of jointed rock slopes ranks second, second only to shear sliding failures. The analysis of the toppling failure bearing capacity of jointed rock slopes has become one of the research hotspots in the fie...

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Problems solved by technology

[0004] (1) The jointed rock slope may suffer from shear slip failure or toppling failure during the earthquake process. Most calculation and analysis methods can only simulate the shear slip failure of the slope, but cannot simulate the toppling failure;

[0005] (2) The dynamic constitutive model of rock mass materials is not yet mature, which limits the application of many numerical calculation methods in seismic analysis;

[0006] (3) Earthquake is a dynamic process, and the criterion for judging whether rock mass failure is shear slip failure or toppling failure needs further study;

[0007] (4) When the rock mass is toppled and damaged, it is difficult to capture the critical limit state by conventional analysis methods

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