An Upper Limit Method for Analyzing Ultimate Bearing Capacity of Rock Slope Considering Rotation Effect

Abstract

The invention relates to an upper-bound limit analysis method of ultimate bearing capacity of rock slope considering rock translation and rotation effects at the same time, and belongs to the technical field of rock slope bearing capacity analysis. According to the method, based on a plastic upper-bound limit analysis theory, by means of multiple freedom degree rigid block unit discrete jointed rock slope, the translational speed and rotational speed of the rigid block unit centroid are used as unknown quantities, the translation and rotation mechanical effects of rocks are considered at the same time, the overload coefficient of the slope is used as a target function, and plastic flowing conditions satisfying shear failure, tensile failure and rotational failure of a structural plane are constructed; then combined with a virtual work principle and speed boundary conditions, a linear mathematic programming model for working out the ultimate bearing capacity of the jointed rock slope is built, the linear mathematic programming model is solved by means of a simplex method, a strength reserve coefficient is solved by means of an iterative method at the same time, and finally the upper-bound solution and corresponding failure mechanism of the ultimate bearing capacity of the jointed rock slope are acquired. The method has the advantages that the concept is clear and the computational accuracy is high.

Description

technical field [0001] The invention relates to an upper limit method for analyzing the ultimate bearing capacity of jointed rock slopes, in particular to an upper limit method that simultaneously considers the effects of translation and rotation of rock mass, and belongs to the technical field of rock slope bearing capacity analysis. Background technique [0002] There are a large number of structural planes in rock slopes, such as joints, faults, rock layers, shear zones, weak interlayers, etc. The strength and stability of rock slopes depend on the strength and failure mode of structural planes. It is generally believed that jointed rock slopes are composed of rock blocks and structural planes. Jointed rock slopes have the following characteristics: [0003] (1) The faults, joints, and fissures of the rock slope cut each other, the rock blocks are extremely irregular, and the rock mass structure is very complex; [0004] (2) The instability mode of the jointed rock slop...

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Problems solved by technology

[0004] (2) The instability mode of the jointed rock slope is relatively complex. Under the action of external force, the rock slope may experience translational instability, rotational toppling instability, or both simultaneously;

[0007] (1) Although the existing methods have been widely used in practical engineering, there are more or less theoretical deficiencies. For example, the rigid body limit equilibrium method can only analyze simple jointed rock slopes, and the finite element method and The finite difference method has difficulties in simulating complex joint networks and constitutive relations, etc.;

[0008] (2) For the ultimate bearing capacity analysis of jointed rock slopes, the existing methods have not fully considered the translational and rotational effects of rock blocks and the shear failure, tensile failure, and rotational failure of structural planes;

[0009] (3) The theory of the upper limit method is an effective tool for analyzing the ultimate bearing capacity of structures. However, at this stage, there are still many problems to be solved by using the upper limit method to establish a mathematical model that simultaneously considers the translation and rotation effects of rock blocks, and there are few research results.

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