Method for theoretically calculating macro shear strength of large-scale bed rocks

Abstract

The invention discloses a method for theoretically calculating macro shear strength of large-scale bed rocks. The method comprises the following steps of: extracting a cube (as shown in the specification) which comprises enough rock masses same as a test piece in the aspect of size from a large-scale batholith, and taking the cube as a rock mass macro feature unit; defining the rock masses same asthe test piece in the aspect of size as small-scale rock mass feature units; determining a mean value (as shown in the specification) and a variance (as shown in the specification) of small-scale friction coefficients of the small-scale rock mass feature units, a mean value (as shown in the specification) and a variance (as shown in the specification) of small-scale cohesive force of the small-scale rock mass feature units, and correlation coefficients <rho>fc between the small-scale friction coefficients and the cohesive force according to small-scale rock mass shearing test data; determining macro positive stress <sigma>n , on a dangerous sliding surface, of the rock mass macro feature unit; and calculating rock mass macro shear stress. According to the method provided by the invention,macro shear stress of large-scale bed rocks is determined according to shearing test results of small-scale rock mass test blocks, so that experiences and semi-experience performance of traditional methods are overcome, and mechanical characteristics of rock masses can be reflected more truly.

Description

technical field [0001] The invention relates to geotechnical engineering technology, in particular to a theoretical calculation method for macro-shear strength of large-scale bedrock. Background technique [0002] In water conservancy and hydropower, geotechnical and other projects, large-scale natural rock foundations are often encountered, and the specimens that people can use to test their mechanical properties are often small, and the mechanical parameters measured by the test show great dispersion. Its mechanical properties are not constant like deterministic homogeneous materials, but change with the change of spatial position. Since the strength and deformation characteristics of bedrock are extremely important influencing factors in engineering design, whether the mechanical property parameters such as shear friction coefficient and cohesive force of rock mass can be correctly selected in the design is related to whether high dams, etc. can be ensured. The safety an...

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Problems solved by technology

[0003] As for the shear strength parameters of large-scale bedrock, from the research status at home and abroad, the values ​​and sorting methods of rock mass mechanical parameters are different in different countries, but due to the lack of calculation formulas with sufficient theoretical basis, the current engineering is basically It is determined by using the test results of small-scale test blocks and relying on empirical and semi-empirical methods

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