Method for determining jointed rock mechanical parameters

Abstract

The invention discloses a method for determining jointed rock mechanical parameters. Aiming at solving the problem that the existing jointed rock mechanical parameters have low reliability, the method comprises the following steps of: 1) measuring the uniaxial compressive strength sigmac of a rock, the flexibility mi of the rock, the GSI (geographical strength index) and the disturbance factor D; 2) estimating the mechanical parameters of rock, such as mass C, phi, sigmat and EH, by Hoek-Brown strength criterion; 3) establishing a numerical calculation model so as to obtain the calculated displacement, comparing with the site displacement so as to obtain a comparison result, and determining whether the strength of the GSI is regulated nor not according to the comparison result; and 4) comparing EH and EB, wherein when (EH-EB) / EH is less than 5%, the deformation parameter E of elasticity modulus is estimated as the deformation parameter EH of the elasticity modulus, then the jointed rock parameter is determined, if not, returning to step 1) and reregulating the strength of the GSI. By combining two theories, the method can determine the reliable jointed rock parameters, and is applicable to rocks with very good quality or cracked rocks or anisotropy rocks.

Description

technical field [0001] The invention relates to a method for determining mechanical parameters of jointed rock mass. Background technique [0002] In the stability evaluation of geotechnical engineering, the design of structure and site support, and the numerical simulation of engineering entities, the study of the determination of engineering rock mechanics parameters is very important. [0003] At present, the commonly used theories for obtaining rock mass mechanical parameters include the rock mass parameter estimation theory based on the Hoek-Brown (hereinafter referred to as H-B) strength criterion and the displacement inversion theory based on numerical simulation. [0004] 1. Rock mass estimation method based on Hoek-Brown criterion [0005] First of all, some parameters need to be input when designing rock excavation engineering, which requires providing a criterion to estimate the strength of rock mass. Based on the analysis of Griffith theory and modified Griffit...

AI Technical Summary

Problems solved by technology

Although the problems of long test period and high cost of indoor and outdoor tests can be avoided, there are still the following problems: (1) The determination of the input parameter GSI mainly depends on geological survey, which has human factors and is relatively subjective; Reasonability is difficult to verify

The latter has the following problems in multi-parameter displacement inversion: (1) the inversion results of E and μ are not unique; (2) C, μ There is a reliability problem with the value

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