Experimental system and method for in-situ measurement of elastic modulus and shear strength of rock mass

Abstract

The invention relates to a system and a method for in-situ measurement of elastic modulus and shear strength of rock mass. The experiment system comprises: a ground fixing and control part, which comprises a working platform, a visualization device, a hydraulic pump and the like, and is used for fixing a test device at a preset position and realizing ground control and feedback of the whole measurement process; an elastic modulus testing device which comprises two rows of drilling pistons and measuring pistons which are positioned in a central sleeve, wherein the measuring pistons can laterally extend into small holes formed by the drilling pistons to measure the in-situ modulus of the rock mass; and a shear strength testing device which is formed by fixing a shear head and a shear plate at the head of a central sleeve through using connecting bolts, wherein the shear strength is calculated by determining shear failure curves of a rock mass under different stresses through graded pressurization of a hydraulic device. The experimental system can simply determine the elastic modulus and the shear strength of the rock mass under the in-situ condition according to the measured data through a point drawing method, and can be widely used for determining the properties of the rock mass in an engineering site.

Description

technical field [0001] The invention relates to the field of geotechnical engineering, and is mainly used for measuring the elastic modulus and shear strength of rock masses below a certain depth on the surface during the construction of geotechnical engineering, and provides reference equipment for engineering practice. Background technique [0002] In geotechnical engineering design and construction, it is necessary to obtain indicators such as deformation parameters and shear strength of rock mass. At present, the determination of rock strength is generally carried out by drilling and coring, that is, after drilling samples are processed into standard specimens in the laboratory, and then converted into on-site rock strength; however, this method will not be available during rock sampling and transportation. Avoid disturbing the rock, and have a relatively large impact on the mechanical properties of the rock. Rock deformation tests are generally done on-site, but such i...

AI Technical Summary

Problems solved by technology

At present, there is no device in my country that integrates rock mass shear strength and rock mass elastic modulus testing. The method of measuring rock mass elastic modulus is mainly to put the pipe directly after drilling, and expand the drill hole as a whole after pressurization. , so that the relationship between deformation and stress is measured

Due to the nature of the rock formation and the impact of drilling on the rock mass, the pressurizing device and the hole wall cannot be fully coupled, which will eventually lead to a relatively large experimental deviation, which is not conducive to the actual construction.

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