Method for testing dynamic strain in protolith

Abstract

The invention relates to a method for testing dynamic strain in protolith, which comprises the following steps of: preparing a measuring hole in an explosive shock wave action area taking a blast hole as a center; preparing a set of mold with a cube-shaped cavity, pouring mortar into the mold, and preparing a test block for simulating physical properties of protolith; pasting a strain gauge on the surface of the prepared test block; preparing a super-dynamic strain tester and a computer, connecting the strain gauges on the surface of the test block with the super-dynamic strain tester through wires, and connecting the super-dynamic strain tester with the computer; feeding the test block into a specified position in the measuring hole and fixing the test block; and controlling the detonators in the blast holes to detonate, collecting data measured by the strain gauges by the super-dynamic strain tester after explosive shock waves pass through the measuring holes, analyzing the collected data by the computer, and automatically calculating stress data. According to the method, the protolith environment and the protolith structure are reserved, the three-way high ground stress field is maintained, the strain measurement error is small, and data are real and reliable.

Description

technical field [0001] The invention belongs to the technical field of rock mechanics testing, in particular to a method for testing dynamic strain inside original rock. Background technique [0002] Deep rock mass is the carrier of deep water conservancy and hydropower projects, deep metal mining, and high-level radioactive nuclear waste disposal. When deep rock mass is excavated, it will be disturbed by blasting and destructive impact, which will often induce a series of damage. The essence of instability and even geological disasters is the critical rupture and dynamic instability of deep rock mass damaged by excavation and unloading under the three-dimensional high ground stress state under the action of blasting shock waves. [0003] At present, in the research on the induction mechanism of deep rock mass failure and instability under three-dimensional high stress, the induction mechanism of blasting impact on deep rock mass disasters is still unclear, and there is a se...

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Problems solved by technology

[0003] At present, in the research on the induction mechanism of deep rock mass failure and instability under three-dimensional high stress, the induction mechanism of blasting impact on deep rock mass disasters is still unclear, and there is a serious lack of basic research results

At present, in the laboratory rock mechanics tests aimed at the critical fracture and dynamic instability of deep rock mass, the rock high strain rate impact test based on the separated Hopkinson pressure bar technology (SHPB) is generally used, but the real rock is ignored in the test. The factor of the three-dimensional high ground stress state in the environment leads to a large difference between the obtained test data and the actual situation, and the reduction factor can only be obtained from experience to reduce the error as much as possible

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