A preparation and determination method of impact damaged rock samples based on shpb test

Abstract

The invention discloses an impact damage rock sample preparation and assay method based on an SHPB test and belongs to damage rock sample preparation and assay methods. The method comprises the steps that firstly, a cylindrical rock sample is manufactured, an SHPB device is used for conducting impact pre-damage on the cylindrical rock sample at an air pressure value lowered than the critical air pressure, corresponding stress waves are recorded, and the dynamic strain peak value, the strain rate peak value and the unit volume absorbing energy are acquired through calculation; secondly, the circle center of the end face of the rock sample serves as a center point, and axial drilling is conducted to form a cylindrical standard damage sample; thirdly, macro and microscomic testing of CT scanning, nuclear magnetic resonance, a longitudinal wave speed, a permeability coefficient, elasticity modulus, uniaxial compression strength and the like is conducted on the standard damage rock sample; fourthly, the same macro and microscomic testing is conducted on standard complete rock samples with the same rock character and physical parameters; fifthly, the dynamic damage degree of the impact to the rock material is quantitatively judged with the dynamic strain peak value, the strain rate peak value, the unit volume absorbing energy and other impact effect parameters as the bases by combining the data of the macro and microscomic testing. The method has the advantages that operation is easy, and the test data are comprehensive and reliable.

Description

technical field [0001] The invention relates to a method for preparing and measuring a damaged rock sample, in particular to a method for preparing and measuring a rock sample for impact damage based on a SHPB test. Background technique [0002] A large amount of excavation construction is often involved in underground rock mass engineering. Traditional drilling and blasting and mechanical impact excavation using modern equipment such as fully mechanized excavators and TBMs are commonly used methods. Explosion / mechanical impact during excavation construction will cause dynamic disturbance and damage to the surrounding rock mass that the project intends to retain, resulting in deterioration of physical and mechanical properties of the surrounding rock. Therefore, the dynamic damage of surrounding rock caused by impact disturbance is a non-negligible threat to the long-term safety and stability of underground engineering. [0003] At the engineering site, the longitudinal wav...

AI Technical Summary

Problems solved by technology

[0007] Technical problem: The purpose of the present invention is to address the problems existing in the prior art, to provide a method for the preparation and measurement of impact-damaged rock samples based on the SHPB test, and to solve the problem that rock dynamic damage caused by impact cannot be accurately quantified

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