Method and pressure chamber for measuring crack characteristics of damaged rock

Abstract

A method and a pressure chamber for measuring the crack characteristics of damaged rock are provided, wherein the method comprises the steps of: (1) the preparation of a rock test sample; (2) the mounting of the rock test sample: applying a rubber sleeve to the prepared test sample on which upper and lower water permeable conductive press plates and upper and lower waterproof gaskets are mounted previously, respectively, and then mounting the test sample in the pressure chamber so that the lower part of the test sample is flatly connected with the base of the pressure chamber while the upper part thereof is connected to a compression bar through a pressing cap; connecting a lead to the outside, and connecting upstream and downstream water pipes with water inlet and outlet pressure sensors, respectively; and finally, tightly connecting the outer cover of the pressure chamber with the base; (3) the application of a confining pressure and a back pressure: applying the confining pressure to 2-3 MPa according to the sealing requirements of the pressure chamber, so that a rubber film is tightly fitted in with the test sample; next, applying the back pressure of 1 MPa; (4) the hierarchical application of axial pressures: applying the axial pressures step by step according to the intensity of the rock test sample, and testing the stress-strain relationship of the rock under the axial pressure each time and the alternating-current impedance spectroscopy of the rock after the application of the axial pressure each time; and (5) the analysis of damage crack characteristics: analyzing the change law of the damage micro-cracks of the rock according to the characteristic parameters of impedance arcs on alternating-current impedance spectroscopy Nyquist curve. The method and the device are simple, clear in train of thought and convenient to operate.

Description

technical field [0001] The invention relates to the problem of rock mass stability in rock mechanics and engineering, in particular to a method and a pressure chamber for measuring the damage and crack characteristics of rocks in the stress process. Background technique [0002] As a brittle material, the failure process of rock is actually the process of internal crack generation, expansion, merging and penetration. The generation and expansion of micro-cracks in rocks are the main factors affecting the macroscopic deformation and failure of rocks. The measurement research of rock crack propagation process is of great significance to the research of rock crack model and the establishment of rock constitutive relationship, rock deformation and failure mechanism and rock engineering stability evaluation. [0003] Since the 1960s, people have begun to study the process of rock crack propagation, and then the optical microscopic observation method has been applied in the study...

AI Technical Summary

Problems solved by technology

However, due to the complexity of rock composition, structure, and loading environment, as well as the temporary limitations of test methods, the current intuitive understanding of the rock crack propagation process is far from sufficient.

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