Pseudo-triaxial pressure-maintaining loading device and method for carrying out pseudo-triaxial pressure-maintaining loading experiment by using pseudo-triaxial pressure-maintaining loading device

Abstract

A pseudo-triaxial pressure-maintaining loading device comprises a cylinder body (10), an upper piston rod (20), a lower piston rod (30) and an annular oil bag device (4), a hollow cavity, communicated up and down, of the cylinder body (10) sequentially comprises an upper cavity (11), an upper sealing cavity (12), a confining pressure cavity (13), a lower sealing cavity (14) and a lower cavity (15) from top to bottom, the annular oil bag device (4) is arranged in the confining pressure cavity (13), and when an annular inner cavity (410) of an annular oil bag is filled with a medium, the confining pressure cavity (13) is sealed by the upper sealing cavity (12) and the lower sealing cavity (14). The outer wall of the annular oil bag is attached to the inner wall of the confining pressure cavity (13), the fidelity sample (7) is arranged in a sample cavity defined by the lower end face of the upper piston rod (20), the upper end face of the lower piston rod (30) and the inner wall of the annular oil bag, and a plurality of testing devices are arranged in an annular inner cavity (410) of the annular oil bag. The pseudo-triaxial pressure-maintaining loading device can accommodate the fidelity sample (7) and perform a pressure-maintaining loading triaxial experiment on the fidelity sample through the annular oil bag device (4), the upper piston rod (20) and the lower piston rod (30), so that the accuracy and the reliability of experimental data are improved, and the rock mechanical behavior can be more truly researched and the rock mechanical property index can be more truly measured.

Description

technical field [0001] The invention relates to an experiment loading device, in particular to a loading device used for a rock pseudo-triaxial experiment. Background technique [0002] Rock triaxial compression experiment is an important means to study rock mechanical behavior and measure rock mechanical performance index. The traditional triaxial testing machine is to place the sampled and cut rock samples in the confining pressure cavity of the testing machine, wrap them with rubber sleeves, heat shrinkable tubes or silica gel, and then inject hydraulic oil to test different confining pressures. The rock samples measured under this condition basically have no pore pressure in the initial state, which is inconsistent with the real rock state underground. Even if the pore pressure can be restored by osmotic pressure, the rock sample has undergone irreversible changes during the change of pore pressure, which will have a great impact on its mechanical behavior. [0003] Th...

AI Technical Summary

Problems solved by technology

However, since the obtained fidelity core is generally placed in a tank filled with pressure-holding medium, the traditional triaxial testing machine cannot complete the pseudo triaxial loading experiment on the fidelity core in a fidelity state.

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