Confining pressure keeping system of rock triaxial creep testing machine

Abstract

The invention discloses a confining pressure keeping system of a rock triaxial creep testing machine. In the system, a hydraulic pump is connected with a motor, an oil tank is connected with the inlet opening of the hydraulic pump via an oil filter, a relief valve is arranged between the outlet opening of the hydraulic pump and the oil tank, a servo change valve is respectively connected with the oil tank, the hydraulic pump, a double-stroke pressure cylinder and a check valve, the double-stroke pressure cylinder is internally provided with a limit sensor and is connected with the check valve in turn, the check valve and the oil line of the check valve connected with a triaxial chamber are respectively provided with an accumulator, a pressure gage and a pressure sensor, and the triaxial chamber is connected with the hydraulic pump via a stop valve and is connected with the oil tank via the stop valve. The invention has simple and convenient oil charging / discharging operations, and can maintain the pressure in the triaxial chamber to be constant in a long term, thus greatly improving the testing precision and effectively prolonging the service life of a hydraulic element.

Description

technical field [0001] The invention relates to the technical field of rock mechanics tests, and more specifically relates to a confining pressure maintenance system for a rock triaxial creep testing machine, especially suitable for ensuring that the rock triaxial creep testing machine maintains a constant confining pressure. Background technique [0002] The triaxial creep test of rock is an important means to measure the long-term mechanical behavior of rock, and the test time usually can be as long as several months, and at most it can be several years. The creep test process usually involves multi-level differential stress (axial pressure minus confining pressure). During the application of stress at all levels, its value must be kept constant strictly to ensure reliable test data. Most of the current rock creep testing machines use hydraulic servo control to achieve constant pressure. [0003] Practice has proved that due to the relatively simple structure of the axial...

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Problems solved by technology

[0006] In order to overcome the shortcomings of poor pressure holding capacity and short service life of the confining pressure system of the existing rock triaxial creep testing machine, the purpose of the present invention is to provide a confining pressure maintaining system of the rock triaxial creep testing machine. Oil filling and oil draining are easy to operate, can keep the pressure in the triaxial chamber constant for a long time, greatly improve the test accuracy, and effectively prolong the test life of hydraulic components

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