Self-feeding type frozen soil mechanical test system

Abstract

The embodiment of the invention provides a self-feeding type frozen soil mechanical testing system, and relates to the technical field of frozen soil testing equipment. The self-feeding type frozen soil mechanical test system comprises an outer pressure chamber for providing triaxial pressure, an inner pressure chamber for changing the total volume of a sample, a cold bath system for carrying out a unidirectional freezing test on the sample, an axial force sensor, a displacement sensor, a bending element test system, a temperature control test system, a CT test system and a self-feeding type data acquisition control system, and the self-feeding type data acquisition control system is connected with each test component and is used for acquiring data of each test component and automatically controlling the test process. The system can accurately simulate the natural freezing process of the sample, accurately test the change of the total volume and the microstructure in the shearing process of the sample, realize the dynamic characteristic test of the sample, and provide technical parameters for the design of frozen soil engineering.

Description

technical field [0001] The invention relates to the technical field of frozen soil testing equipment, in particular to a self-feeding frozen soil mechanics testing system. Background technique [0002] Frozen soil is widely distributed in my country, including permafrost and seasonal frozen soil, which account for 75% of my country's land area. Many large-scale projects are carried out in permafrost areas, such as the Harbin-Dalian High-speed Railway and the Qinghai-Tibet Railway. [0003] The key point in the testing of mechanical characteristics of frozen soil is that it is necessary to accurately simulate the changes in the stress field and temperature field encountered by the frozen soil through the indoor test system, so that the physical and mechanical parameters obtained can provide accurate and reliable technical parameters for the design of frozen soil engineering. . The most used equipment in the prior art is the triaxial test system for frozen soil. This system ...

AI Technical Summary

Problems solved by technology

In the prior art, the samples can be frozen through refrigerators, model boxes, etc. After reaching the set negative temperature, the samples are put into the triaxial test system. During this process, the samples are gradually frozen from various parts. However, the freezing of the rock and soil mass in the field often freezes gradually from the surface inward, that is, one-way freezing. The objective fact of one-way freezing is not considered in the existing dynamic triaxial tests of permafrost

In addition, in the mechanical test of frozen soil, the change of the soil structure cannot be monitored in real time. In the prior art, CT scans are mainly used, but the test results scanned during the loading process often have certain limitations.

The total volume change in the frozen soil mechanical test is only monitored by a circular sensor in the middle of the sample, which cannot reflect the total volume change of the frozen soil during the shearing process, and only a relative value can be obtained

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