Testing device for rock-soil body under stress and seepage coupling action and methods

Abstract

The invention discloses a testing device for a rock-soil body under the stress and seepage coupling action and methods. The device comprises a base, a sample, a confining pressure system, a loading system, a seepage system and a deformation measuring system, wherein the base comprises a bottom plate, a rectangular support is arranged in the middle of the bottom plate, the sample is a square columnand is placed on the rectangular support, a vertical support is arranged on the periphery of the rectangular support, and an air bag storage cavity is arranged on one side, close to the sample, of the vertical support the confining pressure system comprises a first gas pipeline and a second gas pipeline; the loading system comprises a counterforce frame arranged above the sample, a vertical actuator is arranged at the lower end of the counterforce frame, and the tail end of the vertical actuator is connected to a loading box; the seepage system comprises a water inlet pipeline and a water outlet pipeline; and the deformation measuring system comprises a vertical electronic displacement meter and a horizontal electronic displacement meter. Different lateral pressures can be applied to thefront side, the right side, the left side and the right side of the sample, the confining pressure environment is stable, the precision is high, and the loading test of the rock-soil body under the dynamic and static stress and seepage coupling action can be realized.

Description

technical field [0001] The invention relates to the field of geotechnical engineering research, in particular to a test device and method for rock and soil under the coupled action of stress and seepage. Background technique [0002] In recent years, with the rapid development of engineering construction, engineering problems caused by excessive soil deformation have occurred from time to time. The academic and engineering circles have carried out a large number of experimental studies on soil deformation characteristics, mainly including triaxial tests, consolidation test, direct shear test, etc. Because it can simulate the natural force state of the soil to the greatest extent, the triaxial test is the most commonly used test method to study the deformation characteristics of the soil. However, the triaxial test also has the following disadvantages: [0003] ① Triaxial tests need to use saturated samples, and in engineering practice, the soil may be in a state of natur...

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Problems solved by technology

[0003] ① Triaxial tests need to use saturated samples, and in engineering practice, the soil may be in a state of natural water content, such as high-speed railway embankment bed with coarse-grained soil filling, and the test results using saturated samples cannot completely and accurately reflect the actual state of the soil. Mechanical and deformation properties;

[0004] ② Domestic triaxial instruments all use water as the confining pressure medium, resulting in large confining pressure errors along the height of the sample. For example, the confining pressure difference between the upper and lower surfaces of a large coarse-grained soil sample with a height of 0.6 m can reach 6 kPa;

[0005] ③At present, the large-scale dynamic and static triaxial instrument developed for coarse-grained soil uses a cylinder as the sample, and only a single confining pressure can be applied during the test, and the actual stress state of the soil cannot be applied completely and accurately;

[0006] ④The current triaxial test device cannot consider the soil mechanics and deformation characteristics under the action of seepage or even when seepage damage occurs

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