Direct shear test data acquisition instrument for big visual model of reinforced earth

Abstract

The invention relates to a direct shear test data acquisition instrument for a big visual model of reinforced earth. The direct shear test data acquisition instrument comprises a vertical loading system, a horizontal loading system and a shear box, wherein the shear box comprises an upper shear box and a lower shear box which are both filled with packing; the horizontal loading system comprises a push-pull electromotor and a sliding balanced pushing rod, and a displacement sensor and a pressure sensor are mounted on the push-pull electromotor; one end of the sliding balanced pushing rod is connected with the push-pull electromotor, and the other end of the sliding balanced pushing rod is connected with the lower shear box; a counterforce device is mounted on one side, far away from the sliding balanced pushing rod, of the lower shear box and connected with the upper shear box; transparent tempered glass is arranged on one side wall of the upper shear box in the shear direction, and a digital video camera is mounted in front of the tempered glass; a geotechnical material spring clip is mounted at one end of the lower shear box. The direct shear test data acquisition instrument is convenient to use, small in test error, precise test data and convenient to widely promote and use.

Description

technical field [0001] The invention relates to a direct shear test device, in particular to a data acquisition instrument for a large-scale visualized direct shear test of reinforced soil. Background technique [0002] With the wide application of reinforced soil technology, it is urgent to accurately measure the shear strength of the reinforced soil direct shear interface. The direct shear test is a common method to measure the shear strength of the reinforced soil interface. The principle of the test is that according to Coulomb's law, the shear strength of the reinforcement-soil interface is proportional to the normal pressure on the shear plane. Although the direct shear test equipment has been developed in recent years, it still has the following deficiencies: [0003] (1) The size of the geotechnical box in the test instrument is generally relatively small, the test will be limited by the size effect of the indoor model, and the research on the interaction between th...

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Problems solved by technology

[0003] (1) The size of the geotechnical box in the test instrument is generally relatively small, the test will be limited by the size effect of the indoor model, and the research on the interaction between the reinforcement-soil interface will inevitably be affected by the boundary effect;

[0004] (2) The shear stress distribution on the shear plane is uneven, and the shear failure of the soil sample starts from the edge first, and stress concentration occurs at the edge

[0007] (5) Sand particles are easily embedded in the gap between the upper and lower shear boxes of the existing shear box, which makes the test result too large;

[0009] (7) Existing test equipment can only obtain the macroscopic mechanical response of the interfacial interaction between reinforcement and soil, but cannot ascertain the evolution law of the mesoscopic fabric of sand and soil at the interface during the interaction of reinforcement and soil, so it is also impossible to reveal the reinforcement from the granular medium level. The mesomechanical nature of soil interface interaction;

[0010] (8) There are also many defects in the reading, recording and processing of test data, which are prone to human errors and cannot obtain accurate test results

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