Electric double-surface shear apparatus

Abstract

The invention relates to an electric double-surface shear apparatus.An upper shear box, a middle shear box and a lower shear box are arranged on a foundation base, a bearing plate is arranged on the upper end surface of the upper shear box, a pressurizing plate is arranged on the bearing plate, an A pull-pressure sensor is arranged on the pressurizing plate and connected with an extension bar of a perpendicular pressurizing electric cylinder, and a perpendicular displacement sensor is mounted on one balanced vertical column and is in contact with the pressurizing plate; the middle shear box is further connected with a B pull-pressure sensor which is connected with a horizontal pressurizing electric cylinder on a slide rail base, and a displacement infrared emitter is arranged on the middle shear box; a control cabinet is further arranged on the foundation base, controls travel adjustment of all electric cylinders and processes sensor date in real time; the apparatus can be used for shearing strength test of an undisturbed soil sample, a disturbed soil sample and a soft rock sample, the whole test process comprises sample installation, sample performance and sample collection after test, and sample mounting and dismounting operation is convenient.

Description

technical field [0001] The invention belongs to the field of rock and soil engineering, and in particular relates to an electric double-sided shearing instrument applied to rock and soil bodies. Background technique [0002] The shear strength of rock and soil refers to the ultimate ability of rock and soil to resist shear failure, and is one of the important mechanical indicators of rock and soil. A large number of engineering practices have shown that the destruction of retaining structures, the occurrence of various types of landslides, and the destruction of foundations of buildings (structures) are mostly shear failures. , construction and management have very important theoretical and practical significance. The test for determining the shear strength index of rock and soil is called the shear test of rock and soil. The test methods include indoor shear test and field shear test. Due to the clear stress conditions, easy repeatability and low cost of indoor test, it i...

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Problems solved by technology

The two kinds of direct shear instruments use a small circular shear box, and the stress concentration phenomenon is relatively serious during the test process, which affects the test results; the vertical load of the instrument is applied using a lever mechanism, which will occur to a greater extent after the weight is applied. The inclination of the instrument causes a large loss of the vertical load acting on the sample; the application of the horizontal shear force of the instrument uses a worm gear mechanism, which can only control the horizontal shear displacement, that is, to achieve a strain-controlled shear test, and cannot apply a constant shear force To determine the deformation law of the sample shear failure, and the sample can only be damaged along a single contact surface of the upper and lower shear boxes

[0004] The actual engineering situation shows that the damage of retaining structures, the occurrence of various types of landslides and the damage of foundations of buildings (structures) are not a flat shear plane, but more obvious shear zone damage occurs, so It is necessary to conduct a shear strength test on a shear band of a certain thickness, but there are few studies on the shear strength of the shear band at present, mainly due to the lack of a double-sided shear instrument that matches this research

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