Shear test apparatus and shear test method of soil body under confining pressure status

Abstract

The invention discloses a shear test apparatus and a shear test method of a soil body under confining pressure status. The shear test apparatus includes: a shear fixture for clamping a to-be-tested soil sample, a pressurizing apparatus for applying confining pressure to the to-be-tested soil sample, and a vertical loading apparatus above the shear fixture. The shear fixture comprises an upper fixture and a lower fixture; the pressurizing apparatus includes four pressurizing pieces. The shear test method includes the steps of: 1) sampling; 2) shear test and acquisition of a soil body micro-structure image: clamping the pressurizing apparatus and the soil sample, performing the shear test, dropwise adding a curing liquid, level-cutting the bottom of the soil sample, supporting the soil sample, level-cutting the top of the soil sample, taking the soil sample out from a shear seam, subsequently processing the soil sample in the shear seam, and performing electron microscope scanning. The method has reasonable design and is convenient to carry out, is low in cost, is short in time, has good use effects and can easily and quickly complete the shear test of the soil sample for a soil body shear zone under confining pressure status, and also can accurately analyze the micro-structure of the soil body under the confining pressure status.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering, in particular to a soil shear test device and a shear test method under confining pressure. Background technique [0002] In recent years, the transformation of the natural environment by human activities has become more and more intense. Human engineering activities have caused many geological disasters, which have caused great damage to people's lives and properties. Among them, the slope instability induced by human activities is the most serious, and the focus of the study of slope instability is to study the deformation and expansion process of the soil shear zone. The shear zone refers to a strong deformation zone with shear strain developed in the lithosphere or soil mass, and the shear zone developed in the soil mass is a soil shear zone. This deformation zone can be a planar structure (fault) with strain discontinuity, or a ductile shear zone with continuous strain whe...

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Problems solved by technology

[0003] At present, when conducting shear tests on soil shear zones, the test methods mainly include CT visual scanning method, triaxial test and digital observation method, etc., and the corresponding test instruments mainly include direct shear instrument, triaxial Compression test devices and tensile instruments, etc., but the above test methods and test devices can only solve the local problems of the internal shear zone of rock and soil, and all have complex structures, high test costs, cumbersome test procedures, and operability to varying degrees. The most important thing is that the soil microstructure of the shear zone cannot be analyzed easily, quickly and accurately, so that the influence of the soil microstructure on the macroscopic performance of the soil shear zone cannot be understood. , the link between the soil microstructural properties of the soil shear zone and its macroscopic behavior cannot be established

In addition, it should be noted that most of the existing shear test devices cannot provide confining pressure during the shear test, and cannot better simulate the stress state of the soil

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