Sample preparation device and method for tensile test of soil engineering and testing method

Abstract

The invention discloses a sample preparation device and method for tensile test of soil engineering and a testing method. The sample preparation device comprises a sample preparation mold, wherein anintermediate tensile section of the sample preparation mold and tensile fixtures at the two ends of the sample preparation mold are detachably connected. After the accurate compaction treatment is carried out on a test sample by adopting an improved layered compaction device, the intermediate tensile section of the sample preparation mold is dismantled, and the test sample, the two ends of which are clamped by the tensile fixtures, is obtained; and the tensile fixtures are connected to a testing machine, so that the tensile test of the test sample can be carried out. The sample preparation device for the tensile test of soil engineering is simple in structure and improves the precision of sample preparation and the convenience of testing.

Description

technical field [0001] The invention relates to a sample preparation device, method and test method for a geotechnical tensile test, belonging to the technical field of geotechnical tests. Background technique [0002] In the fields of hydraulic engineering and geotechnical engineering, the tensile strength index of soil is often not taken seriously, and there is no uniform test specification and test device for related test research and data measurement. However, a large number of engineering accidents show that the cracking and collapse of the soil, the hydraulic splitting of the core wall of the earth-rock dam, etc. are closely related to the tensile strength and tensile strain of the soil, so it is necessary and urgent to carry out in-depth research on the tensile strength of the soil of. [0003] The uniaxial tensile test that is widely used at present has the following problems: for regular cuboid and cylindrical samples, since the sample is fixed by the friction betw...

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Problems solved by technology

[0003] The uniaxial tensile test that is widely used at present has the following problems: for regular cuboid and cylindrical samples, since the sample is fixed by the friction between the clamp and the soil, the clamping force is too small, and the gap between the sample and the clamp It is easy to slip between the clamping force and the clamping force is too large, and the joint between the sample and the fixture is prone to extrusion deformation, which reduces the effective cross-section of the sample joint, thus forming an obvious weak surface; for samples with low density and high moisture content, The method of using epoxy resin to bond the sample and the test slider is no longer applicable; for the sample using the trapezoidal fixture, it can be found through finite element numerical simulation that there is an obvious stress concentration phenomenon at the connection between the trapezoidal fixture and the sample; For some large samples in special working conditions (such as gravel-mixed samples), improper delamination and compaction methods will often cause some weak surfaces in the sample (such as axial delamination compacted samples are extremely weak during the tensile test). easy to break at the delamination), which greatly reduces the reliability of the test results

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