Triaxial test method for shear strength property of weak layer

Abstract

The invention relates to a triaxial test method for shear strength property of a weak layer, a test device adopts a triaxial shear instrument, and test purposes are realized through the specific test sample preparation method: (1) test sample preparation-1: cutting a soil column on an undisturbed soil sample containing the weak layer along an included angle of 45 degrees in the vertical direction; (2) test sample preparation-2: cutting the soil column into the stipulated diameter; (3) taking out of a test sample: leveling two ends by cutting according to the stipulated height and weighing; and taking remaining oil for determining water content; (4) test sample saturation; (5) testing; and (6) data analysis: taking normal stress sigma as horizontal coordinate, and taking shear stress tau as vertical coordinate; taking an inclination angle of a connected straight line of positive stress sigma n and failure shear stress tau n () obtained under different ambient pressure conditions as an internal friction angle phi, and taking intercept on a longitudinal axial on the straight line as cohesive strength C; and obtaining the test result. By adopting the special soil sample preparation method and the analysis method, the uniformity of the shear stress and strain on the weak layer can be ensured and the main problems during testing of a direct shear apparatus can be effectively solved.

Description

technical field [0001] The invention relates to a test method, in particular to a triaxial test method for the shear strength characteristics of a weak layer. Background technique [0002] Weak layers in geotechnical engineering are one of the most common causes of failure in geotechnical engineering. Mastering and understanding the shear mechanical strength characteristics of the weak layer is often the key to solving such problems. However, it is not a good solution to accurately test the shear mechanical strength of the weak layer of rock and soil materials. At present, the commonly used method at home and abroad is the direct shear test. However, there are several key problems in the direct shear test method. First, the position of the shear plane is forcibly controlled by the steel ring; second, the shear stress of the sample is not uniform along the shear plane; The strain is uneven; four. The drainage conditions cannot be controlled; five. The principal stress direc...

AI Technical Summary

Problems solved by technology

Unlike the steel ring of the direct shear instrument, there is only a layer of rubber film outside the soil sample during the triaxial test, and there will be no problem of uneven shear deformation

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