Wedge-shaped tooth double-plate plane strain mechanism for true triaxial cell

Abstract

The invention relates to a wedge-shaped tooth double-plate plane strain mechanism for a true triaxial cell. The true triaxial cell comprises a pressure chamber base plate, a pressure chamber top coverand an external barrel of pressure chamber; two sets of wedge-shaped tooth double-plate plane strain mechanisms are symmetrically arranged in the true triaxial cell; each wedge-shaped tooth double-plate plane strain mechanism comprises a wedge-shaped tooth steel frame plate, a wedge-shaped tooth polished rigid baffle, an unloading bolt, a loading bolt and a pressure box. According to the wedge-shaped tooth double-plate plane strain mechanism for the true triaxial cell, the wedge-shaped tooth double-plate plane strain mechanisms are arranged in a traditional three-dimensional independently loaded true triaxial cell, the horizontal pressed movement of the wedge-shaped tooth polished rigid baffle is competed through the dislocation of a first wedge-shaped tooth set of the wedge-shaped toothsteel frame plate and a second wedge-shaped tooth set of the wedge-shaped tooth polished rigid baffle. The structure and the existing true triaxial cell can be combined for performing plane strain test on a geotechnical material, so as to accurately and stably perform independent control and measurement on main stress along the plane strain direction, so that the strength and deformation characteristics of the geotechnical material under the condition of plane strain state can be acquired.

Description

technical field [0001] The invention belongs to the technical field of geotechnical engineering testing equipment, and relates to a device for testing soil mechanical properties under plane strain conditions in true triaxial test research, specifically a wedge-shaped double-plate plane strain mechanism of a true triaxial pressure chamber . Background technique [0002] In actual engineering, many engineering problems (such as deep foundation pits, retaining walls, high fill embankments, dams, tunnels) are in or approximately in a state of plane strain, and currently, for projects with plane strain problems, when designing, The selection of parameters is generally determined according to conventional triaxial or direct shear tests, without considering the constraints of the direction of the principal stress and the contribution of stress changes to the strength of the soil under the condition of plane strain. Therefore, determining the mechanical properties of the soil based...

AI Technical Summary

Problems solved by technology

The existing modification only satisfies the deformation condition, and since the rigid baffle is installed in the pressure chamber, its horizontal displacement cannot be regulated, so the σ cannot be adjusted during the consolidation stage of the sample. 2 Consolidation confining pressure is applied in the direction, so that the principal stress σ in the plane strain direction 2 In the consolidation stage, the consolidation stress is not reached, causing the soil to shear at the initial stage, σ 2 The principal stress in the direction is actually a small principal stress. With the continuous development of shear deformation, it gradually develops into a medium principal stress. At this time, the soil really enters the state of plane strain

It is because of this difference that existing instruments cannot fully simulate the plane strain state of soil in actual engineering

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