Circulation load application shearing instrument for observing mechanics characteristic of soil contact face and structural part

Abstract

The invention discloses a cyclic shear apparatus which belongs to mechanic characteristic testing equipment and is used for observing the mechanical characteristic of the contact surface between structural member and soil. The cyclic shear apparatus consists essentially of a soil container vehicle which is arranged inside a bracket, a normal boundary control unit, a data collecting system and a hydraulic loading and control system which is fixed on the bracket; the soil container vehicle is arranged on a horizontal track on the internal bottom surface of the bracket; testing soils are fully filled in the vehicle where a structural panel is horizontally arranged; the normal boundary control unit is arranged on the upper surface of the structural panel; furthermore, the soil container vehicle is provided with an organic glass window. The cyclic shear apparatus can lead the static and dynamic mechanical characteristic of the contact surface under complicated stresses to reappear; furthermore, the cyclic shear apparatus directly exerts normal boundary conditions on the contact surface and measures the deformation of the contact surface due to bearing force, thus improving the testing and measuring precision; digital photography is used for directly recording the microscopic phenomena of the soil gains such as microscopic state arranging, sliding of the gains along the long axis direction and along the structural surface, rotating of the gain, and crushing of the gains, etc. so as to facilitate the analysis; furthermore, the cyclic shear apparatus can further determine the distribution of relative displacement of the soil and structural member along the contact surface and the thickness of the contact surface.

Description

technical field [0001] The invention belongs to mechanical property testing equipment, in particular to a cyclic loading shear instrument for observing the mechanical properties of the contact surface between a structure part and the soil, which is used for reproducing and observing the static dynamic response of the contact surface between the soil and the structure. Background technique [0002] The main instruments for the static and dynamic characteristics of the contact surface between soil and structure are direct shear instrument, simple shear instrument, torsional shear instrument, dynamic triaxial instrument and resonance column instrument. Among them, the direct shear and simple shear contact surface test instruments are improved on the basis of the direct shear instrument and the simple shear instrument for studying the mechanical properties of soil, and are widely used in the test and research of the mechanical properties of the contact surface. [0003] In recen...

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Problems solved by technology

However, most of the existing test equipment is improved on the basis of soil static and dynamic characteristics test equipment (such as direct shear instrument, simple shear instrument, etc.), without fully considering the characteristics of the contact surface itself

For example, the normal stress is generally applied on the soil rather than directly on the contact surface itself, which causes difficulties in controlling the normal boundary conditions of the contact surface and errors in measuring the normal stress; for example, most of the existing contact surface tests It is limited to observe its shear characteristics, but ignores the non-negligible normal deformation of the contact surface and the coupling characteristics of the normal stress-strain relationship and the tangential stress-strain relationship. Therefore, it is required to reproduce the contact surface under a more complex stress path. In addition, the size of the existing contact surface test equipment is generally small, which is only suitable for fine-grained soil such as sandy soil, and it is difficult to simulate the monotonic or cyclic loading of the contact surface of coarse-grained soil with larger particle size and structural parts. The actual mechanical behavior under the conditions; although the mesoscopic and microscopic measurement technology of the contact surface has been initially applied, it has not yet reached maturity, especially in large equipment, it has not been widely used and well integrated

These defects obviously limit the research on the static and dynamic characteristics of the interface between soil and structure, especially the interface between coarse-grained soil and structure.

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