A Ring Shear Test Apparatus for Vertical Shear Surface

Abstract

The invention relates to a ring shear test instrument suitable for a vertical shear surface. The ring shear test instrument comprises a shear box, a lifting system, a power rotating system, a monitoring and controlling system and a frame. In the shear box, shear plates are evenly fixed to an annular bottom plate in the radial direction of the annular bottom plate, and a shear box outer cover is buckled to the annular bottom plate and the shear plates in a covering mode and is assembled and fixed to the annular bottom plate through guide bars and guide grooves; the shear box outer cover is connected with a rotating force arm of the power rotating system to transmit torque, a coupling shaft pressing plate is embedded in a center hole of a top plate of the shear box outer cover in a centered mode and is driven by the lifting system to conduct normal force loading, the annular bottom plate is embedded in a cylindrical supporting platform in a centered mode, and an inner cylindrical side face generated when the annular bottom plate drives the shear plates to conduct circular motion under the action of rotating torque is a vertical shear surface. The ring shear test instrument can ensure that shear displacement and shear stress on the shear surface are uniformly distributed, the thickness of the vertical shear surface is not limited, and thus a large ring shear test in the presence of large particulate matter is realized.

Description

technical field [0001] The invention relates to a ring shear tester, in particular to a ring shear tester suitable for vertical shear surfaces, and belongs to the technical field of geotechnical test devices. Background technique [0002] Direct shear instrument and simple shear instrument are geotechnical test instruments that were earlier used in the study of soil shear properties. However, the limitations of these two instruments are that they can neither realize large displacement soil shear tests nor keep the shear area constant during the test. It was not until the advent of the ring shear instrument that the above two difficulties were solved, and at the same time it was ensured that the sample could be sheared under continuous displacement conditions. [0003] The development of the ring shear instrument began in the 1920s. The design concept of the early ring shear instrument is relatively simple, and the function is relatively single. It is generally used to stud...

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Problems solved by technology

However, this feature will cause the following problems: the uniform angular velocity on the entire shear plane during the shearing process will cause different shear displacements on the shear plane along the radial direction, resulting in uneven distribution of shear stress

As a result, the shear surface thickness of this type of ring shear instrument is limited to a small value, so large particles are not allowed to exist in the test sample, but there are often many large-sized rocks in the actual landslide slide zone soil. It is difficult to simulate the actual mechanical properties of landslide soil in the ring shear test by the existing ring shear instrument

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