Full-automatic, digital and large frozen soil direct shear apparatus

Abstract

The invention which belongs to the field of civil engineering equipment relates to a full-automatic, digital and large frozen soil direct shear apparatus. The large frozen soil direct shear apparatus which comprises a shear box, a refrigeration system of an upper shear box, a refrigeration system of a lower shear box, a vertical servo loading and monitoring system, a horizontal servo loading and monitoring system, and a measurement and control system is to determine the shear strength of the freeze-thaw interface of the frozen soil or determine the shear strength of full frozen soil and full thawy soil. The size of a frozen soil sample in the embodiment of the invention is 305mm*305mm*200mm, static force and a layered compacting method are adopted to prepare remolded soil samples of different initial water contents and dry densities for shear tests; temperature control systems of the upper shear box and the lower shear box are adjusted to control the temperatures of soils in the shearboxes to guarantee the shear plane to be superposed with the freeze-thaw interface of the frozen soil sample. The direct shear apparatus of the present invention solves problems that the difficulty of testing the shear strength of the freeze-thaw interface is large, the shear tests of coarse grain soil are difficult and the like and provides reasonable design parameters for civil engineering and traffic engineering in cold or highly cold regions.

Description

technical field [0001] The invention belongs to the field of civil engineering equipment, in particular to a fully automatic digital large-scale frozen soil direct shearing instrument. Background technique [0002] The Qinghai-Tibet Railway passes through many mountain-crossing sections, so there are also many subgrades on sloped sections. Correctly evaluating the stability of such subgrades is a prerequisite for ensuring the safe operation of the Qinghai-Tibet Railway, and providing geological parameters for evaluation and calculation is a necessary prerequisite for proposing reasonable and correct results . The investigation and analysis of the unstable natural slopes on the Qinghai-Tibet Plateau mainly focus on the freezing-thawing interface. [0003] At present, the direct shear instrument used in the direct shear test at home and abroad is generally composed of upper and lower shear boxes, a vertical force loading system, a horizontal force loading system, a device for...

AI Technical Summary

Problems solved by technology

However, the conventional shear cell cannot consider the temperature factor, nor can it measure the shear strength at the interface.

At the same time, due to the size limitation of the shear box, the conventional shear requires that the soil particle size in the sample must be smaller than the coarse sand level

Images