A hollow frozen soil test device and its application method

Abstract

The invention discloses a hollow frozen soil test apparatus and a using method of the apparatus. A pressure chamber is arranged on a base; the pressure chamber is internally and sequentially provided with a lower part cushion block, a sample lower cap ring, a hollow frozen soil sample, a sample upper cap ring, an upper part cushion block and a piston from bottom to top; the top of the pressure chamber is provided with a piston hole, and the piston passes through the piston hole and is contacted with the upper part cushion block; an internal adhesive film and an external adhesive film are closely contacted with the wall of the hollow frozen soil sample; a refrigerating medium is connected with a confining pressure control device by an internal pressure channel and an external pressure channel; a cooling liquid circulation channel is connected with a temperature control device; a temperature sensor is arranged in the refrigerating medium. After the radial temperature gradient of the hollow frozen soil sample reaches the test requirement and is stable, a compression test, a shear test and a creep test of the hollow frozen soil sample with the radial temperature gradient can be realized, so that basis is provided for the further research of the influence on the frozen soil strength and deformation caused by the temperature gradient; furthermore, the hollow frozen soil test apparatus is convenient to operate and low in price.

Description

technical field [0001] The invention relates to a hollow frozen soil test device and a use method thereof, in particular to a frozen soil test device under radial temperature gradient boundary conditions and a use method thereof. Background technique [0002] Permafrost is a special rock and soil layer with a temperature below 0°C and contains ice, which is extremely sensitive to changes in external temperature. At present, the research on frozen soil mainly focuses on the uniform temperature frozen soil, and a consensus has been obtained that the strength increases with the decrease of temperature. The temperature field of frozen soil in natural frozen soil areas (permafrost and seasonal frozen soil) subgrade engineering, pipeline engineering, artificial frozen soil (shaft excavation, foundation pit enclosure, subway communication channel, shield docking and access holes) has Certain non-uniformity (temperature gradient), following the non-uniform temperature frozen soil e...

AI Technical Summary

Problems solved by technology

The existing hollow torsional shear instrument test object is a hollow sample, but the control of non-uniform temperature cannot be realized

The existing invention application number is: 201310010431.1 public document "temperature gradient frozen soil uniaxial creep test device and its use method" and application number: 201310313643.7 public document "a two-dimensional temperature gradient frozen soil test device and its use method", which can realize vertical temperature gradient control and two-dimensional temperature gradient control of solid frozen soil samples respectively, but neither of them is specifically for hollow frozen soil samples, and cannot accurately test the mechanical properties of hollow frozen soil samples

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