Deep soil freeze-thaw process test system

Abstract

The invention relates to a testing system for deep soil freezing / thawing process, which is structurally characterized in that a temperature-controlled box is connected with an external cold bath; a high pressure-resistant organic glass cylinder is arranged on a temperature-controllable steel base; two small holes are formed in the base, one is connected with a water guide pipe, and the other is connected with a pressure adjusting pipe; a permeable stone, a piece of filter paper and a sample are sequentially arranged at the upper part of the lower base, and a temperature sensor is mounted in the sample; a temperature-controllable upper press head is arranged at the upper part of the sample; a line leading-out hole is formed in the upper press head, and is sealed through sealant after the line is lead out; the upper press head is connected with the transmission rod of a testing machine; a measuring cylinder is connected with the sample through the water guide pipe; and the measuring cylinder is arranged on a weighing sensor and fixed through a bracket. By adopting the testing system, the freezing / thawing process of the deep soil can be rather systematically researched, so as to obtain the frost heaving rate and the water absorbing / draining rate of the deep soil which is in different depths frozen under the different temperature gradients. The testing system provides the technical guarantee for the research in clarifying the action of the external load on the forming processes of the freezing soil and the frozen soil cold-formed structures, and the mutual action of the temperature, the moisture content and the pressure of the soil body in the process of freezing under the high-pressure action.

Description

technical field [0001] The invention relates to a test device for simulating the formation and thawing process of deep artificial frozen soil indoors. Using this device, the indoor simulation of the freezing and thawing process of deep soil can be realized, and the frost heaving rate, absorption and drainage rate of deep soil at different depths can be obtained when they are frozen under different temperature gradients. Provide technical support for clarifying the role of external loads in the formation of permafrost and permafrost cold structures, as well as the interaction between temperature, moisture and pressure when soil freezes under high pressure. Background technique [0002] The so-called deep soil refers to the fact that its physical and mechanical properties are quite different from the mechanical properties of the shallow surface soil in the current geotechnical engineering research due to the large depth of the formation, which cannot be determined by the exist...

AI Technical Summary

Problems solved by technology

Therefore, in the construction process of the freezing method, the strength of the frozen wall is the key factor affecting its smooth implementation. In this regard, many researches on the mechanical properties of deep frozen soil have been carried out, but these studies are all based on the assumption of continuum. From Starting from the analysis of the behavior of frozen soil after being stressed, using the stress-strain relationship obtained from the test, applying curve fitting or elastic theory, plastic theory and other theories to study the strength of deep frozen walls, in these studies, generally Ignore all the details of the contact characteristics between particles, and do not consider a series of changes in physical properties of the soil during the formation of frozen soil due to the deep ground pressure

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