Constant-pressure self-circulation frost heaving test system

Abstract

The invention discloses a constant-pressure self-circulation frost heaving test system. The constant-pressure self-circulation frost heaving test system comprises a frost heaving test subsystem and awater pressure control subsystem, wherein the frost heaving test subsystem comprises a test box body and a controller module; a sample box for holding a soil sample is arranged in the box body; a temperature detecting device, a refrigerating device, a displacement detecting device and a pressure device are also arranged in the box body; a base is arranged in the test box body; a water holding reservoir is arranged on the base; the test box is put in the water holding reservoir; the bottom surface of the sample box is a porous backing plate with a certain thickness; the water pressure control subsystem comprises a water storing reservoir and an active water delivering pipe; the water storage reservoir supplies water to the water holding reservoir through a pipeline; the active water delivering device is used for delivering water into the water storage reservoir; a draining outlet is formed in the base; water exceeding a certain position in the water holding reservoir is drained from thedraining outlet. The constant-pressure self-circulation frost heaving test system disclosed by the invention can simulate a water absorption frost heaving deformation test of plain soil and saline soil under a low-temperature environment in a laboratory and can ensure constancy of water pressure and recycling of water for test in the testing process.

Description

technical field [0001] The invention belongs to the technical field of soil testing, in particular to a constant pressure self-circulation frost heaving test system. Background technique [0002] Soil heave and salt heave are volume expansion phenomena caused by water ice formation and salt crystal precipitation in soil. Engineering structures in permafrost and saline soil areas will be damaged due to frost heaving and salt heaving of the soil. Therefore, it is imperative to conduct in-depth research on the mechanism of soil frost heaving and salt heaving. [0003] The type of frost heaving test machine in the standard of soil engineering test methods (GB / T 50123-1999) is widely used in the determination of soil frost heave due to its simple structure, but this type of test machine also has obvious deficiencies. That is to say, the water supply system is a closed plastic pipe with a certain height. During the test, the water pressure will change with the change of the wate...

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Problems solved by technology

[0003] The type of frost heaving test machine in the standard of soil engineering test methods (GB / T 50123-1999) is widely used in the determination of soil frost heave due to its simple structure, but this type of test machine also has obvious deficiencies. That is to say, the water supply system is a closed plastic pipe with a certain height. During the test, the water pressure will change with the change of the water level, which will inevitably affect the test results. Facts have proved that when the water level in the plastic pipe is high, it is easy to cause water to flow around. overflow; if the water supply system is supplied by running water, the long test period will inevitably lead to waste of water resources, and it cannot be used for the test simulation of the groundwater as brine, so that it is impossible to carry out the saline soil frost heaving test research

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