Clay adhesion test device with upward soil pushing and extruding effect and adjustable contact area and test method

Abstract

The invention provides a clay adhesion test device with upward soil pushing and extruding effect and adjustable contact area and test method. The test device comprises a cylindrical soil box, an annular metal backing plate, a soil box cover plate, a fixed pulley block, a water storage bottle, a water supply bottle, a flowmeter, a balance, an air compressor, a water supply barrel, a pressure control valve, a pressure meter, a water bag, a valve, a hose and a nylon rope, wherein constant pressure is set by the air compressor and loaded to the water supply barrel, the water bag swells under the constant hydraulic pressure to produce an upward soil pushing and extruding effect, soil samples are loaded uniformly, and interfacial stress between the soil samples and the soil box cover plate is more uniform. The adhesion of the soil samples with different contact areas with the soil box cover plate is tested by replacing annular metal backing plates with different cross section areas, and by means of the annular metal backing plates, the problems about adhesion test under different contact areas and the soil samples adhering to the bottom surface of a test disc in an adhesion test are solved effectively.

Description

technical field [0001] The invention belongs to the technical field of tunnel and underground engineering test instruments, and in particular relates to a clay adhesion test device and a test method with adjustable contact area and upper pushing soil. Background technique [0002] Shield method construction is widely used in urban tunnel construction due to its fast excavation speed, high safety performance, easy settlement control, and small impact on the surrounding environment. Due to the complex underground geological conditions, the shield machine is constructed in a stratum rich in clay, and the crushed soil that is cut is easily bonded to the surface of the cutter head. Thick, eventually a mud cake is formed on the surface of the cutter head, which causes the cutting speed of the cutter head to drop sharply, and at the same time, the oil temperature of the cutter head is too high, which makes the shield unable to excavate, which greatly reduces the excavation efficien...

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Problems solved by technology

[0005] The object of the present invention is to provide a kind of clay adhesion test device and test method with adjustable contact area and push up soil, to solve the problem of cohesive soil and cohesive soil on the bottom surface and side of the test pan in the cohesive soil adhesion test model test. To solve the problem that the contact area with the metal test plate cannot be changed, determine the change law of the adhesion between the cohesive soil and the metal contact surface, which has the advantages of preventing the bottom and side of the test plate from sticking to the soil and adjusting the contact area between the soil sample and the test plate. Applied in the research field of revealing the mechanism of cohesive soil adhesion and the formation mechanism of cutterhead mud cake

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