Shield tunneling melting and ice-containing mud cake forming model test device and test method

Abstract

The invention provides a test device and a test method for a shield tunneling melting and ice-containing mud cake forming model. The device comprises a support frame, a bolt I, a motor, a rotating shaft, a bolt II, a ventilation pipe, a temperature control device, a cutter head, a heat preservation box, a metal box, frozen soil, a support platform and a spring. After being started, the motor drives the cutterhead to rotate through the rotating shaft; the temperature control device is connected with an external air conditioner air outlet through a ventilation pipe to achieve the purpose of controlling the external temperature of the frozen soil layer; the heat preservation box is arranged on the supporting platform, the bottom of the supporting platform is connected with the spring, the heat preservation box can be pushed upwards through the compression effect of the spring, and the cutter head can make complete contact with frozen soil. The initial compression amount of the spring determines the jacking force of the cutterhead. According to the device, by calculating the viscosity amount of frozen soil under different factors, the relationship between the adhesion amount of a soil body and the initial moisture content, freezing time, control temperature and tunneling parameters of the soil body is counted, and the melting condition caused by shield tunneling and the rule that ice-containing mud cakes adhere to the surface of a cutterhead are summarized.

Description

technical field [0001] The invention belongs to the field of shield tunnel construction, and particularly relates to a model test device and a test method for shield tunneling and thawing and formation of ice-containing mud cakes in permafrost layers. Background technique [0002] During the excavation process of the shield machine, the phenomenon of soil adhesion or clogging of the shield cutter head is often encountered. Adhesion is the attractive force generated by the adsorption of water molecules between the soil and the structure. During the cutting and extrusion process of the cutter head of the shield machine in the soil, it is easy to form a high-strength mud cake at the center of the cutter head, and gradually move towards the soil. The surrounding diffusion causes the cutter head and the cutter to be wrapped, and the soil layer cannot be effectively cut, which reduces the shield tunneling efficiency and greatly increases the construction period and construction co...

AI Technical Summary

Problems solved by technology

Existing test devices are mainly aimed at soils with different moisture contents to measure the adhesion between the metal interface and the soil. Not only is there a lack of research on the adhesion characteristics of frozen soils, but the related research is unable to actually solve the problems in the tunneling process of frozen soils. Encountered problems of tunneling melting and icy mudcake formation

[0004] Therefore, the existing technology cannot measure the melting caused by shield tunneling and the law of ice-containing mud cakes on the surface of the cutter head, let alone solve the problem of shield mud cakes in permafrost

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