Filter cake freezing device of slurry shield test system

Abstract

The invention discloses a filter cake freezing device of a slurry shield test system. In the filter cake freezing device, freezing pipes are distributed in a model box simulating a tunnel structure; the inlet ends of the freezing pipes are connected with a liquid nitrogen tank through connecting pipes; the outlet ends of the freezing pipes extend out of the model box; the inlet ends and the outlet ends of the freezing pipes are hermetically connected with the model box; the top wall of the model box is hermetically connected with a forcing pipe; one side of the model box is provided with a shield machine sleeve opening; the model box is filled with a soil body; a layer of foam is formed between the soil body and the wall of the model box; and a temperature sensor is embedded into the soil body. Due to the adoption of the device, the forming condition of a filter cake in the slurry shielding process can be simulated, the formed filter cake is frozen and cured, and the form and the structure of the filter cake can be conveniently observed and analyzed. The forming mechanism and the relation between the foaming mechanism and various driving parameters of the filter cake can be obtained, so that scientific and reliable test bases are provided for slurry shield construction and the design of a slurry shield machine.

Description

technical field [0001] The invention relates to a mud film freezing device of a mud water shield test system. Background technique [0002] The mud-water shield construction method is a special method in the construction of shield tunnels, which is especially suitable for the construction of tunnels on the seabed, rivers and cities. The mud-water shield construction method is to use pressurized mud water to form a layer of mud film on the soil of the excavation surface during the excavation process of the shield machine, and use the pressure generated by the mud film to keep the excavation surface in balance. This method is called mud-water pressure balance shield method, referred to as mud-water shield method. The core of the mud-water shield method is that the pressurized mud water forms an effective mud film on the excavation surface. An effective mud film must be able to balance the pressure on the excavation surface and ensure the normal excavation of the shield machin...

AI Technical Summary

Problems solved by technology

However, since the mud film is in front of the tunnel excavation, it is difficult to detect during the construction process; under the simulated conditions of the laboratory, although the mud film can be formed, when the soil is taken out and the mud film is to be observed, the soil will not and the simulation environment of the mud film no longer exists, and the structure and shape of the mud film have completely changed, and it is also difficult to effectively analyze and observe its shape and support effect

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