A Device for Accurately Controlling the Supporting Force of Excavation Face in Shield Model Test

Abstract

The invention discloses a device for accurately controlling the support force of the excavation surface of a shield model test, which is composed of a pressure transmission device, a pressure supply device and a pressure stabilization device. Before the start of the test, add liquid to the hydraulic tank, record the degree of liquid level in the pressure test tube, and measure the thrust on the pressure application plate through the stress measuring tool. Read the liquid level at different heights, and draw the liquid level height H-pressure F curve. At the beginning of the test, connect the device into the tunnel model, calculate the pressure to be applied in the test through the liquid level height H-pressure F curve, and apply the pressure by controlling the liquid level height H. During the test, the micro self-priming pump was turned on, and the inlet pipe of the micro self-priming pump was close to the water surface by controlling the liquid level lifting plate to ensure that the liquid level would not change, so as to keep the pressure constant. The device can keep the support force of the excavation surface constant, the support force does not change with the displacement of the excavation surface, the variable is single, and the analysis is convenient.

Description

technical field [0001] The invention relates to a stress loading device, in particular to a stress loading device for a shield tunnel model test. The invention can be applied in the model test of the stability of the excavation surface of the shield tunnel, and provides a device for accurately controlling the supporting force of the excavation surface. Background technique [0002] With the further enhancement of economic and technological strength, the development of urban underground tunnels has entered an important historical period. As one of the most commonly used tunnel construction methods at present, the shield method has been widely used in tunnel and underground engineering construction due to its advantages of economy, high efficiency and minimal impact on the surrounding environment. In the process of shield tunneling at home and abroad, due to the unreasonable control of the size of the support force of the tunnel excavation surface, accidents of large deformat...

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Problems solved by technology

[0008] 2. When the gas (hydraulic) pressure method is used for stress loading, during the displacement process of the excavation surface, the actual support force of the excavation surface is not only the pressure in the tunnel, but also the reaction force caused by the deformation of flexible materials such as latex film itself , this part is difficult to measure

[0009] 3. When the gas (hydraulic) pressure method is used for stress loading, the displacement of the excavation surface will lead to a decrease in the volume of the tunnel, which will cause a pressure change. This part of the pressure change cannot be accurately controlled

[0010] 4. The above two methods can only simulate the process of slowly reducing the support force from a sufficiently large support force on the excavation surface

It is impossible to simulate the process in which the support force of the excavation face is relatively small from the beginning

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