Testing device and method for simulating ground loss triggered by subway shield tunnel stratum cavity

Abstract

The invention discloses a testing device and method for simulating ground loss triggered by a subway shield tunnel stratum cavity. The testing device comprises a visual identification system, a model box system, a poly-chloramine sac (11), a first guide pipe (12) and a second guide pipe (21) which are communicated with the poly-chloramine sac (11), a container (17) corresponding to the second guide pipe (21), a resistance wire (13) arranged inside the poly-chloramine sac (11) and a heating control device (20) connected with the resistance wire, wherein the visual identification system comprises a real-time monitoring camera (1), a fixing support (2) and an acquisition and calculation module (3); the real-time monitoring camera (1) is used for shooting a video image of a monitoring interface; the video image is transmitted to the acquisition and calculation module (3) to be analyzed and calculated so as to obtain displacement data of an interest point; the testing device further comprises a purdah (4) for covering the whole testing device and light sources (5) fixed in position. According to the device, the sedimentation of each particle in the developing process can be monitored in real time.

Description

technical field [0001] The invention belongs to the technical field of underground engineering tests, and in particular relates to a test device and method for simulating formation losses caused by formation voids in subway shield tunnels. It can simulate the surface settlement and the subsequent stratum loss process caused by stratum voids caused by over-excavation in shield construction, providing a basis for construction and design optimization. Background technique [0002] Today, the subway has developed rapidly due to its advantages of economy, comfort, convenience, and speed, and the shield tunneling method, as the most effective method for subway construction, has also developed rapidly. After development, it has been basically sound, forming a complete set of sound technical theories. However, the disturbance of the surrounding stratum caused by the construction process, resulting in the release of stratum pressure and stratum deformation, still exists. These prob...

AI Technical Summary

Problems solved by technology

[0004] 1. At present, most of the research is still on the research of surface subsidence. There is no simple, accurate and intuitive method for monitoring the particle displacement in the stratum caused by stratum voids, so the relationship between the stratum loss and the deformation of the upper soil cannot be obtained. There is no effective experimental data for studying the mechanism of formation loss

[0005] 2. Due to the principle of the test, there are problems such as centrifugal field radial and tangential errors, particle size effects, boundary effects, etc., so that the experimental results deviate from the prototype and cannot accurately reflect the change process of formation loss

[0006] 3. Although there have been some simulations of formation loss, there are quite a lot of simulation problems, and the system is relatively scattered and messy, and a sound and effective system has not been formed.

And the test efficiency is not high

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