A test device for simulating tunnel excavation process

Abstract

The invention discloses a test device for simulating the tunnel excavation process. The test device comprises a test box. A dial indicator rack is suspended on the top of the test box. An embedded body is embedded in the bottom of the test box. The test box is filled with a soil mass simulation material. The embedded body comprises a first tunnel excavation test body, a middle partition test body and a second tunnel excavation test body. The first tunnel excavation test body and the second tunnel excavation test body are of the same structure. The first tunnel excavation test body sequentially comprises a primary support simulation layer, a secondary lining simulation layer and a mountain simulation piece from outside to inside. The mountain simulation piece comprises a plurality of plates which are arranged in parallel and detachably connected. By means of the test device, ground surface deformation data can be collected, stress data of a middle partition, a primary support and a secondary lining is collected at the same time, the process of simulating mountain excavation is changed into the process of taking out the simulation piece in a layered mode piece by piece through the platy layered mountain simulation piece, detachment is convenient, and the contour left after detachment is smoother.

Description

technical field [0001] The invention belongs to the technical field of tunnel engineering, and in particular relates to a test device for simulating a tunnel excavation process. Background technique [0002] At present, using geotechnical similarity theory to carry out tunnel physical model test is an important means to study and analyze tunnel construction problems. [0003] The tunnel construction model test is mainly carried out in two ways: one is to excavate and support the filled soil after the filling in the test box is completed; the other is to embed the lining of the tunnel support in the soil in advance. body, and make the part of the tunnel to be excavated as a wooden or other material mold, install a handle on the mold, and pull out the wooden or other material mold during the simulated excavation process. Method 1 is easy to operate, but it is difficult to simulate the excavation process. It is easier to excavate the tunnel itself when the soil is relatively s...

AI Technical Summary

Problems solved by technology

Method 1 is easy to operate, but it is difficult to simulate the excavation process. It is easier to excavate the tunnel itself when the soil is relatively soft, but it is easy to cause the surrounding soil to collapse after excavation and before support, causing The test failed. When the soil is relatively hard, excavation is very difficult and labor-intensive, and the outline of the tunnel after excavation is uneven. It is very difficult to install the lining, or the lining is not in close contact with the soil after installation, and it is difficult to collect the lining. force data

Therefore, method 2 is more commonly used, but method 2 also has certain shortcomings. For the simulated excavation part of the pre-embedded wooden mold, firstly, the processing of the wooden mold is not mechanized enough, and the precision of the processed mold is not enough; Although the mold is generally equipped with handles and other devices for easy removal after the filling is compacted, it is very difficult to pull it out smoothly. There are many cases of test failures due to the inability to pull out the embedded parts

And the second method generally removes the embedded parts at one time, and fails to realize the gradual process simulation of tunnel excavation

[0004] At present, the main shortcomings of this type of tunnel model test are: in the test of simulating tunnel excavation, due to the difficulty of data collection, the simulation of initial support is often ignored, which is quite different from the real construction method; the operation window cannot be disassembled, making the test box The value of repeated use is greatly reduced; the test box is placed directly on the laboratory floor, and the flatness is not enough, which leads to errors in the test results; the molding of gypsum lining is generally made of steel mold or wood mold, which is expensive to manufacture and cannot complete special-shaped linings such as multi-arch tunnels pouring, and it is extremely difficult to realize the production of models with lining thickness less than 1cm

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