A Tunnel Model Test Method with Variable Rigidity of Lining Structure Joints

Abstract

A tunnel model test method with the changeable rigidity of a lining structure joint includes the steps that A, a shield tunnel model (1) is manufactured through gypsum, and a groove (2) for simulating the initial rigidity of a segment joint is formed in the periphery of the shield tunnel model (1); B, strain gauges (3) or displacement meters are arranged on the two sides of the groove (2); C, loading is gradually conducted on the shield tunnel model, corresponding groove depths are calculated according to different loads of all stages, and the depth of the groove (2) at each stage is made equal to the calculation value of the groove through the method that the etched position is marked through marks and gypsum dissolution agents are injected into the groove (2). According to the method, the rigidity of the lining structure joint can correspondingly change according to the change of the loads in the tunnel model test process, the method can better conform to mechanical behaviors of the tunnel joint in the actual project, and therefore test data of the method are more accurate and more reliable, and the accurate and reliable test basis can be provided for design, construction and maintenance of the tunnel project.

Description

technical field [0001] The invention relates to a tunnel model test method with variable stiffness of lining structure joints Background technique [0002] In tunnel engineering, the actual engineering and structural prototypes are generally large and complex, and their mechanical properties and stress mechanism cannot be obtained through direct research on the structure. Instead, model tests must be used, that is, with the help of models, tests are carried out according to the similarity principle and similarity criterion, so as to obtain various data and performance of the structure, and provide test basis for the design and construction of the tunnel. In the construction of the tunnel structure, there are joints due to the structure and construction technology. There are many ways to connect the tunnel joints, such as bolted joints, joints without connectors, plug-in joints, pin-insert joints and some other connection forms. . Due to its structural characteristics, the ...

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Problems solved by technology

However, since the depth of the cutting groove cannot be changed with the load and other factors in the test, it cannot truly reflect the change of the mechanical properties of the tunnel joint during tunnel excavation and operation

[0006] However, the stiffness of tunnel joints in actual engineering changes with changes in the external environment such as loads. Therefore, the simulation of joint stiffness in the above method can only be aimed at a specific stress state of tunnel joints. The experimental stiffness Such mechanical properties cannot be changed with other factors such as load during the test, which is inconsistent with the mechanical behavior of the tunnel joint in the actual project, resulting in large errors and low reliability of the test results of these model test methods, which cannot be used for the design and construction of tunnel projects. Provide accurate and reliable test basis for maintenance and maintenance

At the same time, due to the fixed joint stiffness, the existing methods cannot study the influence of the joint stiffness on the overall deformation and stress state of the tunnel structure.

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