Centrifugal experimental simulation testing device for surface subsidence induced by city shield tunnel construction

Abstract

The invention belongs to the field of tunneling in geotechnical engineering and underground engineering, and particularly relates to a centrifugal experimental simulation testing device for surface subsidence induced by city shield tunnel construction. The testing device mainly comprises a model box, a small displacement meter bracket, a big displacement meter bracket, a tunnel excavation device, a linear variable differential transformer (LVDT) displacement meter and the like, wherein the model box is a hollow cuboid; the small displacement meter bracket and the big displacement meter bracket adjust the LVDT displacement meter along the horizontal direction and the vertical direction, so that the surface subsidence and the soil layer deformation can be measured; and the tunnel excavation device can simulate the soil body deformation caused by stratum loss by discharging a certain volume of water. Through the device, the deformation influence of the city shield tunnel construction on surrounding soil layer can be more conveniently, really and effectively simulated, so more real and accurate experimental data can be provided for tunnel design and construction, and high efficiency and safety of the city shield tunnel construction are guaranteed.

Description

technical field [0001] The invention belongs to the field of tunnel engineering in geotechnical and underground engineering, and in particular relates to a centrifugal test simulation test device for surface subsidence induced by urban shield tunnel construction. Background technique [0002] In recent years, the rapid improvement of my country's urbanization level has led to the rapid development of urban underground rail transit systems. Shield method tunnel construction is more and more widely used in the construction of underground railway because it can have a small impact on ground traffic. This construction method has become an important construction method in my country's urban underground rail transit system. However, during the construction of the tunnel, due to the limitations of geological conditions and construction technology, the imbalance between the support pressure of the shield machine pressure chamber and the formation soil and water pressure caused the m...

AI Technical Summary

Problems solved by technology

The numerical simulation method is relatively mature, but the main shortcomings are: (1) The physical and mechanical parameters of the soil have a great influence on the numerical simulation results. However, due to the limitations of testing equipment, it is difficult to obtain accurate soil parameters ; (2) The numerical simulation method is difficult to completely simulate the stress history and boundary conditions of the soil, resulting in deviations in the results

The shortcomings of the on-site monitoring method mainly include: (1) Due to the limitations of instruments and equipment and human observation factors, the on-site results have certain deviations; (2) The pre-embedded test components on site are difficult to protect and are very easy to be damaged during construction, resulting in delays Monitoring; (3) On-site monitoring requires a lot of manpower, material and financial resources, especially for the long-term soil settlement monitoring caused by tunnel construction, which is more difficult to implement and has poor timeliness

The biggest shortcoming of indoor general physical model test is that it cannot reproduce the initial stress state of the field soil layer under the real gravity state. As an advanced physical simulation method, geotechnical centrifugal test can reproduce the prototype stress state by applying appropriate centrifugal force, which is very suitable. Mechanism studies in geotechnical and subsurface engineering, making it one of the preferred methods for studying the problem

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