Shield Excavation Surface Model and Simulation Method Applicable to Geotechnical Centrifugal Model Test

Abstract

The invention belongs to the field of geotechnical engineering and tunnel engineering, and discloses a shield excavation surface model and a simulation method suitable for geotechnical centrifugal model tests. The section of the model shield is close to the inner surface of the centrifugal model slot, so as to observe the excavation surface of the shield; one end of the model shield is a rigid plate with holes covered with latex film, which is used to simulate the shield cutterhead with a certain opening ratio and its The contact with the excavation surface stratum; the other end of the model shield is connected to the hydraulic pressurization system, which is used to provide the support force of the excavation surface. The lateral surface displacement of the stratum is measured by the pre-buried sensor; the support force of the excavation surface is tested by the pressure gauge; the change of the soil displacement vector field of the excavation surface is measured by the particle image velocimetry technology and the close-range photo-mapping system during the instability process of the excavation surface process. The invention makes the stress of the soil body on the excavation surface closer to the real situation, obtains a more real damage form of the excavation surface, and avoids the deformation of the excavation surface caused by the change of formation pressure during the acceleration process of the centrifuge.

Description

technical field [0001] The invention belongs to the field of geotechnical engineering and tunnel engineering, and in particular relates to a shield excavation surface model and a simulation method suitable for geotechnical centrifugal model tests. Background technique [0002] In the past 10 years, with the rapid development of social economy and urbanization, mud-water shield tunnel technology has become an indispensable key technology in the construction of major transportation and other infrastructure in my country. During the excavation process of shield tunneling, setting a reasonable support force on the excavation surface and ensuring the stability of the excavation surface become the key to safe construction. During the construction of large-scale mud-water shield tunnels in China, the mud-water shield often passes through important structures such as high water pressure and high permeability strata and embankments. When the support force of the excavation face is sm...

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Problems solved by technology

[0005] In order to overcome the deficiency that the actual stress and deformation of the excavation surface of the shield tunneling machine are quite different in the existing centrifugal model test, the present invention proposes a more realistic simulation of the contact form between the cutterhead of the shield tunneling machine and the soil on the excavation surface. Provide a more reasonable shield excavation face model and simulation method suitable for geotechnical centrifugal model

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