Refined Simulation Method for Uplifting Centrifuge Test of Underground Structures in Earthquake Liquefaction

Abstract

An elaborate simulation method for floating centrifugal machine test of an underground structure in seismic liquefaction is characterized in that a discrete particle model close to the underground structure is built, a continuous solid-phase soil body model away from the underground structure is built through the RKPM method, and a liquefied coupling framework of a fluid RKPM point and discrete particles and a liquefied coupling framework of the fluid RKPM point and a continuous solid-phase soil body RKPM point are built so that a discontinuous power contact problem between a discrete particle soil body and the underground structure in seismic liquefaction can be fine analyzed, the discrete particle simulation scale is effectively controlled to save simulation time, and the fluid boundary movement problem caused by moving of the underground structure is taken into consideration. Compared with an existing fluid and underground structure-near field discrete particle-far field continuous solid-phase soil body coupling method, the elaborate simulation method avoids the simulation interruption problem caused by fluid and far-field continuous solid-phase soil body mesh distortion in liquefaction large deformation.

Description

technical field [0001] The invention belongs to the field of geotechnical engineering research, and in particular relates to a refined simulation method for an underground structure floating centrifuge test in earthquake liquefaction. Background technique [0002] The saturated loose sandy soil foundation will liquefy under the action of earthquake load. Macroscopically, the pore water pressure in the soil increases, and the effective contact stress of the solid phase of the soil is zero. At this time, the soil properties are similar to fluids and lose shear resistance. strength. Earthquake liquefaction causes the following hazards: such as house tilting, foundation settlement, subway tunnel uplift, road subgrade slippage, etc. [0003] A typical case of severe damage to underground structures during large liquefaction deformations was the severe damage to the Daikai Subway Station in the Kobe Earthquake in 1995. After that, the seismic analysis and anti-seismic research of...

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Problems solved by technology

[0004] In order to overcome the shortcomings of the existing methods, the present invention is based on the coupling method of underground structure-near-field discrete particles-far-field continuous solid-phase soil and fluid, in finely simulating the seismic response of underground structures in liquefiable sandy soil During the centrifuge test, there is a problem of grid distortion causing simulation interruption, so the present invention uses the RKPM method (Reproducing Kernal Particle Method) in the gridless method to discretize the far-field continuous solid-phase soil region and the fluid equation, so that the far-field The continuous solid phase soil model is the same as the fluid and near-field discrete particles, which can be adapted to large deformation analysis of earthquake liquefaction. The present invention also constructs a coupling framework of fluid and discrete particles-continuous solid phase soil and underground structures. Based on the above work, it avoids the The Problem of Simulation Interruption Caused by Grid Distortion During Earthquake Liquefaction Large Deformation Simulation

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