Compression penetration test numerical simulation method based on particle discrete element and lattice Boltzmann

Abstract

The invention discloses a compression penetration test numerical simulation method based on particle discrete elements and lattice Boltzmann, and the method comprises the following steps: S1, carrying out three-dimensional particle discrete element simulation of a sand rain method and a quasi-vibration compaction method, and preparing virtual compression samples with different relative densities; s2, applying axial pressure to the virtual compression sample step by step, and performing three-dimensional particle discrete element numerical simulation of a lateral confinement compression test to obtain a discrete element numerical model after compression stabilization under each stage of pressure; s3, respectively slicing the discrete element numerical model after pressure compression at each stage, processing a slice image, and establishing a corresponding pore structure model; and S4, carrying out lattice Boltzmann numerical simulation of seepage aiming at the established pore structure model. According to the invention, the defects of the existing indoor compression penetration test technology are overcome, the principle is simple, the implementation is convenient, the calculation efficiency is high, the application effect is good, and the feasibility and superiority of the compression penetration test numerical simulation method based on the particle discrete element and the lattice Boltzmann are verified.

Description

technical field [0001] The invention relates to the technical field of numerical simulation of rock-soil mass compression penetration tests, in particular to a numerical simulation method for compression penetration tests based on particle discrete elements and lattice Boltzmann. Background technique [0002] In the construction of highways, railways, municipalities, airports, and water conservancy projects, there are problems of seepage changes in geological bodies such as foundations, slopes, and tunnels caused by changes in external loads such as filling, excavation, and building construction. The settlement calculation after subgrade filling and excavation, the stability analysis of slope tunnels, etc., and the water environment evaluation have important theoretical and engineering significance. [0003] At present, some scholars have determined the compression deformation of broken rock mass, sandy soil, clay, etc. under different pressures and the permeability coeffici...

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Problems solved by technology

However, there are many deficiencies in this indoor compression penetration test, mainly including: (1) Due to the installation of piezometer tubes, the height-to-diameter ratio of the sample is too large, and the vertical compressive stress of the lower soil will obviously deviate when the axial pressure acts. (2) The axial pressure in the test process is applied by weights, and the instantaneous reduction of soil pores caused by the instantaneous loading of weights will generate an impact dynamic water pressure, which affects the Test results; (3) During the penetration test, since the side wall of the sample is a rigid boundary, concentrated seepage is likely to occur near the boundary, which affects the test results; (4) The test is time-consuming and it is difficult to gain insight into the internal microstructure of the sample The change of seepage field hinders further research on the mesoscopic mechanism of rock and soil compression deformation and permeability change during deformation

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