Evaluation of Discharging Surplus Soils for Relative Stirred Deep Mixing Methods by MPS-CAE Analysis

Abstract

Most of the ground in Japan is soft, leading to great damage in the event of liquefaction. Various ground-improvement measures are being taken to suppress such damage. However, it is difficult to carry out ground-improvement work while checking the internal conditions of the ground during the construction. Therefore, a visible and measurable evaluation of the performance of the ground-improvement work was conducted in this study. The authors performed a simulation analysis of the relative stirred deep mixing method (RS-DMM), a kind of ground-improvement method, using a computer-aided engineering (CAE) analysis based on particle-based methods (PBMs). In the RS-DMM, the “displacement reduction type (DRT)” suppresses displacement during construction. Both the DRT and the normal type (NT) were simulated, and a visible and measurable evaluation was performed on the internal conditions during each construction, the quality of the improved body, and the displacement reduction performance. As an example of these results, it was possible to visually evaluate the discharge of surplus soil by the spiral rod attached to the stirring wing of the DRT. In addition, the authors succeeded in quantitatively showing that more surplus soil was discharged when the stirring wing of the DRT was used than when the stirring wing of the NT was used.

Soil Behavior Modeling by MPS-Cae Simulation

“…Computer-aided engineering (CAE) [4][5][6][7][8] refers to the technology that helps to simulate and analyze large-scale construction experiments from the various stages using the prototypes on a computer. These prototypes are created by CAD (computeraided design) and others, considering the surrounding conditions [4][5][6][7][8].…”

“…Computer-aided engineering (CAE) [4][5][6][7][8] refers to the technology that helps to simulate and analyze large-scale construction experiments from the various stages using the prototypes on a computer. These prototypes are created by CAD (computeraided design) and others, considering the surrounding conditions [4][5][6][7][8]. In the field of geotechnical engineering, CAE can be used to visualize the inside of the soil and the stress acting on the inside of the soil, and to understand experiments that would require huge costs and/or phenomena that would be difficult to reproduce.…”

“…In the MPS method, each differential operator (slope, divergence, and Laplacian) of the governing equation, as shown in Eq. (2), is discretized by a weighting function [1][2][3][4]. The weighting function depends on each particle interaction model's interparticle distance r and the influence radius (𝑅𝑅: 2.1 to 4.1 times the interparticle distance).…”

“…The sum of the weight functions in the support domain is commonly known as the particle number density (𝜎𝜎 𝑖𝑖 ) and it is defined as Eq. (4).…”

A Comprehensive Review of Sustainable Assessment and Innovation in Jet Grouting Technologies

“…The adoption of the Moving Particle Simulation (MPS) method with Computer Aided Engineering (CAE), that is MPS-CAE simulation in geotechnical engineering represents a significant step towards more sustainable construction practices [76][77][78][79][80][81][82][83][84][85][86]. In particular, Inazumi et al [14] innovatively applied MPS-CAE simulation to analyze and elucidate the intricate construction mechanisms underlying jet grouting technology.…”