The present work shows the application of the Smoothed Particle Hydrodynamics (SPH) on non-Newtonian fluids for simulating the injection of a cementitious material into underground caves to reinforce the soil. In special, it presents two main improvements over the already established SPH formulation: an implicit time integration scheme to overcome the problem of impracticable small time step restriction in highly viscous fluid simulation, and the introduction of air ghost particles (AGP) to fix problems on the free-surface treatment. This project utilizes the Incompressible SPH (ISPH) as a basis for the implementation of such improvements, which guarantees a stable and accurate pressure distribution. We validate the proposed implicit time integration scheme with pipe flow simulations and the free-surface treatment with a simple hydrostatic problem. Also, dam break numerical simulations using the proposed method resulted in very good agreement with experimental data. At last, we demonstrate the potential of this method with the highly viscous vertical jet flow over a horizontal plate validation test, which shows a complex viscous coiling behavior.

1 Introduction

In the city of Mitake, Gifu, Japan, there was an abundant supply of mineral coal underground in the 20th century. Since it was considered a great opportunity to generate income, the authorities decided to explore it as much as possible, leaving behind the empty underground caves. As a result, the current buildings, roads and other infrastructures built over these underground caves are in serious danger of problems such as soil settlement and ground collapse.

In this context, the authorities have proposed to fill some of these underground caves with a cementitious material called kira, which promotes great fluidity and fast hardening. In collaboration with them, the authors intend to utilize the Smoothed Particle Hydrodynamics (SPH) to simulate the behavior of this fluid during the injection process. The present study will show some improvements on the SPH to address this simulation accurately.

This content is only available via PDF.
You can access this article if you purchase or spend a download.