Simulation of rock fragmentation induced by a tunnel boring machine disk cutter

Huiyun Li,Erxia Du

doi:10.1177/1687814016651557

Abstract

A constitutive model based on the Johnson–Cook material model and the extended Drucker–Prager strength criterion was implemented in LS-DYNA to simulate the rock failure process induced by a single disk cutter of a tunnel boring machine. The normal, rolling, and side forces were determined by numerical tests. The simulation results showed that the normal and rolling forces increased with increasing penetration while the side force changed little. The normal force also increased under the conditions of confining pressures. The damage region of rock and cutting forces were also obtained by simulation of two disk cutters acting in tandem with different cutting spacings. The optimum ratio of cutter spacing to penetration depth determined from numerical modeling agrees well with that obtained by linear cutting machine tests. The average normal and rolling forces acting on the first cutter are slightly greater than those acting on the second when the cutting disk spacing is relatively small. The numerical modeling was verified to accurately capture the fragmentation of rock induced by disk cutter.

Highlights

Tunnel boring machines (TBMs) have been widely used in tunnel construction for a variety of purposes such as highways and subways
The different forces acting on the two tandem cutting disks for the more closely spaced configurations are owing to the fact that the first cutter causes some damage to the rock, and the relatively close spacing results in reduced forces acting on the second cutter
The previous studies are mainly focused on the 2D numerical modeling of the rock fragmentation based on the discrete element method (DEM) and the finite element method (FEM)

Summary

Introduction

Tunnel boring machines (TBMs) have been widely used in tunnel construction for a variety of purposes such as highways and subways. Keywords Tunnel boring machine disk cutter, rock, material model, cutting force, fragmentation The Mohr–Coulomb and Drucker–Prager failure criterion have typically been utilized for modeling rock materials in the numerical simulation of the rock-cutting process, they considered only the influence of static stress.

Results

Conclusion