Numerical Study on Process of Breaking Rock with TBM Cutter in Different Cutting Orders

Abstract

In order to research the effect of different cutting orders on breaking mechanism of TBM cutters for the rock without joints, this paper established the simulation models of breaking rock three TBM cutters in simultaneous and sequential orders, which is based on the 2D discrete element method. A series of numerical experiments were designed and the whole process of production and propagation of crack and rock breaking was successfully simulated. The simulation results showed that the cutter order determines the breaking mode, which is carefully analyzed: The chipping stress under the sequential order is higher than simultaneous way. The chips are formed by the side cracks under the two loading modes, while the shape of the rock chip are different. The distribution of the principal stress contour is almost symmetrical in different cutting order. Finally, conclusions and future work are summarized.

Dynamic Indentation Characteristics for Various Spacings and Indentation Depths: A Study Based on Laboratory and Numerical Tests

“…To promote rock breakages in target rock, extensive laboratory and numerical studies have been conducted from a machinery point of view. Besides the indenter shape and size, the indentation rate, and the loading sequence, the spacing and penetration (indentation depth) are the main machinery factors that may affect rock breakages and cutting efficiency [11][12][13][14][15]. For instance, an optimal spacing of 76 mm was proposed by Gertsch et al in a laboratory study where a hard rock was tested [16].…”

Rock Fragmentation Characteristics by TBM Cutting and Efficiency under Bi-Lateral Confinement

“…On the other hand, other researchers suggested that the breaking occurs due to the interpenetration of tension cracks caused by neighboring disc cutters. The content of a study regarding the characteristics of rock fragments can be also divided into two subsections: the first concentrates on the interior of the rock (e.g., uniaxial compressive strength, regarding joint, moisture content, and other efficient factors [3][4][5][6][7][8]), and the second focuses on external factors including tool size, shape, and machine operating parameters [9][10][11][12][13][14][15][16].…”

Study of TBM cutterhead fatigue crack propagation life based on multi-degree of freedom coupling system dynamics

“…Rostami (2008) proposed the methods of cutterhead system design, and analyzed different factors influencing the cutterhead performance. Xia et al (2012) and Tang et al (2012) used the discrete element method to study the influence of cutter forces under various geological conditions and cutter spaces. Besides, Huo et al (2010Huo et al ( , 2011Huo et al ( , 2013 established the optimization design model of TBM cutter layout based on a stochastic layout pattern, and the structure of support ribs and mucking slots was processed.…”