Study on Evolution Mechanism of Structure-Type Rockburst: Insights from Discrete Element Modeling

Abstract

Taking the “11.28” rockburst occurred in the Jinping II Hydropower Station as the engineering background, the evolution mechanism of structure-type rockburst was studied in detail based on the particle flow code. The results indicate that the failure mechanism of structure-type rockburst includes a tensile fracture induced by tangential compressive stress and a shear fracture caused by shear stress due to overburdened loadings and shear slip on the structural plane. In addition, it is found that the differences between structure-type rockburst and strainburst mainly include (a) the distribution of the local concentrated stress zone after excavation, (b) the evolution mechanism, and (c) the failure locations. Finally, the influence of four factors on the structure-type rockburst are explored. The results show that (1) when the friction coefficient is greater than 0.5, the effect of structural plane is weakened, and the rock near excavation tends to be intact, the structural-type rockburst intensity decreases; (2) the dissipated and radiated energy in structural-type rockburst reduces with rockmass heterogeneity m; (3) the lateral pressure coefficient has a significant effect on the intensity of deep rock failure, specifically in the form of the rapid growth in dissipative energy; (4) and the structural-type rockburst is more pronounced at a structural plane length near 90 mm.

The Evaluation of Rock Mass Characteristics against Seepage for Sustainable Infrastructure Development

“…They have proposed treatment methods for the rock mass fractures to make them more durable/sustainable against the effects of seepage. Hydraulic conductivity validation in rock mass fractures in mining technology has also been experimentally and numerically modeled by various researchers in the past [6][7][8][9][10]. Table 1 shows few noticeable correlations established between hydraulic conductivity and RQD.…”

“…There are several external factors of rock mass such as location, geological formation, and type of infrastructure. Various infrastructures cause stress removal caused by excavation, fracture filing due to a water reservoir, fluid injection due to hydro-fracturing, and associated activities (oil and water), causing stress changes in rock fault, etc., which affect its behavior [8,10,[23][24][25][26][27][28]. Literature reported the typical ranges of internal and external factors of rock mass.…”