Investigation of Volumetric Block Proportion (VBP) Effect on Excavation-Induced Ground Response of Talus-like Rock Mass Based on DEM Simulations

Abstract

Due to the complexity of the talus-like rock mass with different values of volumetric block proportion (VPB), it is thus crucial to explore the VBP effect on the excavation-induced ground responses. We conduct a series of 2D DEM (discrete element method) simulations on a common circular tunnel excavation in the talus-like rock mass with different VBPs (0%, 15%, 50%, 85% and 100%). For each VBP, two support scenarios, i.e., unsupported and supported by a rigid lining, are considered. The micro characteristics of the excavation-induced ground responses, including the contact force, force chain, coordination number and shear-slip contact, and the stress distribution and ground settlement are elaborated in detail. Accordingly, three types of talus-like rock masses are identified as soil-, hybrid- and rock-types, corresponding to VBP = 0–15%, 50%, and 85–100%, respectively. It is found that the lining support is essential for maintaining the ground stability of a tunnel excavation in the soil- and hybrid-type talus-like rock masses while the backbones formed by rock blocks in the rock-type talus-like rock mass can provide a certain support for the surrounding ground. Our findings have important implications for optimizing the construction scheme of tunnel excavation in different types of talus-like rock masses.

Special Issue “Construction Materials and Other Related Materials: Basic Theory, Applied Technology and Advanced Research Methods”

“…The present study conducted by Wang et al [ 14 ] examines the impact of volumetric block proportion (VBP) on the ground reaction generated by excavation in rock masses resembling talus formations. This investigation employs two-dimensional discrete element method (DEM) simulations.…”

“…Drawing upon the fundamental principles of mechanics, this approach continually incorporates the most recent research discoveries from mechanics and related fields, enhancing the disciplinary knowledge reservoir and adeptly tackling engineering challenges. This Issue encompasses theoretical and applied research contributions, with a particular emphasis on fostering collaboration across other disciplines [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ].…”

“…A classification scheme was created based on the themes and areas of attention of the study publications. The 15 papers in this Special Issue were divided into four general categories: Multi-Phase Materials and Enhancers, which investigated the analysis and evaluation of mechanical properties and performance enhancement methods for various materials [ 2 , 3 , 5 , 9 ]; Geotechnical Mechanics and Soil Engineering, which examined topics like rock mechanics, swelling pressure–suction relationship, grout properties, and excavation-induced ground response [ 1 , 6 , 7 , 14 ]; Concrete Mechanics and Materials, which concentrated on the effects of organic matter components, constitutive relationships, and concrete strength [ 4 , 8 , 15 ]; (Hydro-mechanics, Groundwater, and Slope Stability, involving the study of the time-dependent effect of seepage force on hydraulic fracture initiation and the failure mechanism of slopes during heavy rainfall events [ 11 , 12 , 13 ]. …”

“…Geotechnical Mechanics and Soil Engineering, which examined topics like rock mechanics, swelling pressure–suction relationship, grout properties, and excavation-induced ground response [ 1 , 6 , 7 , 14 ];…”