Study on Meso-Material Parameters of Submarine Weathered Granite Based on Parallel Bond Model

Abstract

In order to study the mechanical properties of submarine weathered granite under marine geological conditions, uniaxial compression tests were carried out on the original medium weathered granite of the seafloor of an offshore area in Pingtan, Fujian Province by using triaxial experimental apparatus to analyze the fracture characteristics, stress–strain characteristics, and compressive strength indexes. Based on the theory of discontinuous medium, the uniaxial compression and uniaxial tensile tests of rocks were simulated, and the microscopic mechanical parameters of discrete elements of granite samples were determined based on the indoor macroscopic mechanical tests: effective modulus Et, compressive elastic modulus Ec, macro Poisson’s ratio μ, and uniaxial compressive strength σc. The results show that the parallel bond model has good simulation results for the uniaxial compression test, but the tensile strength and tensile–compression ratio were quite different from the experimental values. When the confining pressure is large, the calibrated parameter adaptability by uniaxial compression is poor. The reason for certain errors is a large resistance of the parallel bond model to particle rotation and the influence of normal stress on shear strength is not considered. The cementation model can be modified by adding coefficients based on laboratory test results.

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

“…In our model, we use the rolling resistance model [22,47] to reproduce the contacts between soil particles and rock blocks. Since the rock blocks may be crushed and broken under loading, the linear parallel bonding model is adopted to simulate this behavior by bonding the disks inside the polygons [22,[48][49][50][51].…”

“…Since the rock blocks may be crushed and broken under loading, the linear parallel bonding model is adopted to simulate this behavior by bonding the disks inside the polygons [22,[48][49][50][51]. We conducted a series of large-scale direct shear tests on the samples of taluslike rock mass, which were collected from the Tayi Tunnel of Jian-Ge-Yuan Highway Project in Yunnan province in the Southwestern China [9,31].…”