Modeling damage processes in laboratory tests at the Horonobe Underground Research Laboratory

朝比奈 大輔*; 青柳 和平; 津坂 仁和*; Houseworth, J.*; Birkholzer, J.*

Proceedings of 8th Asian Rock Mechanics Symposium (ARMS-8) (USB Flash Drive), 9 Pages, 2014/10

We present ongoing collaborative work applying a rigid-body-spring network (RBSN), a special type of lattice model, to simulate laboratory experiments conducted in the Horonobe Underground Research Laboratory (URL) in Japan. The Horonobe URL Project, which began in 2001, has developed a URL at a depth of about 350 m in a sedimentary rock called the Koetoi and Wakkanai formation. The basic capabilities of RBSN modeling are demonstrated through two standard laboratory tests: (1) split-cylinder (Brazilian) test; and (2) uniaxial compression test. Bulk material properties (i.e., Young's modulus, the strength parameters such as tensile strength, cohesion, and internal friction angle) estimated by the experiments are directly used for the mechanical parameters of springs. Tensorial representations of stress are obtained within the lattice elements and compared with Mohr-Coulomb failure criteria for fracture simulation. Agreement between the numerical and laboratory test results is good with respect to stress development, tensile/compressive strength, and fracture pattern, under the assumption of homogeneous systems using the RBSN model. The connection of hydraulically active fractures is also addressed for both of the simulation studies.