Numerical Simulation of the Interaction Between Normal Fault and Bedding Planes Using PFC: Fid-Bau Portal

Numerical Simulation of the Interaction Between Normal Fault and Bedding Planes Using PFC

Haeri, Hadi / Sarfarazi, Vahab / Fatehi Marji, Mohammad

The effects of dip angles and thicknesses of bedding layers at the interaction line in between the planes of a normal fault and bedding layers are numerically studied by a discrete element modelling technics. The calibration of the numerical method is accomplished by using an inverse-modelling approach. The laboratory results of Brazilian tensile tests may be used to measure the micro-mechanical parameters of the intact rocks. The shear test results are also performed on the rock joints to determine the micro-mechanical parameters of the bedding interfaces in the present simulation work. The numerical simulation of the shear behaviour of normal fault is performed by making box models with dimensions of 100 mm × 72 mm to represent the bedding layers with different dips and thicknesses. The bedding plane dip angles change from 0° to 165° with an increment of 15° and the thicknesses of these layers change from 6 mm to 12 mm with an increment of 6 mm. The shear testing conditions are exposed to these models to form the normal faults for the numerical modelling of the physical problem under a lateral pressure of 2 MPa. The numerical modelling results show that the shear cracks initiate from all of the bedding interfaces. In this numerical modelling, three major oriented parallel tensile bands are developed and one vertical tensile fracture also propagates through the shear band so that the model is failed. As the bedding layers’ dips are increased, the angle in between the shear bands and the bedding layers is decreased, and as the bedding thickness is decreased, the lengths of shear bands are increased. However, when the bedding angles are 120° and 135° the minimum shear strength of the model is occurred.