Numerical analysis in rock engineering

In land scarce Singapore, it is of utmost importance to utilize underground space for various purposes, such as underground rock caverns for oil storage and defense purposes. The aim of this study is to understand the fundamental rock failure mechanism, and to identify the influence of various parameters on the rock response under dynamic loadings. The discontinuous deformation analysis (DDA) programme and numerical computing programme MATLAB were applied in creating specified rock models and modeling the dynamic uniaxial compression test. With respect to rock strength and failure procedure, influence of both external factors and internal factors are taken into consideration. External factors consist of loading/unloading rate and loading duration. Internal factors describe the sample natural properties, such as friction angle, cohesion and pre-exisiting cracks. In the present study, simulation results have shown that rocks fail in seven typical patterns upon different situations. Three modes of crack coalescence, shear, tensile and mixed types, are observed. The measured stresses and displacements depend on both external and internal factors. Impacting load determines the peak and slope of stress-time and displacement-time curves. Presence of pre-existing cracks weakens the materials’ stiffness and adds to their deformability. As far as shear failure is concerned, cohesion plays a more important role than friction angle. But both of them contribute in controlling the uniaxial compressive strength (UCS) and brittleness of the sample. All the analysis results obtained are compared with past studies and explained by relating to those potential factors.Bachelor of Engineering (Civil