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Brazilian test which also known as indirect tensile test is widely used to evaluate the tensile strength of rock. Discrete element method (DEM) together with finite element method (FEM) approach was used to investigate numerically the response of granite material under Brazilian test for indirect measurement of tensile strength of rocks. The calibration analysis performed in this study using the commercial software LS-DYNA. It has been attempted to calibrate the micro-parameters in bonded particle model of granite rock for numerical modelling. In hybrid DEM-FEM simulation, the rock specimen was modelled in DEM while the steel plates were simulated using FEM. This numerical analysis is compared to experimental data of Brazilian test. It shows that the combination of numerical methods simulation could reproduce the trends of experimentally observed stress-strain curve of granite rock under tensile loading. Besides that, the hybrid DEM-FEM simulation also shows the same failure mode of granite specimen. Comparison between experimental data and numerical analyses is presented and discussed.

Groundwater contamination is crucial, particularly due to hydrocarbon liquid leakages. Additionally, the vibration impact affects the migration of hydrocarbon through the subsurface soil to the groundwater surface which is causes by the dynamic stress that is imposed on the soils. Therefore, this paper presents the investigation and discussions on the penetration of Light Non-Aqueous Phase Liquid (LNAPL) in vibrated unsaturated double-porosity laterite soil with 30% moisture content. The apparatus used for this experiment are a vibrating table, acrylic soil column, mirror, LNAPL and a Nikon D90 digital camera. The LNAPL migration pattern in laterite soil was monitored and recorded using a digital image processing technique (DIPT) at certain time intervals. The images were processed using Surfer software and Matlab routine to plot the LNAPL hue-saturation-intensity (HSI) values. As a result, the migration rate of LNAPL decreased with the impact of vibration towards the soil due to the rearrangement and porosity of the soil structure and this was found to affect the speed of liquid penetration.

Groundwater contaminations due to hydrocarbon or organic solvent spills in saturated or unsaturated zones affect the water resources. The quantity of hydrocarbon spills in the groundwater might influence the hydrocarbon migration. In addition, the soil moisture content in influencing the rate of migration is also unknown. Therefore, this paper presents the investigation migration of Light Non-Aqueous Phase Liquid (LNAPL) in unsaturated laterite soil with two dissimilar moisture contents and different of LNAPL volume. These lab-scale studies discuss the results of migration phenomena by employing image analysis by using soil column, mirror, LNAPL, and Nikon D90 digital camera. Aggregated soil was poured and compressed in an acrylic column until 100 mm height. Then LNAPL was poured onto the soil column surface instantaneously. The LNAPL migration pattern in laterite soil was monitored and recorded using digital image processing technique (DIPT) at certain time intervals then were processed with Surfer software and Matlab routine for plotting the LNAPL migration pattern. As a result, the analysis displayed the higher rate migration of LNAPL with high moisture content and bigger amount of LNAPL volume. However, the rates of LNAPL migration decrease with lower moisture content and small amount of LNAPL volume. The migration time required to reach bottom of soil was longer for low moisture content with smaller amount of LNAPL volume as compared to the high moisture content with bigger amount of LNAPL volume.