Convergence Study for Rock Unconfined Compression Test Using Discrete Element Method

Mesh convergence is a vital issue that needs to be addressed in a numerical model. This study investigated the effects of mesh element number on the Discrete Element Method (DEM) to granite rock response under compression loading. This study used the 3D finite-element code LS-DYNA to model the Unconfined Compression Test (UCT) numerical simulation. Models with five different mesh types were conducted for convergence mesh, namely normal mesh, fine mesh, super fine mesh, coarse mesh, and super coarse mesh. The mesh convergence of rock media has been conducted using DEM and steel plates simulated using the Finite Element Method (FEM). The DEM-FEM numerical analysis is compared with the results obtained from the experimental test. The best mesh was obtained as the simulation could reproduce the stress-strain curve trends, the failure behaviour and compression strength observed in the experimental test. The normal mesh was selected as the best mesh type in this study based on the comparisons that have been made. This study shows that the DEM-FEM numerical simulation can represent granite rock and can be used for further study based on mesh convergence

The roles of statistics on Twitter in improving footballers performance / Muhammad Shahrin Aizat Noorshahrizam…[et.al]

Statistics on Twitter can holds considerable potential in exposing footballer’s performance. In exposing footballers performance to the public, social media like Twitter can be a very good platform on it because it delivers direct statistics and current performance of the players to the public especially for football fans. The use of statistics of Twitter can improving the footballers performance by exposing them their real match statistics so that they can do a change on which technique that they are weak to perform much better in the next game. The goal of this research is to study the role of statistics on Twitter in improving footballer’s performance. This research is using the qualitative research method. An interview has been made to six informants to get the result of this research. All the informants are footballers from different background. The study found that the statistics on Twitter is helping in promoting footballers and helping them in improving their performance

Quarry blast evaluation system for rock fragmentation

Blasting produces energy to fragment the rock mass in mining, quarry and civil engineering projects. In mining and quarrying operation, blasting aims to extract the largest possible quantity of rock at minimum cost in the safest manner with minimum side effects such as ground vibration, flyrock and noise. Hence, blast design plays a vital role. Poor blast design is harmful to the surrounding and the desired rock fragmentation cannot be obtained. It affects the drilling and blasting cost as well as the efficiency of all the subsystems such as loading, hauling and crushing in mining operations. Therefore, this research aims to evaluate the significant parameters related to the blasting operation and establish a blast design model for better prediction of particle size of rock fragmentation. The study will focus on the granite quarry operation. Terrestrial and aerial survey technology namely Terrestrial Laser Scanning (TLS) and Unmanned Aerial Vehicle (UAV) respectively, are carried out during pre and post of the blasting for discontinuity mapping. Then the engineering properties of the rock are determined through the laboratory work. These properties are then utilised in Discrete Element Method (DEM) numerical simulation using Bonded Particle Method (BPM) and Particle Blast Method (PBM) to predict the blasting performance. Once the model is verified, the influencing parameters are further investigated through a series of parametric study on rock fragmentation. The parameters involved are burden, spacing, stemming, hole diameter, bench height and powder factor. The relationship between the spacing to burden (S/B) ratio, stemming to burden (T/B) ratio, burden to hole diameter (B/D) ratio, bench height to burden (BH/B) ratio and powder factor against the predict mean particle size (d50) and uniformity index (n) is studied. Furthermore, a machine learning algorithm is utilized to predict the d50, sieve size at 80% material passing (d80) and parameters n as the output product. MATLAB and RapidMiner software of machine learning algorithms with four different learnings, which are Linear Regression, Decision Tree, Random Forest and Support Vector Machine (SVM), are utilised in this study. Comparisons of the output predictions between the learning algorithms are conducted and the influential parameters for the predictions are identified. The results show that Random Forest learning is chosen as the best machine learning, since the results obtained show the highest R-squared value, with the lowest Root Mean Square Error (RMSE) value. The best R-squared and RMSE results for prediction of mean particle size are 0.85 and 0.046, respectively. In addition, the best R-Squared and RMSE results for prediction of uniformity index are 0.75 and 0.324, respectively. A quarry blast evaluation system for prediction of rock fragmentation was developed. The blast evaluation system and prediction for rock fragmentation developed is focused on open pit quarry but this also may be applicable to rock slope. The blasting evaluation system established in this study will be very beneficial to policymakers, practitioners and designers associated with quarry blasting for a safe quarry blasting operation. Hence this will help the engineer to make crucial decisions during the planning, design and operational stages of a quarry

Development of brick from mud flood: mechanical properties and morphology changes

After the flood event, there is lots of debris and muds were found along the affected area. Soil treatment is an alternative method used to utilize the mud flood to increase the strength of the material to produce bricks. In this study, a series of laboratory test was conducted to determine the optimum mixture stabilizer of nontraditional additives called “SH-85” to stabilize mud flood soil to form a brick. The mud flood soil sample was taken from Kuala Krai, Kelantan after the flood event. Basic test such as Atterberg limit test, specific gravity test, sieve and hydrometer were carried out to determine the physical properties of mud flood soils thus used for soil classification. Unconfined Compressive Strength (UCS) test was conducted for treated and untreated of mud flood soils which were used to assess the engineering properties of the stabilized soil. The proportions of stabilizer added were 3, 5, and 10% from the soil weight and tested at 0, 3 and 7 days curing periods. Based on the results, it was found that the used of stabilizer could increase the soil strength. To achieve minimum values of crushing strength for bricks 2750 kPa, additional 2% of sodium nitrate was added to soil with 10% of SH-85 and cured for 3 days at 105 °C temperature. Microstructure analyses were conducted using Energy-Dispersive XRay spectrometry (EDX) and field-emission scanning electron microscopy (FESEM) tests. FESEM results show that the void of untreated soil was filled by a new cementations product and show the presence of white colour lumps in treated soil. This finding indicates that the mixture of SH-85 stabilizer and sodium nitrate is suitable for the mud flood soil to become bricks for building construction

Sustainable use of plastic waste on laterite soil as stabilizer

Plastic has been widely used in many fields due to its lightweight, strength, durability, and capable of being moulded in any form. However, plastic pollution has become one of the major threats to the world since plastic waste is non-biodegradable and composed of higher toxic pollutants that may harm the environment significantly. Therefore, recycle and reuse of plastic waste can be one effective way to reduce the risk of plastic pollution. With the rapid growth of cities, one of the main constraints in the construction industry is the availability of land with allowable soil settlement and sufficient bearing capacity. Therefore, the engineers need to find alternative solutions to make use of the land area even though with weak soil properties. One of the effective and low-cost ways is to reinforce the soil strength using plastic waste. This research was conducted to study the effect of using plastic waste as soil reinforcement in laterite soil. Variations in compaction characteristics and unconfined compressive strength of laterite soil for different plastic waste content and dimension were investigated. The results obtained were compared with untreated laterite soil. The optimum percentage and dimension of plastic waste needed to increase the soil strength were obtained from the results. The soil strength reinforced with plastic waste can be reduced as the percentage and dimension of plastic waste exceed certain proportions and sizes

Investigation of light non-aqueous phase liquid penetration in double-porosity using physical experiment and computer simulation

Groundwater resources benefits to human activity for developing country. Groundwater contamination is crucial, particularly due to the amount of leakage and spillage of hydrocarbon liquids such as light non-aqueous phase liquids (LNAPLs), resulting in contaminated the groundwater and unsafe for domestic and agriculture activities. Penetration of hydrocarbon liquids into groundwater can be seen through double-porosity soil. Therefore, this paper investigates the penetration of LNAPLs in double-porosity soil using computer modelling to calibrate and validate from physical experiment data. These computer modelling and physical experiment studies discuss the pattern and rate of LNAPL penetrations by employing PetraSim commercial software and digital image processing technique (DIPT) by using acrylic glass cylinder, mirror and Nikon D90 digital camera. The LNAPL volume of 70 ml and 150 ml were poured instantaneously onto the surface of soil sample for calibration and validation purposes. The penetration pattern in double-porosity were monitored and recorded using digital camera at pre-determine time intervals. The images were processed using Surfer software and Matlab routine to plot the LNAPL penetration pattern. PetraSim simulation was used to calibrate and validate the penetration of LNAPL through double-porosity soil with physical experiment data. As a result, the PetraSim results valid with the physical experiment results. The Nash-Sutcliffe efficiency results more than 0.50 with percentage of differences for calibration and validation are 1.34% and 5.47% between physical experiment and PetraSim simulation. As a conclusion, PetraSim simulation can be used for further investigation on LNAPL penetration through subsurface soil