Arch Structure Concept in Lightweight Fill Design

Construction of road embankment over soft soils can cause significant non uniform excessive settlements that contribute to uneven road surfaces. This is due to the properties of soft soil which have low shear strength, high water content and high compressibility. These properties of soil are quite difficult and challenging to work with. This research is focused on how to mitigate the non-uniform settlement of embankments on soft soil using an innovative arch structure concept design incorporating with the current construction method of expanded polystyrene (EPS) as lightweight fill material. EPS are lightweight fill materials which are low density, stable, inert, environmentally safe fill rigid mats for road construction. However, they are large bulky blocks and have high buoyancy characteristics which will be unstable when high water table arises. The arch structure design reduces the use of EPS block while achieving almost the same performance as the conventional design. Physical modelling is used in this research to analyse the performance of this conceptual arch structure using a test box, sandy soil as embankment and wooden blocks as EPS. The concept of arch structure is implemented by removing some of the blocks at the base and setting up three different layout arrangement of spacing and thickness of the blocks which are called mixed staggering (a), mixed staggering (b) and lateral staggering. The performance of the design was measured by analyzing the settlement of the three arrangement layouts. The settlement observed was monitored photographically and measured with markings labelled on the test box. It was found that the layouts of mixed staggering (b) have is proven to reduce the excessive non-uniform settlements compared to the lateral staggering and mixed staggering (a). Hence, this research has established a suitable design guide using a mixed staggering arch structure fill material which is light and strong to withstand heavy loading to reduce ground settlement

The behaviour of remolded Batu Pahat soft clay with different OCR values under cyclic loading

The Batu Pahat Soft Clay, (BPSC) of Universiti Tun Hussein Onn Malaysia, (UTHM) were low in shear strength, bearing capacity, and suffer large settlements when subjected to loading. They undergo varies of dynamic cyclic loadings during their design lifetime and the response was typically more complex, requiring engineers to investigate the dynamic behaviour of soils thoroughly in the laboratory. The objectives of this research were to simulate remolded Batu Pahat Soft Clay (RBPSC) samples with different σv’, to study the dynamic shear modulus, G and damping ratio, D of (RBPSC) under cyclic loading with different f, OCRs, σv’ and σc’ and to analyses the correlation between G and D of the (RBPSC) with the OCR values under cyclic loading. As result, the 100 x 50 mm of remoulded samples are succeed simulated by using large strain consolidation apparatus of 50, 80 and 100 kPa of pre consolidation stress, contain moisture ranging within 42 to 55%. The series of remolded consolidated undrained dynamic cyclic triaxial test were ran under OCR of 1, 2, 3.85 and 4. Hence, it could be concluded that the G decreased when increasing of f and OCRs subjected to increasing axial strain while the G corresponding to each σv’ increases slightly as the σv’ becomes higher. The D shows minor increased when increasing of the f, OCRs and σv’ when subjected to increasing axial strain. Thus, input of parameter G and D can be review as technical values to key design structure on top of soil layer

Review on Soil Improvement by Using Various Chemical Additives for Foundation

This work aimed to study the most effective chemical additives to increase the strength of the clay soil. The problem statement is to improve the soil strength to avoid failure in the ground. The chemical additives that be used are lime, cement, and fly ash. These chemical additives were commonly used to stabilize the soil and make the shear strength of the soil increase. The data taken was from the previous research, where the data was compared to get the most effective chemical additives to improve the soil stability and soil strength. The percentage of the chemical additive used in the soil mixture was 8% to 10%. The data from previous research was chosen based on the rate used of the chemical additive and the research was taken from Science Directed website only. Data were collected through 30 previous studies using clay and chemical additives such as cement, lime, and fly ash. The data for Plastic Limit, Liquid Limit, Plasticity Index, Optimum Moisture Content, Maximum Dry Density, and Unconfined Compressive Strength was taken by referring to the previous study. Then the data was listed in Microsoft Excel to generate the graph for comparison. All the data obtained are then compared to get which chemicals can increase the strength of the soil. The result of this study shows that the cement was the most effective chemical additive to improve the soil strength and to stabilize the soil than the lime and fly ash

Performance of Silica Gel as Moisture Removal from Mortar

Silica gels are widely used as a desiccant to protect the product from moisture damage, which has capacity to absorb moisture from surrounding at level of 100% based on its own weight. Due to this performance, an innovative approach has been taken by applying the silica gel as moisture absorbance from mortar layer. The main objective of this research is to study the performance of silica gel as moisture absorption material that mainly to reduce the surface moisture of tested mortar samples. A series of procedures for experimental work has been designed purposely for this study. Three mortar samples with size of 300mm x 300mm x 50mm were prepared accordingly for each of sample with water-cement ratio of 0.40, 0.45 and 0.50. Initially, mortar samples were ponded with three liters of fresh water for period of 24-hours, and excess water were removed once completed. Then, data of surface moisture of mortar samples together with weight of silica gel was measured and collected simultaneously every 30 minutes for 6 hours. Experimental study found that S3, mortar with w/c of 0.5 had experienced the highest reduction of surface moisture rate of 0.047%/min due to the presence of silica gel. Silica gel, G2 that placed at the mortar with w/c of 0.45 has the highest rate of absorption of 0.119gram/min. When the number of usage increases, the performance of silica gel reduces. Lastly, a relationship is determined that as the surface moisture of tested mortar samples decreases, the weight of silica gel increases. As for the conclusion, selected silica gel showed a potential to be applied as moisture removal material for mortar, which then prevents the growth of mould or fungi

Improvement of soft soil stiffness using geo-composite cellular mat

The highway construction over sub-grade consisting of problematic soils gives challenges to the engineer due to their weak geotechnical characteristic [1, 2, 3]; High water content, High compressibility, and Low bearing capacity

Artificial intelligence based direct torque control of induction motor drive system

In this project, a three-phase Induction motor (IM) under the direct torque control (DTC) technique is studied. IM is known for its simple engines and its self-starter feature but it always suffered a setback in the area of torque and speed control as it is a highly coupled nonlinear plant and proves to be most complex and expensive speed drive. The application of direct torque control (DTC) is beneficial for fast torque reaction in IM but provide high torque and ripples due to harmonic effects. Thus, the speed control of induction motor is important to achieve maximum torque and efficiency. The aim of this study is to improve tracking performance of the induction motor drive using artificial intelligence control system. A method for controlling induction motor drive is presented with Proportional-Integral (PI) controller and Artificial Neural Networks (ANNs) for performance comparison. MATLAB/SIMULINK software is used to develop a three-phase 2 pole-cage type induction motor model. Also the performances of the two controllers have been verified in terms of its speed and torque responses. The ANN is trained so that the speed of the drive tracks the reference speed. This study proved that the performance and dynamics of the induction motor are enhanced using ANN controller as compared with PI controller

Feasibility Study of River Bank Filtration (RBF) at Sg. Kampar, Perak Using Numerical Modelling Technology (Visual Modflow)

Water demand around a world was increased due to growth of population, economy and urbanization [1]. Malaysia as a developing country is not exception to have a problem in order to cater an adequate water demand. According to populations statistic in Malaysia [2], the total population is about 32.0 million peoples in year 2017. In year 2016, the total water supply was increased about 97.7 % compared to year 2015. The facts showed that increased of water demand in line with the increase of population [2]

Foundation Failures Mitigation under Expansive Clay by Using Granular Pile Anchor System

Expansive soils are found in typical areas in the world especially in arid and semi-arid regions. The problems associated with this type of soil drive geotechnical engineers to invent new technologies as remediation’s such as physical and chemical treatments. Innovative foundation techniques were also suggested for remedying the swell-shrink problems of the expansive soil. The granular pile anchor (GPA) is relatively a more favorable technique indebted to its cost-effective, easy and fast to assemble and most importantly was found to be more efficient in remedying the expansive soil. Despite the extensive studies on the expansive soil remedies, yet the granular pile anchor system requires more comprehensive and in-depth investigations. This study is aimed at developing a model with granular piles of various length and diameter extended to the stable zone to investigate the heave and uplift pressure in the expansive soil. For this purpose, experimental and numerical analysis were conducted in a small and in a full scale model respectively. A significant improvement was attained in heave reduction and an increment of uplift capacity. The findings also show that heave decreased significantly when the length and diameter of the GPA increases while the uplift capacity increased. However, it was noted that the extension of length to the stable zone resulted in insignificant changes. Therefore, it can be concluded that the maximum length of 6 m is the ideal length for GPA for this particular type of soil

Determination of baseflow quantity by using unmanned aerial vehicle (UAV) and Google Earth

Baseflow is most important in low-flow hydrological features [1]. It is a function of a large number of variables that include factors such as topography, geology, soil, vegetation, and climate. In many catchments, base flow is an important component of streamflow and, therefore, base flow separations have been widely studied and have a long history in science. Baseflow separation methods can be divided into two main groups: non-tracer-based and tracer- based separation methods of hydrology. Besides, the base flow is determined by fitting a unit hydrograph model with information from the recession limbs of the hydrograph and extrapolating it backward

Application of Groundwater Sampling and Insitu Tests Technology in Defining the Seawater Intrusion Into Coastal Aquifer System

Application of groundwater sampling and insitu tests technology is used to identify the subsurface hydrogeology characteristics of the seawater intrusion condition into coastal aquifer system. The subsurface hydrogeology characteristics studies involved identifying subsurface hydrogeology materials, effects of groundwater tables to the seasonal patterns and groundwater quality of the coastal aquifer. The studies will be providing information on the types of material in geology deposits and bedrocks. The types of aquifer in the study area can be identified after the material types of the subsurface hydrogeology have been determined