Evaluation and classification of potential sedimentary basins in Malaysia for carbon dioxide storage

The purpose of this study is to evaluate and classify potential sedimentary basins in Malaysia for carbon dioxide (CO2) storage that includes screening and ranking of potential sedimentary basins based on selected criteria by using parametric normalization, mapping of potential sedimentary basins by using ArcGIS, and finally estimation of theoretical storage capacity and anticipation of potential injection zone based on the basin stratigraphy of the highest potential area for CO2 sequestration. The screening and ranking of potential sedimentary basins was conducted quantitatively by assigning score and weight to each of the screening criteria and analyzed using Excel-based evaluation tools to rank the potential storage sites for CO2 sequestration in Malaysia. The mapping was conducted by using ArcGIS and revealed that 27% of the study area was classified as high potential area, 23% was average potential area, 30% was low potential area, and 20% was classified as no potential area. Based on the screening and ranking results supported by mapping output, detailed assessments on the top two potential basins (i.e. Malay Basin and Central Luconia Province) were conducted qualitatively which comprised the estimation of theoretical storage capacity using methods proposed by CSLF and US-DOE-NETL. From the calculation, the estimated theoretical storage capacity for Malay Basin was approximately 114 Gt (CSLF) and 75 Gt (US-DOE-NETL) while for Central Luconia Province was approximately 84 Gt (CSLF) and 56 Gt (US-DOE-NETL). The potential injection sites for both basins were identified at the depth ranging from 1000 to 1500 m considering they are warm basins. This study can provide a basis for further work to reduce the uncertainty in these estimates and also provide support to policy makers on future planning of carbon storage projects in Malaysia

Numerical Modelling for Geoengineering in Tropical Region

‘Tropics’ include all areas on the earth where the Sun contacts a point directly overhead at least once during the solar year, and located surrounding the Equator. The tropics comprise 40% of the earth’s surface area and contain 36% of earth’s landmass. Tropical is sometimes used in a general sense for a tropical climate which means warm to hot and moist year-round. Tropical areas tend to experience more rapid weathering because large amounts of consistent rainfall and constantly warm temperatures that influence the rate of weathering. Tropical areas usually experience both, dry and wet season. The wet /rainy /green season is the time of year, ranging from one or more months, when most of the average annual rainfall in a region falls. This rapid change of hot and cold weather more or less influenced the geology characteristics of the area such as the weathering rate, the soil formation. The uniqueness of geological characteristics in tropical regions has intrigued researchers to explore in details as to how this climate condition influenced the in situ geotechnical process and geological characteristics in order to identify the issues and challenges faced by geotechnical engineers when doing construction in the region. In an ever more globalized world, we are compelled to embrace the technological advancement in order to stay competitive. Hence, by using numerical methods to solve geotechnical problems and analysis are seen to be one of the initiatives to excel in this field especially in tropical geoengineering.Numerical analysis using finite element and finite difference methods has become a mainstream design tool within geotechnical engineering in the last decades. Numerical modelling is a mature yet vibrant research area in geotechnical engineering. Its advancement has been accelerated in recent years by many emerging computational techniques as well as the increasing availability of computational power. A wide spectrum of approaches, on the basis of continuously advancing understanding of soil behaviour, has been developed and applied to solve various problems in geotechnical engineering. The aim of this edited book is to present original research output by fellows and members of Centre of Tropical Geoengineering (GEOTROPIK) that applied numerical modelling in their analysis of geoengineering in tropical regions. The study area are mostly located in Asian region such as Malaysia, Thailand and Sri Lanka. This book is themed around numerical modeling application in rock mechanics and geology engineering, geotechnical engineering, and geoinformation to measure, manage and analyze the geospatial data relating the earth and its application in tropical regions. This theme is in line with the function of GEOTROPIK as research centre and provider of consultancy services. I thankfully acknowledge the authors for their valuable contribution in this book. Last but not least I feel indebted to reviewers, fellow editors and all those who helped directly or indirectly to make this book a successful and notable remembrance

Influence of initial conditions on unsaturated groundwater flow models

Slope failure in unsaturated soils is common in tropical countries due to the seasonal pattern of abundant rainfall preceding a period of prolonged drying. Much research has been undertaken to understand the behaviour of unsaturated slopes and reduce the number of catastrophic failures. The initial conditions are important factors in numerical modelling of the groundwater flow yet rarely considered in detail in the literature. This paper presents a parametric study of the initial conditions at a slope in Bukit Timah, Singapore. The intensity and duration of rainfall are varied to assess the effect on the pore-water pressure in the slope. The generated pore-water pressure profile is compared with field measurements and previous numerical studies. It is discovered that a low rainfall, with an intensity of 1x10-7 m/s over a period of 62 days, results in initial pore-water pressure which is consistent with data recorded at the field. Unlike the duration, changes in the rainfall intensity are shown to have a significant effect on the pore-water pressure in the slope. This study, therefore, demonstrates the importance of determining appropriate initial conditions in unsaturated groundwater flow analysis

Lightweight Expanded Clay Aggregate (LECA) as replacement materials for geotechnical application

Settlement is a common geotechnical problem occurs in soft soils. The replacement method is the easiest way to improve this problematic soil. This technique is carried out by removing the unwanted part of the soil and replacing it with a more suitable material or soil. This study focuses on using Lightweight Expanded Clay Aggregate (LECA) as a construction material to replace normal sand and aggregate in filling work. LECA is one of the best alternatives that can be used to improve soil properties because it is lightweight, strong and environmentally friendly. However, there are no specific guidelines for the LECA replacement in filling work. Therefore, this study was conducted to develop the construction procedures and LECA replacement requirements for geotechnical application in Malaysia. LECA aggregates have been used as a filling material to solve the settlement problem at Masjid At-Taqwa, Teluk Intan, Perak, Malaysia. LECA samples were collected from different location at different compaction levels for inspection of physical properties and quality of compaction examination. The level of compaction effort performed on LECA replacement represents by the number of passes. The relationship in compaction conditions related to LECA replacement is determined by two graphs namely LECA Compaction Effort and Targeted Compaction Level. The compaction quality of LECA aggregate filling work can be checked using Lightweight Deflectometer (LWD). The maximum desired density can be determined in advance. With reference to the LECA Compaction Effort plot established in this study, the number of passes that need to be performed during the placement work can be planned according to the desired compact density. Whereas, the compaction level, R% can be predicted based on the Target Compaction Level plot. An LWD test should then be carried out to ensure that the compacted density reaches the required level

Slope stability of landfill with waste degradation

Nowadays, a large amount of municipal solid waste (MSW) is generated due to the rapid urbanisation in developing countries leads to the demand for larger and higher capacity landfills. Bioreactor landfill technology has been introduced to accelerate the stability of landfill and to solve the issue of limited landfill area. However, the accelerated degradation of the refuse in bioreactor landfills also considerably changes the geotechnical characteristics of the waste in the landfill and thereby increases the concern for waste stability. Hence, this study aims to analyse the stability of both conventional and bioreactor landfill slope with the effects of waste degradation. Finite element method has been used in the slope stability analysis and the stability is presented by the factor of safety. The objectives of this study are i) to determine and assess the main parameter which influences the stability of the waste slope, ii) to determine the effects of waste degradation to the waste properties and iii) to obtain the factor of safety of the landfill slope using numerical analysis by finite element method. From the literature review, it is found that slope stability of a landfill mainly depends on the geotechnical properties of waste, such as moisture content, unit weight, shear strength parameters and hydraulic conductivity of waste. After the degradation process, engineering properties of field refuse are affected which includes the increased pore-water pressure and unit weight, decreased strength and lower hydraulic conductivity. Based on the analysis of conventional landfill slope stability by using Plaxis software, slope ratio of 1:3, 1:4 and 1:5 calculated safe with 1.69, 2.3 and 2.8 whereas the analysis of bioreactor landfill slope stability calculated safe only for slope ratio of 1:4 and 1:5 with 1.60 and 1.97. Moreover, the factor of safety for steeper slopes is lower and vice versa. From the parametric analysis, it is found that the full height of slope and unit weight of waste input affect the result analysis. This study is significant to evaluate the landfill slope stability with the effects of waste degradation and to ensure both conventional and bioreactor landfill slope stability for long periods. © BEIESP

The stability of diaphragm wall for deep excavation

Rapid urbanisation and the increase in population has led to massive use of underground spaces, especially in the city. Before an underground structure is built, the use of retaining structure is crucial in order to prevent the excavation from failure. Diaphragm wall is a widely used retaining structure, particularly for deep excavation. A holistic understanding of the performance and its behaviour is essential to provide stability of the soil retained. A parametric study by using Plaxis2D has been conducted to determine the factors affecting the stability of diaphragm wall and the excavation sites in underground Mass Rapid Transit station of Hospital Kuala Lumpur (HKLX). The objectives of this study are to determine the effect of diaphragm wall stiffness, groundwater drawdown and the depth of wall for deep excavation. The stability is captured based on the lateral deflection of wall, bending moment, safety factor and ground movement near the diaphragm wall. From the study, it is found that the diaphragm wall with high stiffness can reduce wall deflection up to 20% with the addition of 49% bending moment and achieve a high factor of safety. Furthermore, groundwater drawdown is seen reducing lateral deflection of the wall up to 1.08% as well as increasing the factor of safety. Finally, decreasing wall depth reduces the wall deflection by 0.38% and also the basal heaving

Back Analysis and Potential Remedial Approach for Failure Slope at Bukit Nanas, Kuala Lumpur

This study aims to validate the design parameters and stability of the slopes failure and propose acceptable remedial work by assessing the slope stability in Bukit Nanas, center of Kuala Lumpur. The slopes’ height is around 40 and 60 m with the gradient around 30°-45°. Totally 7 boreholes be carried out and the pertinent engineering properties were analyzed from laboratory testing and back analysis (in situ test). An established computer program SLOPE/W was used to carry out for slope stability analysis. The analysis method adopted was Morgenstern-Price’s Method. Based on the result of the field investigation and numerical analysis, the model of lowest factor of safety (FOS) that evaluated from the existing slope in critical section were selected and recommended for remedial work. Two option of remedial slope design had been proposed. The first option is soil nailing with grid beam and proposed drain while the second option is hybrid anchor with grid beam and proposed drain. Both options are used to improve the slope stability, but first option had been chosen as higher FOS and more efficient option. This remedial approach based on the main cause of slope failure in Malaysia can applied as reference in future slope remedial design

Keberkesanan kaedah pembelajaran berasaskan masalah dalam meningkatkan kemahiran berfikir aras tinggi dan menyelesaikan masalah dalam kalangan pelajar

Aspirasi negara yang diilhamkan dalam Wawasan 2020 ialah mencapai taraf negara maju. Hal ini telah meletakkan kepentingan yang sangat tinggi terhadap pendidikan sebagai pemacu untuk mencapai matlamat menjadi sebuah negara maju yang mampu mendepani cabaran dan permintaan ekonomi yang dipacu oleh sains dan teknologi, seperti yang telah digariskan dalam Pelan Pembangunan Pendidikan Malaysia. Pembelajaran Berasaskan Masalah (PBM) adalah satu pendekatan pengajaran berasaskan masalah sebenar, yang melibatkan penggunaan pelbagai kemahiran untuk menyelesaikannya. Kajian kuasi-eksperimental ini bertujuan mengkaji keberkesanan kaedah PBM dalam meningkatkan Kemahiran Berfikir Aras Tinggi (KBAT) dan kemahiran menyelesaikan masalah pelajar. Kajian ini mengambil masa selama lapan minggu. Instrumen yang digunakan dalam kajian ini ialah soalan ujian pra-pasca, senarai semak dan soal selidik. Kajian ini melibatkan 71 orang responden dari Sekolah Menengah Kebangsaan Tun Ismail yang terbahagi kepada dua kumpulan, iaitu kumpulan rawatan dan kumpulan kawalan. Kesemua responden ini ialah kumpulan pelajar yang mengambil mata pelajaran sains tingkatan empat. Data yang diperoleh dianalisis secara deskriptif dan inferensi menggunakan perisian Statistical packages for Social Science Version 21.0 (SPSS). Hasil dapatan kajian ini membuktikan kaedah PBM berjaya meningkatkan Kemahiran Berfikir Aras Tinggi (KBAT) dan kemahiran menyelesaikan masalah pelajar. Pelajar juga menunjukkan persepsi positif terhadap kaedah PBM ini. Dapatan kajian ini menggambarkan teknik pengajaran dan pembelajaran yang berbeza, menarik serta berkesan dari kaedah tradisional mampu meningkatkan kemahiran pelajar

Effectiveness of coffee husk ash and coconut fiber in improving peat properties

Peat is a well-known problematic soil associated with poor engineering properties because its engineering with low shear strength, highly compressible, high moisture content. The characteristics make it unsuitable for construction in its natural stage. Thus, this study determines the soil properties of untreated peat soil and assesses the changes in strength of the treated peat soil using the admixture of Coffee Husk Ash (CHA) and Coconut Fibre (CF). The percentage of CF used is 0.50%, 0.75% and 1.0% meanwhile the percentage of CHA used was 5%, 6%, and 7% by the weight of the soil sample. The peat soil for this study were retrieved from Mardi Pontian in Johor. Soil properties such as moisture content, bulk density, and the Atterberg limit have been tested. The result of the Standard Proctor test in this study determined the Optimum Moisture Content and Maximum Dry Density of soil samples. The strength of these samples has been determined by using the Unconfined Compressive Strength (UCS). The physical properties for untreated peat soil with the moisture content of 250%, organic content about 77%, the specific gravity was in the range of 1.48–1.8. The Atterberg limit for liquid limit is 230. The compaction test results has shown decrement in maximum dry density (MDD) but an increase in strength with the addition of CHA and CF in peat soil. According to the findings, 0.5% of Coconut Fiber improves the engineering properties of peat soil (CF)

Assessment of physicochemical parameters for the drinking water quality in the vicinity of Nawabshah City, Sindh, Pakistan

Quality of water may differ according to the geography of the region, due to that the quality of water is big concern worldwide, because majority of disease caused by the poor quality of drinking water. Subsequently realizing the significance of drinking water quality with in the central part of the Sindh province, this research work was carried out to assess the drinking water quality within the Nawabshah city, where the single source of supply water is the Gajrawah after the conventional treatment through the open ponds. In this study seven physicochemical parameter were investigated and laboratorial investigations demonstrated that the pH values were found with the WHO limits, TDS & EC values were found within the acceptable limits, except in one residential area, Turbidity was also high at all the locations only one area (Marium road colony) was found within the standards, furthermore, the hardness was present in all the samples at all the locations, which indicate that the water supplied to public was hard in nature. In addition to that Temperature and Dissolved Oxygen were found safe and within the limits and it was concluded that the water supplied to residents of the inspected areas were found not fit for drinking and it is suggested that the water supply, should be improved and essential steps should be taken to treat the water