Depleted Uranium (DU) ammunitions were used by the U.S.A and UK troops in an open environment for... more Depleted Uranium (DU) ammunitions were used by the U.S.A and UK troops in an open environment for the first time in history against Iraq on civilians and military targets during Gulf wars in 1991-2003. Spatial distribution and risk assessment of soil in the estimated sites at Basrah Governorate with uranium contaminations have been screened using statistics and geographic information system (GIS) methods, and a performance model of predication distribution and potential distant values of DU and other polluted components were detected by data collection. An interpolation technique was practiced in order to accomplish certainties in the data set and to decrease the influence of outliers. After choosing a tailored model, parameters can be recycled with the data to estimate Uranium concentrations at unsampled locations using the kriging technique to define the weights of adjacent monitoring in the predicating underground surfaces similar to contaminated elements and radionuclides of ura...
Conventionally, passive piles are used in resisting lateral movement of soil mass in landslide pr... more Conventionally, passive piles are used in resisting lateral movement of soil mass in landslide prevention measure. Such piles are installed vertically in a row, so that pile resistance is generated through the shearing between the embedded pile lengths with slope surface. While cast in-situ concrete piles with diameter up to 1 m are still widely used in practice, a new type of pile called the small diameter steel piles (SDSP) has been developed recently as alternative. With diameter spanning only between 90 mm to 300 mm, SDSP is expected to function as both preventive piles as well as reinforcing rod in landslide prone slopes. This paper intends to shade light on the prevention mechanism of small diameter steel piles (SDSP) and how multirow arrangement of piles affects the reinforced slope failure in landslide prevention. To that end, laboratory scale experiment using direct shear test was performed to replicate the lateral soil movement induced by landslide in which, Toyoura sand a...
Karst region representing 7-12% of the earth’s continental areas and 25% of world population is e... more Karst region representing 7-12% of the earth’s continental areas and 25% of world population is either completely or partially dependent on water from karst aquifer for drinking. Fresh water supply is expected to be a major problem in this century due to high demand from industrial needs and domestics usage. Contamination is a natural risk to the groundwater in the karst aquifer due to the characteristics of karstified host rock itself. The main process contributes to karst unique is the dissolution of bedrock by slightly acidic water. This review is aiming to provide a better understanding of the early evolution of karst aquifer numerical models. This paper also discussed the influence of several parameters on the genesis of karst evolution. We investigate on different conceptual models of karst aquifer and how they translated into numerical models from basic 1-Dimension model to complex 3-Dimension models. We also study the differing complexity and hence differing data requirements to model the complex ...
Depleted uraniu m (DU) is known to affect the health and well-being of humans. Exposure to DU wea... more Depleted uraniu m (DU) is known to affect the health and well-being of humans. Exposure to DU weapons used by the United States troops and its allies has caused several types of exotic d iseases, congenital malformat ions, and malignant tumors that have resulted in mild to severe abnormalit ies. This study aims to determine the amount of DU concentrations present in humans exposed to DU weapons. The Basrah District was chosen as the study site because this district was involved in the Gulf War in 1991 to 2003. Data were collected fro m hospitals, universities, and health institutes from 1989 to 2010. Blood, tissues, bones, urine, and teeth in fected by cancer where comp iledas data samples. The DU ratios of each person in the diverse sites of the Basrah Governorate were obtained for analysis. Descriptive statistics was obtained for the dataset. Results of this study shows that the mean of the DU ratio in the infected samples was 0.018 ppm in 1994 and was 1.27 pp m in 2010. Results also indicating that the DU rat io exceeded the standards level significantly. The DU concentration rates increase with increasing the years, due to the accumulation of U 238 series radioisotopes in the human organs. The lung has the highest DU ratio, fo llo wed by the kidney, bones, urinary bladder, and teeth, successively. Analysis findings indicate the presence of radiological pollution significantly in some areas, and lead to uranium enters the human body through respiration or through ingestion of contaminated food and drink. A irborne uraniu m also contains particles that accumulate in the human organs.
applicable for producing good ERV which varied due to the moisture content and density variations... more applicable for producing good ERV which varied due to the moisture content and density variations. Furthermore, this study also found that the ERV was highly influence by air void content which caused by loose soil embankment condition used in this study. Hence, it was found that ERV produced was relative to the types of array used during the field measurement in line with the variation of physical soil characteristics.
ABSTRACT Geophysical methods originally championed by geophysicists are becoming popular in the c... more ABSTRACT Geophysical methods originally championed by geophysicists are becoming popular in the civil engineering field. In the past, most engineers applied their conventional method with rare to any other alternative method. This study describes some of the civil engineering applications discourse where the geophysical method is especially suitable in the preliminary stage of site assessment. Some of the geophysical method which can assist the civil engineering works is still rarely understood for several reasons. Hence, this study presents a resistivity and seismic refraction method applied in several civil engineering problems in Malaysia such as in geotechnical engineering, rock mechanics and engineering geology, water and environmental engineering and pavement engineering. The utilization of geophysical method can increase the effectiveness of civil engineering works since it can provide the information which the conventional civil engineering method was hard to determine due to the concern of money, time and quality. For example, the method helps to reduce the number of conventional drilling method and possibly decides a critical spot of interest which directly decreases the cost of the project. Some of the common earth materials and related parameter in civil engineering application that can be utilized by the geophysical method are minerals, soils, rocks, water, subsurface layers, thickness and depth. The results produced by the geophysical survey increase the awareness of civil engineers of their wide area of applications. The utilization of this method have been successfully used in the civil engineering field and has the potential to be integrated with a conventional method to produce reliable information thus enhance the project effectiveness especially during the design and construction stages.
... For all sample sizes the Gringorten method produces the best estimate. This is followed by th... more ... For all sample sizes the Gringorten method produces the best estimate. This is followed by the Cunnane and Blom method. 6. References Ahmad Shukri Yahaya, Nor Azam Ramli, Aeizaal Azman Abdul Wahab (2007). Finding ...
Journal of Geotechnical and Geoenvironmental Engineering, 2013
ABSTRACT The merits of incorporating the spatial variability of soil properties into slope reliab... more ABSTRACT The merits of incorporating the spatial variability of soil properties into slope reliability analyses have been demonstrated by many researchers. However, the suitability of the use of limit equilibrium methods (LEMs) for calculating the minimum factor of safety (FS) of a spatially variable slope modeled by a random field is not well understood. The present paper investigates this topic by performing a series of analyses using circular and noncircular LEMs and a strength reduction method based on finite-element analysis (FE SRM). The LEMs are found to encounter three possible issues in random fields, including (1) noncircular slip surfaces, (2) a significant increase in the complexity of an optimization problem, and (3) failure to converge. The LEM analysis results in random fields can only be reliable when these three issues are adequately addressed. It is found that a noncircular rigorous LEM with a carefully selected interslice force function may work adequately in random fields. Moreover, the FE SRM is suitable for random field cases because of its robustness, accuracy, and versatility.
Triaxial compression tests were conducted to evaluate the response of randomly distributed fibre ... more Triaxial compression tests were conducted to evaluate the response of randomly distributed fibre on the strength of reinforced silty sand. In this study, oil palm empty fruit bunch (OPEFB) fibre was mixed with silty sand soil to investigate the increase of shear strength during triaxial compression. The specimens were tested under drained and undrained conditions with 0.25% and 0.5% content of OPEFB fibres of different lengths (i.e. 15 mm, 30 mm and 45 mm). In addition, OPEFB fibres coated with acrylic butadiene styrene thermoplastic were tested to determine the effect of coating on reinforcement. Inclusion of randomly distributed discrete fibres significantly improved the shear strength of silty sand. Coated OPEFB fibres increased the shear strength of silty sand much more compared to uncoated fibres. Coating fibres increases interface friction between fibre and soil particles by increasing the surface area. Reinforced silty sand containing 0.5% coated fibres of 30 mm length exhibited approximately 25% increase in friction angle and 35% in cohesion under undrained loading conditions compared to those of unreinforced silty sand. The results indicate that the shear strength parameters of the soil-fibre mixture (i.e. F 0 and c 0 ) can be improved significantly.
The 2004 Banda Aceh earthquake and ensuing Andaman mega tsunami that killed a quarter million peo... more The 2004 Banda Aceh earthquake and ensuing Andaman mega tsunami that killed a quarter million people worldwide is a wake-up call to many. Active research was initiated in Universiti Sains Malaysia (USM) immediately after the infamous event with the ...
Abstract- Gypseous soil is one of problematic soils to be used as foundation of road, building an... more Abstract- Gypseous soil is one of problematic soils to be used as foundation of road, building and other structures. It is considerably strong and has good properties when it is dry. The problem appears when constructing heavy buildings or hydraulic structures on these soils after wetted by water from rainfall or from the raising of water table level from any source and leaching the salts from the soil. The primary objective of this paper is to presents the current state of the gypseous soil subject to leaching. A review is provided aiming to discuss the effect of gypsum content and leaching on gypseous soil. T Index Terms- Gypseous soil, Gypsum content, Leaching
Program Pengajian Siswazah menjadi lebih relevan dalam landskap pendidikan negara apabila negara ... more Program Pengajian Siswazah menjadi lebih relevan dalam landskap pendidikan negara apabila negara mensasarkan seramai 60,000 pemegang PhD di Malaysia pada tahun 2023. Program ini bukan sahaja menggarap usaha untuk menyediakan graduan berkelayakan tinggi yang dapat menyumbang kepada tenaga kerja minda kelas pertama, tetapi juga sebagai kaedah mencapai matlamat pekerja berpendapatan tinggi di negara ini. Sebagaimana program pengajian siswazah lain di dunia, pengajian siswazah di Malaysia juga tidak terkecuali daripada menghadapi pelbagai isu dan cabaran. Kajian Majlis Dekan Pengajian Siswazah Malaysia (MDPS) ini bertujuan membentuk Pelan Halatuju Pengajian Siswazah Malaysia bagi 2017-2025. Pelan halatuju ini dibentuk hasil daripada kajian terhadap amalan pengurusan, proses penyampaian pembelajaran dan pengajaran, dan isu serta cabaran yang dihadapinya. Sebanyak 22 buah universiti tempatan telah mengambil bahagian dalam kajian ini. Soal selidik ke atas pelajar, pensyarah dan pentadbir e...
The reduction of shear strength parameters of the soil in the slopes as well as the reduction of ... more The reduction of shear strength parameters of the soil in the slopes as well as the reduction of suction as the soil become saturated during prolonged rainy seasons are the two main causes of slope failures in Malaysian residual soils. In this study, a total of 227 shear strength parameters were obtained from 29 slope failures in Penang Island and Baling. Both locations are located in Northern Malaysia. In addition, 35 shear strength parameters were also obtained from 10 stable slopes, also at the same locations. Disturbed soil samples were taken at a depth of 100mm from the existing ground surface. Field bulk density tests were carried out at all the location where soil samples were taken. The field bulk density results were later used to re-compact the soil for the consolidated drained shear box tests to be carried out in laboratory. The objective of the research is to determine the threshold values of the effective shear strength parameters of soil taken from both the slope failu...
Non-destructive test which refers to electrical resistivity method is recently popular in enginee... more Non-destructive test which refers to electrical resistivity method is recently popular in engineering, environmental, archaeological and mining studies. Based on the previous studies, the results on electrical resistivity interpretation were often debated due to lack of clarification and evidences in quantitative perspective. Traditionally, most of the previous result interpretations were depending on qualitative point of view which is risky to produce unreliable outcomes. In order to minimise those problems, this study has performed a laboratory experiment on soil box electrical resistivity test which was supported by an additional basic physical properties of soil test like particle size distribution test (d), moisture content test (w), density test (ρ bulk ) and Atterberg limit test (LL, PL and PI). The test was performed to establish a series of electrical resistivity value (ERV) with different quantity of water content for clayey silt and silty sand in loose and dense condition. Apparently, the soil resistivity value was different under loose (L) and dense (C) conditions with moisture content and density variations (silty SAND = ERV Loose : 600 -7300 Ωm & ERV Dense : 490 -7900 Ωm while Clayey SILT = ERV Loose : 13 -7700 Ωm & ERV Dense : 14 -8400 Ωm) due to several factors. Moreover, correlation of moisture content (w) and density (ρ bulk ) due to the ERV was established as follows; Silty SAND: w (L) = 638.8ρ -0.418 , w (D) = 1397.1ρ -0.574 , ρ Bulk(L) = 2.6188e -6E-05ρ , ρ Bulk(D) = 4.099ρ -0.07 while Clayey SILT: w (L) = 109.98ρ -0.268 , w (D) = 121.88ρ -0.363 , ρ Bulk(L ) = -0.111ln(ρ) + 1.7605, ρ Bulk(D) = 2.5991ρ -0.037 with determination coefficients, R 2 that varied from 0.5643 -0.8927. This study was successfully demonstrated that the consistency of ERV was greatly influenced by the variation of soil basic physical properties (d, w, ρ Bulk , LL, PL and PI). Finally, the reliability of the ERV result interpretation can be enhanced due to its ability to produce a meaningful outcome based on supported data from basic geotechnical properties. Ujian tak musnah yang merujuk kepada kaedah kerintangan elektrik semakin banyak digunakan dalam kajian kejuruteraan, alam sekitar, arkeologi dan perlombongan. Berdasarkan kajian terdahulu, interpretasi keputusan kerintangan elektrik sering diperdebatkan disebabkan kekurangan bukti kajian dalam perspektif kuantitatif. Kebiasaannya interpretasi keputusan kerintangan elektrik banyak bergantung kepada perspektif kualitatif justeru berkemungkinan besar berisiko tinggi untuk menghasilkan keputusan yang salah. Maka, kajian ini telah menjalankan uji kaji makmal kerintangan elektrik tanah disokong oleh uji kaji sifat asas fizikal tanah seperti uji kaji taburan saiz zarah (d), kandungan lembapan (w), ketumpatan (ρ bulk ) dan had Atterberg (LL, PL dan PI). Uji kaji dijalankan untuk menghasilkan satu siri nilai kerintangan elektrik (ERV) berdasarkan kuantiti air yang berbeza terhadap lempung berkelodak dan kelodak berpasir dalam keadaan longgar dan juga mampat. Hasil keputusan menunjukkan nilai kerintangan tanah adalah berbeza dalam keadaan longgar (L) dan mampat (C) serta variasi kandungan air dan juga ketumpatan (pasir berkelodak =
Slope failures always occur in Malaysia especially during the rainy seasons. They cause damage to... more Slope failures always occur in Malaysia especially during the rainy seasons. They cause damage to properties and fatalities. In this study, a total of 24 one dimensional consolidation tests were carried out on soil samples taken from 16 slope failures in Penang Island and in Baling, Kedah. The slope failures in Penang Island are within the granitic residual soil while in Baling, Kedah they are situated within the sedimentary residual soil. Most of the disturbed soil samples were taken at 100mm depth from the existing soil surface while some soil samples were also taken at 400, 700 and 1000mm depths from the existing soil surface. They were immediately placed in 2 layers of plastic bag to prevent moisture loss. Field bulk density tests were also carried out at all the locations where soil samples were taken. The field bulk density results were later used to re-compact the soil samples for the consolidation tests. The objective of the research is to determine the slow shearing rate to be used in consolidated drained shear box for residual soils taken from slope failures so that the effective shear strength parameters can be determined. One dimensional consolidation tests were used to determine the slow shearing rate. The slow shearing rate found in this study to be used in the consolidated drained shear box tests especially for Northern Malaysian residual soils was 0.286mm/minute.
Geopolymer technology have been developed and explored especially in the construction material fi... more Geopolymer technology have been developed and explored especially in the construction material field. However, lack of research related to geopolymer stabilized soil. In this research, the utilization of geopolymer has been investigated to stabilize the soil including the factors that affecting the geopolymerization process. Unconfined compressive test (UCT) used as indicator to the strength development and hence evaluating the performance of geopolymer stabilized soil. This paper focusing on the effect of fly ash/alkaline activator ratio, Na 2 SiO 3 /NaOH ratio and curing time on geopolymer stabilized soil. A various mix design at different fly ash/alkaline activator ratio, Na 2 SiO 3 /NaOH ratio were prepared and cured for 7 and 28 days. Molarity and the percentage of geopolymer to soil were fixed at 10 molar and 8 percent respectively. Then, the UCT tests were carried out on 38mm diameter x 76mm height specimens. The highest strength obtained at the fly ash/alkaline activator ratio 2.5 and Na 2 SiO 3 /NaOH ratio 2.0 at 28 days curing time.
IOP Conference Series: Materials Science and Engineering, 2016
Recycled tyres have been used in many geotechnical engineering projects such as soil improvement,... more Recycled tyres have been used in many geotechnical engineering projects such as soil improvement, soil erosion and slope stability. Recycled tyres mainly in chip and shredded form are highly compressible under low and normal pressures. This characteristic would cause challenging problems in some applications of soil stabilization such as retaining wall and river bank projects. For high tensile stress and low tensile strain the use of fiberglass would be a good alternative for recycled tyre in some cases. To evaluate fiberglass as an alternative for recycled tyre, this paper focused on tests of tensile tests which have been carried out between fiberglass and recycled tyre strips. Fibreglass samples were produced from chopped strand fibre mat, a very low-cost type of fibreglass, which is cured by resin and hardener. Fibreglass samples in the thickness of 1 mm, 2 mm, 3 mm and 4 mm were developed 100 mm x 300 mm pieces. It was found that 3 mm fibreglass exhibited the maximum tensile load (MTL) and maximum tensile stress (MTS) greater than other samples. Statistical analysis on 3 mm fibreglass indicated that in the approximately equal MTL fibreglass samples experienced 2% while tyre samples experienced 33.9% ultimate tensile strain (UTST) respectively. The results also showed an approximately linear relationship between stress and strain for fibreglass samples and Young's modulus (E), ranging from 3581 MPa to 4728 MPa.
Depleted Uranium (DU) ammunitions were used by the U.S.A and UK troops in an open environment for... more Depleted Uranium (DU) ammunitions were used by the U.S.A and UK troops in an open environment for the first time in history against Iraq on civilians and military targets during Gulf wars in 1991-2003. Spatial distribution and risk assessment of soil in the estimated sites at Basrah Governorate with uranium contaminations have been screened using statistics and geographic information system (GIS) methods, and a performance model of predication distribution and potential distant values of DU and other polluted components were detected by data collection. An interpolation technique was practiced in order to accomplish certainties in the data set and to decrease the influence of outliers. After choosing a tailored model, parameters can be recycled with the data to estimate Uranium concentrations at unsampled locations using the kriging technique to define the weights of adjacent monitoring in the predicating underground surfaces similar to contaminated elements and radionuclides of ura...
Conventionally, passive piles are used in resisting lateral movement of soil mass in landslide pr... more Conventionally, passive piles are used in resisting lateral movement of soil mass in landslide prevention measure. Such piles are installed vertically in a row, so that pile resistance is generated through the shearing between the embedded pile lengths with slope surface. While cast in-situ concrete piles with diameter up to 1 m are still widely used in practice, a new type of pile called the small diameter steel piles (SDSP) has been developed recently as alternative. With diameter spanning only between 90 mm to 300 mm, SDSP is expected to function as both preventive piles as well as reinforcing rod in landslide prone slopes. This paper intends to shade light on the prevention mechanism of small diameter steel piles (SDSP) and how multirow arrangement of piles affects the reinforced slope failure in landslide prevention. To that end, laboratory scale experiment using direct shear test was performed to replicate the lateral soil movement induced by landslide in which, Toyoura sand a...
Karst region representing 7-12% of the earth’s continental areas and 25% of world population is e... more Karst region representing 7-12% of the earth’s continental areas and 25% of world population is either completely or partially dependent on water from karst aquifer for drinking. Fresh water supply is expected to be a major problem in this century due to high demand from industrial needs and domestics usage. Contamination is a natural risk to the groundwater in the karst aquifer due to the characteristics of karstified host rock itself. The main process contributes to karst unique is the dissolution of bedrock by slightly acidic water. This review is aiming to provide a better understanding of the early evolution of karst aquifer numerical models. This paper also discussed the influence of several parameters on the genesis of karst evolution. We investigate on different conceptual models of karst aquifer and how they translated into numerical models from basic 1-Dimension model to complex 3-Dimension models. We also study the differing complexity and hence differing data requirements to model the complex ...
Depleted uraniu m (DU) is known to affect the health and well-being of humans. Exposure to DU wea... more Depleted uraniu m (DU) is known to affect the health and well-being of humans. Exposure to DU weapons used by the United States troops and its allies has caused several types of exotic d iseases, congenital malformat ions, and malignant tumors that have resulted in mild to severe abnormalit ies. This study aims to determine the amount of DU concentrations present in humans exposed to DU weapons. The Basrah District was chosen as the study site because this district was involved in the Gulf War in 1991 to 2003. Data were collected fro m hospitals, universities, and health institutes from 1989 to 2010. Blood, tissues, bones, urine, and teeth in fected by cancer where comp iledas data samples. The DU ratios of each person in the diverse sites of the Basrah Governorate were obtained for analysis. Descriptive statistics was obtained for the dataset. Results of this study shows that the mean of the DU ratio in the infected samples was 0.018 ppm in 1994 and was 1.27 pp m in 2010. Results also indicating that the DU rat io exceeded the standards level significantly. The DU concentration rates increase with increasing the years, due to the accumulation of U 238 series radioisotopes in the human organs. The lung has the highest DU ratio, fo llo wed by the kidney, bones, urinary bladder, and teeth, successively. Analysis findings indicate the presence of radiological pollution significantly in some areas, and lead to uranium enters the human body through respiration or through ingestion of contaminated food and drink. A irborne uraniu m also contains particles that accumulate in the human organs.
applicable for producing good ERV which varied due to the moisture content and density variations... more applicable for producing good ERV which varied due to the moisture content and density variations. Furthermore, this study also found that the ERV was highly influence by air void content which caused by loose soil embankment condition used in this study. Hence, it was found that ERV produced was relative to the types of array used during the field measurement in line with the variation of physical soil characteristics.
ABSTRACT Geophysical methods originally championed by geophysicists are becoming popular in the c... more ABSTRACT Geophysical methods originally championed by geophysicists are becoming popular in the civil engineering field. In the past, most engineers applied their conventional method with rare to any other alternative method. This study describes some of the civil engineering applications discourse where the geophysical method is especially suitable in the preliminary stage of site assessment. Some of the geophysical method which can assist the civil engineering works is still rarely understood for several reasons. Hence, this study presents a resistivity and seismic refraction method applied in several civil engineering problems in Malaysia such as in geotechnical engineering, rock mechanics and engineering geology, water and environmental engineering and pavement engineering. The utilization of geophysical method can increase the effectiveness of civil engineering works since it can provide the information which the conventional civil engineering method was hard to determine due to the concern of money, time and quality. For example, the method helps to reduce the number of conventional drilling method and possibly decides a critical spot of interest which directly decreases the cost of the project. Some of the common earth materials and related parameter in civil engineering application that can be utilized by the geophysical method are minerals, soils, rocks, water, subsurface layers, thickness and depth. The results produced by the geophysical survey increase the awareness of civil engineers of their wide area of applications. The utilization of this method have been successfully used in the civil engineering field and has the potential to be integrated with a conventional method to produce reliable information thus enhance the project effectiveness especially during the design and construction stages.
... For all sample sizes the Gringorten method produces the best estimate. This is followed by th... more ... For all sample sizes the Gringorten method produces the best estimate. This is followed by the Cunnane and Blom method. 6. References Ahmad Shukri Yahaya, Nor Azam Ramli, Aeizaal Azman Abdul Wahab (2007). Finding ...
Journal of Geotechnical and Geoenvironmental Engineering, 2013
ABSTRACT The merits of incorporating the spatial variability of soil properties into slope reliab... more ABSTRACT The merits of incorporating the spatial variability of soil properties into slope reliability analyses have been demonstrated by many researchers. However, the suitability of the use of limit equilibrium methods (LEMs) for calculating the minimum factor of safety (FS) of a spatially variable slope modeled by a random field is not well understood. The present paper investigates this topic by performing a series of analyses using circular and noncircular LEMs and a strength reduction method based on finite-element analysis (FE SRM). The LEMs are found to encounter three possible issues in random fields, including (1) noncircular slip surfaces, (2) a significant increase in the complexity of an optimization problem, and (3) failure to converge. The LEM analysis results in random fields can only be reliable when these three issues are adequately addressed. It is found that a noncircular rigorous LEM with a carefully selected interslice force function may work adequately in random fields. Moreover, the FE SRM is suitable for random field cases because of its robustness, accuracy, and versatility.
Triaxial compression tests were conducted to evaluate the response of randomly distributed fibre ... more Triaxial compression tests were conducted to evaluate the response of randomly distributed fibre on the strength of reinforced silty sand. In this study, oil palm empty fruit bunch (OPEFB) fibre was mixed with silty sand soil to investigate the increase of shear strength during triaxial compression. The specimens were tested under drained and undrained conditions with 0.25% and 0.5% content of OPEFB fibres of different lengths (i.e. 15 mm, 30 mm and 45 mm). In addition, OPEFB fibres coated with acrylic butadiene styrene thermoplastic were tested to determine the effect of coating on reinforcement. Inclusion of randomly distributed discrete fibres significantly improved the shear strength of silty sand. Coated OPEFB fibres increased the shear strength of silty sand much more compared to uncoated fibres. Coating fibres increases interface friction between fibre and soil particles by increasing the surface area. Reinforced silty sand containing 0.5% coated fibres of 30 mm length exhibited approximately 25% increase in friction angle and 35% in cohesion under undrained loading conditions compared to those of unreinforced silty sand. The results indicate that the shear strength parameters of the soil-fibre mixture (i.e. F 0 and c 0 ) can be improved significantly.
The 2004 Banda Aceh earthquake and ensuing Andaman mega tsunami that killed a quarter million peo... more The 2004 Banda Aceh earthquake and ensuing Andaman mega tsunami that killed a quarter million people worldwide is a wake-up call to many. Active research was initiated in Universiti Sains Malaysia (USM) immediately after the infamous event with the ...
Abstract- Gypseous soil is one of problematic soils to be used as foundation of road, building an... more Abstract- Gypseous soil is one of problematic soils to be used as foundation of road, building and other structures. It is considerably strong and has good properties when it is dry. The problem appears when constructing heavy buildings or hydraulic structures on these soils after wetted by water from rainfall or from the raising of water table level from any source and leaching the salts from the soil. The primary objective of this paper is to presents the current state of the gypseous soil subject to leaching. A review is provided aiming to discuss the effect of gypsum content and leaching on gypseous soil. T Index Terms- Gypseous soil, Gypsum content, Leaching
Program Pengajian Siswazah menjadi lebih relevan dalam landskap pendidikan negara apabila negara ... more Program Pengajian Siswazah menjadi lebih relevan dalam landskap pendidikan negara apabila negara mensasarkan seramai 60,000 pemegang PhD di Malaysia pada tahun 2023. Program ini bukan sahaja menggarap usaha untuk menyediakan graduan berkelayakan tinggi yang dapat menyumbang kepada tenaga kerja minda kelas pertama, tetapi juga sebagai kaedah mencapai matlamat pekerja berpendapatan tinggi di negara ini. Sebagaimana program pengajian siswazah lain di dunia, pengajian siswazah di Malaysia juga tidak terkecuali daripada menghadapi pelbagai isu dan cabaran. Kajian Majlis Dekan Pengajian Siswazah Malaysia (MDPS) ini bertujuan membentuk Pelan Halatuju Pengajian Siswazah Malaysia bagi 2017-2025. Pelan halatuju ini dibentuk hasil daripada kajian terhadap amalan pengurusan, proses penyampaian pembelajaran dan pengajaran, dan isu serta cabaran yang dihadapinya. Sebanyak 22 buah universiti tempatan telah mengambil bahagian dalam kajian ini. Soal selidik ke atas pelajar, pensyarah dan pentadbir e...
The reduction of shear strength parameters of the soil in the slopes as well as the reduction of ... more The reduction of shear strength parameters of the soil in the slopes as well as the reduction of suction as the soil become saturated during prolonged rainy seasons are the two main causes of slope failures in Malaysian residual soils. In this study, a total of 227 shear strength parameters were obtained from 29 slope failures in Penang Island and Baling. Both locations are located in Northern Malaysia. In addition, 35 shear strength parameters were also obtained from 10 stable slopes, also at the same locations. Disturbed soil samples were taken at a depth of 100mm from the existing ground surface. Field bulk density tests were carried out at all the location where soil samples were taken. The field bulk density results were later used to re-compact the soil for the consolidated drained shear box tests to be carried out in laboratory. The objective of the research is to determine the threshold values of the effective shear strength parameters of soil taken from both the slope failu...
Non-destructive test which refers to electrical resistivity method is recently popular in enginee... more Non-destructive test which refers to electrical resistivity method is recently popular in engineering, environmental, archaeological and mining studies. Based on the previous studies, the results on electrical resistivity interpretation were often debated due to lack of clarification and evidences in quantitative perspective. Traditionally, most of the previous result interpretations were depending on qualitative point of view which is risky to produce unreliable outcomes. In order to minimise those problems, this study has performed a laboratory experiment on soil box electrical resistivity test which was supported by an additional basic physical properties of soil test like particle size distribution test (d), moisture content test (w), density test (ρ bulk ) and Atterberg limit test (LL, PL and PI). The test was performed to establish a series of electrical resistivity value (ERV) with different quantity of water content for clayey silt and silty sand in loose and dense condition. Apparently, the soil resistivity value was different under loose (L) and dense (C) conditions with moisture content and density variations (silty SAND = ERV Loose : 600 -7300 Ωm & ERV Dense : 490 -7900 Ωm while Clayey SILT = ERV Loose : 13 -7700 Ωm & ERV Dense : 14 -8400 Ωm) due to several factors. Moreover, correlation of moisture content (w) and density (ρ bulk ) due to the ERV was established as follows; Silty SAND: w (L) = 638.8ρ -0.418 , w (D) = 1397.1ρ -0.574 , ρ Bulk(L) = 2.6188e -6E-05ρ , ρ Bulk(D) = 4.099ρ -0.07 while Clayey SILT: w (L) = 109.98ρ -0.268 , w (D) = 121.88ρ -0.363 , ρ Bulk(L ) = -0.111ln(ρ) + 1.7605, ρ Bulk(D) = 2.5991ρ -0.037 with determination coefficients, R 2 that varied from 0.5643 -0.8927. This study was successfully demonstrated that the consistency of ERV was greatly influenced by the variation of soil basic physical properties (d, w, ρ Bulk , LL, PL and PI). Finally, the reliability of the ERV result interpretation can be enhanced due to its ability to produce a meaningful outcome based on supported data from basic geotechnical properties. Ujian tak musnah yang merujuk kepada kaedah kerintangan elektrik semakin banyak digunakan dalam kajian kejuruteraan, alam sekitar, arkeologi dan perlombongan. Berdasarkan kajian terdahulu, interpretasi keputusan kerintangan elektrik sering diperdebatkan disebabkan kekurangan bukti kajian dalam perspektif kuantitatif. Kebiasaannya interpretasi keputusan kerintangan elektrik banyak bergantung kepada perspektif kualitatif justeru berkemungkinan besar berisiko tinggi untuk menghasilkan keputusan yang salah. Maka, kajian ini telah menjalankan uji kaji makmal kerintangan elektrik tanah disokong oleh uji kaji sifat asas fizikal tanah seperti uji kaji taburan saiz zarah (d), kandungan lembapan (w), ketumpatan (ρ bulk ) dan had Atterberg (LL, PL dan PI). Uji kaji dijalankan untuk menghasilkan satu siri nilai kerintangan elektrik (ERV) berdasarkan kuantiti air yang berbeza terhadap lempung berkelodak dan kelodak berpasir dalam keadaan longgar dan juga mampat. Hasil keputusan menunjukkan nilai kerintangan tanah adalah berbeza dalam keadaan longgar (L) dan mampat (C) serta variasi kandungan air dan juga ketumpatan (pasir berkelodak =
Slope failures always occur in Malaysia especially during the rainy seasons. They cause damage to... more Slope failures always occur in Malaysia especially during the rainy seasons. They cause damage to properties and fatalities. In this study, a total of 24 one dimensional consolidation tests were carried out on soil samples taken from 16 slope failures in Penang Island and in Baling, Kedah. The slope failures in Penang Island are within the granitic residual soil while in Baling, Kedah they are situated within the sedimentary residual soil. Most of the disturbed soil samples were taken at 100mm depth from the existing soil surface while some soil samples were also taken at 400, 700 and 1000mm depths from the existing soil surface. They were immediately placed in 2 layers of plastic bag to prevent moisture loss. Field bulk density tests were also carried out at all the locations where soil samples were taken. The field bulk density results were later used to re-compact the soil samples for the consolidation tests. The objective of the research is to determine the slow shearing rate to be used in consolidated drained shear box for residual soils taken from slope failures so that the effective shear strength parameters can be determined. One dimensional consolidation tests were used to determine the slow shearing rate. The slow shearing rate found in this study to be used in the consolidated drained shear box tests especially for Northern Malaysian residual soils was 0.286mm/minute.
Geopolymer technology have been developed and explored especially in the construction material fi... more Geopolymer technology have been developed and explored especially in the construction material field. However, lack of research related to geopolymer stabilized soil. In this research, the utilization of geopolymer has been investigated to stabilize the soil including the factors that affecting the geopolymerization process. Unconfined compressive test (UCT) used as indicator to the strength development and hence evaluating the performance of geopolymer stabilized soil. This paper focusing on the effect of fly ash/alkaline activator ratio, Na 2 SiO 3 /NaOH ratio and curing time on geopolymer stabilized soil. A various mix design at different fly ash/alkaline activator ratio, Na 2 SiO 3 /NaOH ratio were prepared and cured for 7 and 28 days. Molarity and the percentage of geopolymer to soil were fixed at 10 molar and 8 percent respectively. Then, the UCT tests were carried out on 38mm diameter x 76mm height specimens. The highest strength obtained at the fly ash/alkaline activator ratio 2.5 and Na 2 SiO 3 /NaOH ratio 2.0 at 28 days curing time.
IOP Conference Series: Materials Science and Engineering, 2016
Recycled tyres have been used in many geotechnical engineering projects such as soil improvement,... more Recycled tyres have been used in many geotechnical engineering projects such as soil improvement, soil erosion and slope stability. Recycled tyres mainly in chip and shredded form are highly compressible under low and normal pressures. This characteristic would cause challenging problems in some applications of soil stabilization such as retaining wall and river bank projects. For high tensile stress and low tensile strain the use of fiberglass would be a good alternative for recycled tyre in some cases. To evaluate fiberglass as an alternative for recycled tyre, this paper focused on tests of tensile tests which have been carried out between fiberglass and recycled tyre strips. Fibreglass samples were produced from chopped strand fibre mat, a very low-cost type of fibreglass, which is cured by resin and hardener. Fibreglass samples in the thickness of 1 mm, 2 mm, 3 mm and 4 mm were developed 100 mm x 300 mm pieces. It was found that 3 mm fibreglass exhibited the maximum tensile load (MTL) and maximum tensile stress (MTS) greater than other samples. Statistical analysis on 3 mm fibreglass indicated that in the approximately equal MTL fibreglass samples experienced 2% while tyre samples experienced 33.9% ultimate tensile strain (UTST) respectively. The results also showed an approximately linear relationship between stress and strain for fibreglass samples and Young's modulus (E), ranging from 3581 MPa to 4728 MPa.
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Papers by Fauziah Ahmad