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2024 | Book

Proceedings of AWAM International Conference on Civil Engineering 2022 - Volume 3

AICCE, Sustainability and Resiliency


About this book

This book gathers the latest research, innovations, and applications in the field of civil engineering, as presented by leading national and international academics, researchers, engineers, and postgraduate students at the AWAM International Conference on Civil Engineering 2022 (AICCE’22), held in Penang, Malaysia on February 15-17, 2022. The book covers highly diverse topics in the main fields of civil engineering, including structural and earthquake engineering, environmental engineering, geotechnical engineering, highway and transportation engineering, water resources engineering, and geomatic and construction management. In line with the conference theme, “Sustainability And Resiliency: Re-Engineering the Future”, which relates to the United Nations’ 17 Global Goals for Sustainable Development, it highlights important elements in the planning and development stages to establish design standards beneficial to the environment and its surroundings. The contributions introduce numerous exciting ideas that spur novel research directions and foster multidisciplinary collaborations between various specialists in the field of civil engineering.
This book is part of a 3-volume series of these conference proceedings, it represents Volume 3 in the series.

Table of Contents


Geotechnical Engineering

Effect of Soil Restraint to Long Slender Pile

Soil restraint has been identified as a possible mechanism that can pose a positive effect to long slender pile in different soil deposits, and this effect has not been explicitly mentioned in most design codes. To carry out routine design and checking, it is necessary to reliably estimate the soil restraint effect on the pile for a given site. However, the existing design methods of piles do not consider the influence of soil restraint to piles with different slenderness ratio as the piles are designed as a beam-column, thus limiting the pile to take up more load than it should. In this study, a finite element software PLAXIS 2D is used to carry out a parametric analysis on the effect of soil restraint to long slender pile in different soil conditions and slenderness ratio. A simplified estimation method based on Euler’s buckling theory is provided for predicting critical buckling load of pile. Results are discussed in this paper.

Ismacahyadi Bagus Mohamed Jais, Diana Che Lat, Abubakar Ibrahim Alasan, Fairul Zahri Mohamad Abas
Physicochemical and Engineering Properties of Coal Bottom and Fly Ash Mixtures Modified with Poly-Vinyl Alcohol and Sodium Lauryl Sulfate

Re-using bottom ash (BA) and fly ash (FA) can decrease disposal volumes and cost while also reducing dependence on non-renewable resources for sustainable aims in geotechnical applications. This study investigated the modification of the physicochemical and engineering properties of coal bottom and fly ash (BFA) with poly-vinyl alcohol (PVA) and sodium lauryl sulfate (SLS) at concentrations ranging from 1.5 to 2.5%. The different mixture ratios were denoted as BA100, BA60 FA40, BA40 FA60, and FA100. The proportion of BA40 FA60 modified with SLS at a concentration of 2.5% yielded a mildly alkaline pH with a distinct surface morphology consisting of well-distributed, smooth, and fine particles. The modification by using PVA and SLS generated high maximum dry density, high optimum moisture content, and improved unconfined compressive strength values ranging from 8.36 to 22.14% as compared to unmodified specimens after a 28-day curing period. These results were attributed to PVA/SLS–coal ash electrostatic physical bonding. Lower permeabilities over time of similar mixtures were recorded, ranging from 5.22 × 10–4 to 5.29 × 10–4 cm s−1 in SLS solution concentrations ranging from 1.5 to 2.5%. These coal ash wastes showed no unique changes in terms of the variation of main oxide content and crystalline phase for alteration concentrations for both modifiers’ solutions. These findings indicate that the physicochemical and engineering properties can be strengthened via a modification process achieved by inducing the novel stability of electrostatic suspension. In turn, this can actively interact with other matrices, such as those intended for soil as well as polymer or composite materials.

Afizah Ayob, Crystal Gayle’s Robert, Hamizah Mokhtar, Mustaqqim Abdul Rahim, Senja Rum Harnaeni, Munif Bahatin, Farahiyah Abdul Rahman, Shahrul Azwan Shakrani, Dayang Siti Hazimah Ali
Correlation Study of Landfill Leachate Concentration and Resistivity Value for Prediction of Landfill Leachate in Shallow Groundwater

Electrical resistivity imaging (ERI) is being applied to hydrogeological applications studies like survey of groundwater contamination. Monitoring of groundwater using this approach was more effective because it does not use wells for observation. Among the purposes of this research were to determine the leachate and sand characteristics, evaluate the resistivity for different types of permeating fluids and measure the resistivity correlation between water and leachate. Due to the infiltration of leachate, the bad impact at the landfill site has been declared will give contribution to groundwater contamination. Methods that have been implemented was soil box method. The purpose of this method is to measure the electrical resistivity of permeates liquid and sand sample. The moist fine sand was placed into an oven of 100 °C for 24 h to obtain the dried fine sand oven. Various materials have been tested such as leachate, tap water, and distilled water for 15, 30, and 45 ml with dried fine sand oven. Characteristics of leachates were determined from dissolved solid determination, turbidity measurement, colour measurement, and more. It can be summarized that the resistivity value of leachate is lower than that of tap water and distilled water. Also, from the comparison it can be concluded that leachate gives minimal impact for turbidity value as soil itself has a great effect on increasing the value of turbidity.

M. N. Kamarulzaman, M. H. Zawawi, A. Ahmad, M. A. Mazlan, N. H. Hassan, M. A. Kamaruddin
Centrifuge Modeling of Rockfalls with Different Slope Surface Materials using the MPS Method

Rockfall, one of the common natural catastrophes, complicates the phenomena due to a mix of inherent predisposing variables and external factors such as slope surface material constants. In this study, aiming to investigate effects on the behavior of rockfall of parameters, a 50 G centrifuge experiment is implemented with two 45° inclined slope surfaces of different materials, two of which are different in hardness, and two aluminum cubes of different sizes, which are recorded by four high-speed cameras. The moving particle semi-implicit (MPS) method is a type of particle method that discretizes a continuum by using computation points as particles that move with the physical quantity with meshless and has attracted much attention because it is easier to model the object of analysis and can easily handle large deformation and fracture. From the perspective of verification and validation (V&V), the MPS method is employed to validate the results based on centrifuge experiments.

Gaoyuan Lyu, Akihiko Hirook, Makoto Tobo, Toshiyuki Ozaki
Bearing Capacity of Deep Foundation Socketed into Granitic Rock

With advancements in drilling techniques and improved coring tools, deep foundations socketed into granitic rock have been widely used to support the heavy loads imposed by the high-rise buildings and bridges. To optimize the pile design, designers are often required to estimate the pile’s bearing capacity and subsequently validate the design parameters with pile load tests. Most of the time, the pile’s bearing capacity is calculated based on empirical models suggested by various researchers around the world. However, these equations may not be suitable, as the data used to derive them were based on the pile load tests carried out at various location, likely with different construction methodologies. This paper aims to develop an empirical model to estimate the pile shaft resistance in granitic rock based on uniaxial compressive strength (UCS) by using data from twelve pile load test results performed in Southeast Asia and three pile load test results carried out in East Asia. Thirteen of the piles tested by using bi-directional static load test (BDSLT) method and remaining tested by conventional top-down static load test method (SLT). Comparison between the actual test data and estimated capacity by using existing empirical models is also presented. This paper also further demonstrates the maximum displacement of pile shaft segment in rock upon reaching failure. For pile shaft resistance not reaching its ultimate value, a suitable method is applied to predict the ultimate shaft resistance values. End bearing capacity obtained from the pile tests is also presented herein as reference.

Yong Ping Oh, Mohd Ashraf Mohamad Ismail
Ground Improvement Techniques for Soft Soil

A large number of ground improvement methods are available that can be adopted to treat poor soil site conditions. Several of these methods have been in use for many decades, while others have been recently developed. The selection of the most appropriate ground improvement method can be a complex process that depends upon the consideration of available techniques and a number of performance-specific and site-specific factors. Ground improvement using prefabricated vertical drain (PVD) with surcharge loading is one of the effective systems to accelerate the removal of excess pore water pressure in saturated soft clay prone to excessive settlement. The main ground improvement techniques and the key components of surcharge preloading with PVD are discussed.

S. Sharmeelee, F. Ahmad
Slope Stability of Sg Langat Under the Influence of Extreme Rainfall

This study aims to determine the geotechnical characteristics and behavior of soils in Sg Langat with different angles of slopes, the effectiveness of groundwater situations, and the effect of heavy rainfall on slope failure through numerical modeling. Critical slope failures happen during or after rain. Landslides, a natural disaster associated with sliding, are one of the catastrophes that can lead to the loss of lives. Thus, a study and analysis about the effect of extreme rainwater on slope strength is done to estimate the stability of slopes according to the extreme rainfall. This study is substantially to probe the effect of rainfall infiltration on slope stability with a shear strength of unsaturated soil and to determine the factor of safety of the unsaturated soil slope affected by rainfall intensity and different boundary conditions through numerical modeling. This analysis is performed by using GeoStudio software to imitate the soil characteristics and the behavior, with the given data of rainfall in a certain area. This review presents the numerical analysis of different slopes regarding former cases that are subordinated to extreme rainfall from different places. It is shown that Channel 2 has higher pore-water pressure than Channels 1 and 3, where phase 2 attained a higher pore-water pressure value of 78.08 kPa, whereas phase 1 reaches 67.95 kPa of pore-water pressure. In Channel 3, the factor of safety shown is the highest among all the channels which are 0.63, 0.88, and 1.11 for minimum, intermediate, and maximum values, respectively. The pros and cons of the numerical approaches are discussed and come with some general modeling recommendations.

Jeffery Nazrien Ng, Aizat Mohd Taib, Norinah Abd. Rahman, Wan Hanna Melini Wan Mohtar, Othman A. Karim, Muhamad Razuhanafi Mat Yazid, Safari Mat Desa, Suriyani Awang, Mohd Syazwan Faisal Mohd
A Review on Simplified Image Analysis Method for Measuring LNAPL Saturation Under Groundwater Table Fluctuation

The leaking from surface spills and underground storage tanks of various light non-aqueous phase liquids (LNAPLs) caused hazardous contamination to the subsurface system, especially in case of groundwater table fluctuations. The toxicity of these compounds has made infeasible field studies and gets a replacement with laboratory studies. Researchers have recently become very interested in using image analysis techniques to measure the saturation migration of groundwater and LNAPLs. Over the last decade, the simplified image analysis method (SIAM) has become increasingly popular. SIAM has been proved to be a suitable and effective tool for characterization and measuring LNAPL migration in the subsurface system. This research introduces a review of the recent studies and published on the simplified image analysis method for LNAPL migration measurements. The experimental approaches in this study can be viewed as an important intermediary between column studies and tank studies. Besides discussion on the research efforts, recommendations for future research are provided.

Doaa F. Almaliki, Harris Ramli
Modeling of Monopile for Onshore Wind Turbines Tower by COMSOL Multiphysics

This paper presents a study of a wind tower foundation subjected to wind loading, accomplish by using COMSOL Multiphysics. The restriction of the program is discussed with the way, in which the soil and monopile are modeled. The aim of this paper is to examine multiple monopile structure comparisons, and the problem of geotechnical engineering loads via numerical models. The computer codes are briefly described, and the numerical model is made between the results obtained from the FEM methods. Numerical methods in geotechnical engineering loads applied to the model comprise various wind turbines tower, with two different soil types. Foundation displacement, stress distribution, and total displacement at critical sections underestimate design load/stress were compared. Generally, this research looks at the virtual loads on surface of monopile on top part of monopile and the body load of foundation by applied Mohr–Coulomb in numerical model as well as similar results are found using the program for these cases, except for the wind loads predicted. Additionally, the impact of the mechanical characteristics of the adjacent soft clay and loose sand soil on the load pattern was as well investigated, together with the angle of internal friction and the cohesion of soft clay and loose sand. The outcomes of this paper may possibly be used as standards and recommendations for accomplishing a satisfactory design of monopile for onshore wind turbines tower.

Ahmed B. Shaath, Harris Ramli
Review of Natural Fiber Application for Sustainable Ground Improvement

Ground modification refers to a variety of processes for enhancing the engineering characteristics of the ground. It works in several soil types, including collapsible, expansive, soft, and mechanically deficient soils. Strips, bars, sheets, membranes, and fibers are examples of reinforcing materials that can help to strengthen the ground. Natural fiber materials, rather than synthetic ones, have recently gained appeal in sustainable geotechnics as a soil reinforcement strategy. Cost, mass availability, and environmental friendliness are all advantages of natural fibers versus synthetic fibers. Natural fibers, on the other hand, differ fundamentally from synthetic fibers, and fiber-reinforced soil’s behavior is influenced by both physical and features. In the present review, the brief history, characterization, and properties of natural fiber material are extensively discussed. Review also attempts to explore the advantage and disadvantage of natural fiber material. The degradation mechanism and the treatment method are also presented. As well as the soil reinforcement application, review on the application of geosynthetic and natural fiber as reinforcement in the foundation bed under different loading conditions is presented. Based on the detailed literature review, this paper lay out identified research gaps and present future direction for research.

Noor S. Al-Hassnawi, Fauziah Ahmad, Mohammed Y. Fattah, Mastura Azmi
Physical Properties of Soil and Its Correlation with River Bank Erosion and Soil Erodibility: Sungai Pusu Case Study

Riverbank erosion is a complex process where the extent of riverbank erosion is influenced by many factors including soil properties. In this study, soil samples were collected from different sections of riverbanks at Sungai Pusu. Several physical soil properties such as the median grain size, percentage of sand, silt and clay, plasticity index, and specific gravity were measured for each soil samples. Riverbank erosion rates were measured at the site periodically using erosion pin method. Linear regression was conducted to identify the correlation between the erosion rate and the physical soil properties using the Statistical Package for the Social Science (SPSS) software. It was found that the percentage of sand content had significantly influenced the erosion rate, while the other parameters showed weak correlation and no correlation with the erosion rate. Soil erodibility coefficient, kd, was calculated using empirical equation, and the value ranged between 0.0553 and 0.1023 cm3/N s. The erodibility of the soil samples can be categorized as “Moderately resistant” based on the τc versus kd plot produced by previous study.

Nur Aqilah Mohd Rosli, Saerahany Legori Ibrahim
Quick Review of the Approaches of Landslide Risk Assessment

Landslide prevention and mitigation have a long history. Retaining walls and ground anchors are popular methods for preventing slope failure, as these prevention methods increase the factor of safety against failure. These methods are widely utilised and proven to be effective all around the world. The methods are however very costly, leading to a restricted application only for wide slopes. A landslide early warning system (LEWS) with real-time monitoring system is required to identify appropriate moment for preventive measures in order to handle landslide emergencies. However, depending on the type of landslide, different techniques are required. The approach is frequently used to help determine a set of crucial thresholds that can be used to determine when alerts can be sent, and it is based on LEWS’ own theoretical basis. This paper presents a quick review on the three general approaches used in LEWS, namely statistical approach, physical-based approach and monitoring-based approach. This quick review will attempt in discovering more on the strengths and advantages rather than diving into the limitations of each approach.

Mohamad Firdaus Mahamad Yusob, Fauziah Ahmad, Mohd Fadzil Ain, Mastura Azmi
Evaluation of Slope Stability Due to Earthquake and Rainfall Occurrences

Malaysia is a tropical country with high humidity, heavy rainfall, and unfrequent earthquake, while tremors can exist due to neighbouring regions earthquakes such as Sumatra. The 2004 Sumatera earthquake caused 68 death in Penang, Langkawi, and Kedah. The combined effect of rainfall and earthquake is unknown for the existing slope structures in Penang Island. The research presents the results on slope stability after the impact of rainfall and earthquake using the GeoStudio software. In the first step, the single effect of rainfall shows that longer duration and higher intensity adversely affect slope stability. However, the safety factor was lower when both effects of rainfall and earthquake were considered in the analysis. The combined effect was assessed through two factors of FOS and deformation since the seismic waves imposed as secondary damage to the hill. The results show that higher deformation is recorded for slope geometry with a bigger angle and higher height. The slope is classified as a failed candidate when the factor of safety is less than 1.0. The slope geometry in Sungai Ara was relatively unstable, and the factor of safety (FOS) has not complied with Penang safety guidelines for hill site development 2020. Various slope reinforcement procedures are mainly discussed in relation to Sungai Ara’s slope to improve the slope stability and lead to a higher factor of safety. The research proposes several reinforcement approaches, including retaining walls, soil nailing, and a drainage system. The results demonstrated that the factor of safety improved, and seismic waves deformation reduced, which proved the capability of reinforcement approaches in reducing the effect of rainfall and earthquake.

Goh Chin Sin, Mastura Azmi, Mazdak Ghasemi Tootkaboni

Sustainable Infrastructure

Comparison of Microstructural Properties of One- and Two-Part Fly Ash Geopolymer Concretes

Geopolymerization is a chemical process involving reacting raw aluminosilicate minerals with alkali activators such as sodium hydroxide and potassium hydroxide to produce a geopolymer binder. In most cases, anhydrous activator is typically made by dilution with water to form a liquid activator before being blended with other raw components such as sand and coarse aggregates. This traditional approach, also known as two-part mixing, can be hazardous due to the corrosive nature of the liquid activator, making it difficult to mix huge volumes of concrete. In recent years, a one-part mix or “just add water” geopolymer concrete has been proposed as a simpler mixing method to minimize mixing time and improve the perception of geopolymer concretes. Similar to the preparation of typical Portland cement concretes, a one-part mix is performed in which all of the dry ingredients, including the solid activator, are initially combined together before water is eventually added to the mix. As a result, the aim of the research is to compare these two geopolymer concrete types, as well as how these mixing processes affect the mechanical strength and microstructural properties of fly ash geopolymer concretes. This study also compares the effects of the activators used, which included sodium hydroxide (NaOH) and potassium hydroxide (KOH). Microstructural investigation was performed through Fourier transform infrared (FTIR) and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM–EDX). It was observed that one-part geopolymer concrete using NaOH as activator shows higher mechanical strength. The fly ash geopolymer binder study reveals that sodium aluminosilicate hydrate (N-A-S–H) gels and potassium aluminosilicate hydrate (K-A-S–H) gels are the binding gels formed in one-part and two-part mixing methods at different alkali activators with the formation of N-A-S–H gels which is faster with NaOH activator than with KOH. It may be inferred that one-part geopolymer concretes perform better than two-part geopolymer concrete mixtures, and that NaOH-activated concretes exhibit more desired characteristics than KOH-activated concretes. It can be concluded that one-part geopolymer concretes perform better compared to two-part mix of geopolymer concretes and NaOH-activated concretes gives desirable properties compared than KOH.

Nurulhuda Nadziri, Idawati Ismail, Amirul Syahmi bin Ardi, Nurul Hadirah binti Damni, Annisa Jamali
Strength Performance of Hybrid Fiber-Reinforced Concrete Containing Manufactured Polypropylene and Ring- Shaped Polyethylene Terephthalate Waste Fibers

Fibers are basically utilized as substitutes for ordinary support in nonprimary applications to control early warm withdrawal and drying shrinkage breaking. However, polypropylene (PP), lamellar or straight fibers are weak interfacial bond strength of surface during fiber bridge stress. Therefore, to solve the limitations of traditional straight or irregularly PP fibers, ring-shaped poly-ethylene terephthalate fibers were promoted as combination fiber with manufactured PP fiber in concrete. This study aims to determine the slump flow, density, compressive strength, tensile strength and water absorption of hybrid fiber-reinforced concrete (FRC) containing manufactured PP and ring-shaped PET fiber. An experiment was conducted in fresh and mechanical properties of PP and ring-shaped PET fibers with the percentage of 0%, 0.5%, 1.0% and 1.5% for both fibers. The results of fresh FRC properties showed maximum values for mix control samples, while the minimum values for slump flow test was recorded with 1.5% of PP and 1.5% of ring-shaped PET which is 3.2% less than control sample. Meanwhile, density after 28 days curing was increased 5.8% than control samples with 0% of PP and 1.0% of ring-shaped PET. However, 1.0% of both PP and ring-shaped PET fibers achieved 6 and 22% increment for FRC compressive strength and splitting tensile strength, respectively. In conclusion, the fresh properties of concrete were decreased with incorporation of PP and ring-shaped PET fibers while hardened properties were improved.

Faisal Sheikh Khalid, Abdullah Nabil Abdullah Al-Jaberi, Shahiron Shahidan, Mohd Irwan Juki, Syafiqa Ayob
Thermo-Mechanical Properties of Concrete Mortar with Cenosphere

Materials used in modern constructions received attention from researchers and engineers recently due to their impact on climate change, power consumption and operational cost. The usage of recycled materials gives extra advantages towards environment. It was found that power plant produced various types of waste product that can be utilize in many applications. For instance, Cenosphere produced as waste product from power plant have ability promotes thermo-mechanical properties of mortar to certain extents. Synthetic fibers such as Polypropylene (PP) was added to increase mechanical properties of mortar as well as thermal value. The aim of this study is to evaluate the effect of cenosphere and PP fiber added to concrete mortar on its mechanical properties and thermal conductivity at different compositions (0, 5, 10, 15 and 20%). Five separate mixes were tested in this report. The findings for mechanical properties tests suggested that the usage of cenosphere as sand replacement has significantly reduce the mechanical strength as well as density of samples. Twenty percentage of cenosphere caused the compressive and tensile strength together with density reduced to lowest value which are 8.6 MPa, 8.20 MPa and 1416 kg/m3, respectively, as compared to other percentages. This study also revealed that k value reduced as low as 0.62 W/m K due to incorporation of cenospheres and mixtures. It can be concluded that higher percentage of cenosphere used in mortar samples, thermo-mechanical value decreases.

S. Beddu, N. A. N. Basri, Z. Itam, N. L. Mohd Kamal, T. S. Manan, Z. Che Muda, D. Mohamad, N. Sivakumar, Agusril, K. X. Lee
Influence of Moisture Content and Position on the Tensile Strength of Four Air-Dried Bamboo Species

Bamboo is one of the fastest growing plants globally, and it has been used for numerous applications, including in the construction industry. It also has been known that bamboo has an excellent mechanical property, especially in tensile. However, each species has different mechanical properties, and generally, moisture content and the bamboo position have a greater impact on the variation of bamboo properties along with the culm height. Thus, this study focuses on the effect of four bamboo species’ moisture content and position: Dendrocalamus asper, Bambusa vulgaris, Gigantochloa scortechinii, and Shizostachyum grande. The test on the bamboo was conducted after the treatment and air-dried conditioning were completed. The moisture content test and tensile strength test were conducted for each species for 1, 5, and 7 months. The results show that the D. asper and B. vulgaris have the highest tensile strength value, followed by G. scortechinii and S. grande. Moreover, it was observed that the tensile strength of bamboo increased from the bottom to the top part of the bamboo. The moisture content of each species also differs, and the value also increased from the bottom to the top part of the bamboo. The moisture content decreased from 1 to 7 months while the tensile strength increased. It was concluded that the tensile strength of bamboo differs from each species and position, as well as the change in moisture content affects the tensile strength.

Dinie Awalluddin, Mohd Azreen Mohd Ariffin, Yusof Ahmad, Nor Fazlin Zamri
The Aflaj Systems in Sultanate of Oman: Its Traditional-Engineer Construction and Operation

The ancient aflaj (singular falaj) system in Sultanate of Oman is not only an irrigation system conveys rainfall accumulated water-table (from aquifer) to the settlement areas, but also it hold a unique construction method since millennium. It is believed that the location of Oman, in an arid or semi-arid climate surrounding with harsh desert environment, has led the settlers to develop high experience in the art of water exploitation. Much were written in descripting these systems using Iranian qanat system. Because of a confusion found in describing the construction of the three main component (mother-well, shift and tunnel), this paper used author own knowledge in the aim to clarify such confusion. This knowledge has been gained and collected from the continuous contact with local and the use of wide range of literatures in the purpose to offer contribution in systematic manner with regard to the traditional engineer construction process. The finding clearly showed the Omani construction method for the aflaj hold its own way with accordance to the experiences of the local people.

Ahmed S. Al-Marshoudi, Jasni Sulong
Environmental Benefits of Sustainable Green Buildings (SGBs): A Project Life Cycle Perspective

Green building technology is one of several sustainability practices and technologies that have been developed with the goal of achieving environmental sustainability. The benefits of establishing sustainable green buildings (SGBs) are numerous and mirror various parts of the building’s life cycle. One of the most significant variables that benefit from the development of SGBs is the environmental factor. There is various research in the area of SGBs but less focus is given on the environmental benefits of SGBs during their life cycle stages. This study intends to identify the environmental benefits of SGBs throughout their life cycle, based on the results of the in-depth semi-structured interviews with 25 professionals in the field of the built environment of Jordan in order to accelerate the adoption of this new building technology. The result of this research was obtained by the content analysis of data using Atlas ti software. The outcomes of this study shows that SGBs have several environmental advantages throughout their life cycle. The main environmental benefit in the design stage was related to “Innovative environmental solutions,” while the major environmental benefit in the construction stage was regarding “Conservation of resources and environment,” followed by the operational stage that was linked to “Decrease harmful environmental impacts of buildings”. Lastly, the most significant environmental benefit in the maintenance stage was concerning “Preserving the environment.” The importance of this research rests in the significant addition it will make to the literature in this field, and the relevance of green building technology adoption as an important topic in the construction industry.

Sharifah Akmam Syed Zakaria, Farah Hussain Saaed Ahram
Light-Rail Transit (LRT) in Penang: LRT’s Route Selection and the Impact Toward Neighborhood in Penang

Penang now is preparing and getting ready to achieve the state development vision under Penang’s 2030 agenda, A Family-Focused Green and Smart State that Inspires the Nation. Penang’s mobility and connectivity infrastructure are to undergo a major overhaul through public and private sector investments. One of the focuses is to strengthen mobility, connectivity, and digital infrastructure by improving public transportation infrastructure. This study was carried out to investigate the criteria that have been considered in selecting Penang Light-Rail Transit (LRT) route and the impacts on the neighborhood. An in-depth interview session with professional experts who have been involved directly with the project has been carried out to shed some light on this issue which gained a popular topic of discussion ever since it was announced by the Penang State Government. The findings show that four criteria were taken into consideration during the routing selection process: accessibility, finances, environment, and population. A point to highlight, the safety aspect is the least to be considered in Penang Light-Rail Transit (LRT) routing. But when it comes to impact, the proposed LRT routes become one of the environmental pollution issues such as noise and vibration. Even though there are drawbacks related to the proposed infrastructure causing major disruptions in the state, however, the LRT corridor’s potential benefits may offset these disadvantages. The findings from this study will definitely stimulate further discussion and debate.

Siti Nadia Kamarudin, Ernawati Mustafa Kamal, Muneera Esa
The Relation Between Destructive and Non-destructive Test of Concrete Incorporated with Dredged Sediment as Fine Aggregate Replacement

Accumulation of dredged sediment due to uncontrolled land clearing, construction works, agricultural activities, river control works, soil mining and dam construction at the upstream has led to an environmental issue in Malaysia. Sungai Pusu and its tributaries which is located at Gombak, Selangor Darul Ehsan, has been identified as the affected river that transports the excessive sediment to the stream. Part of Sungai Pusu area is situated within the International Islamic University Malaysia (IIUM) boundary. Due to the construction work at the upstream of the river have contributed to the accumulation of dredged sediments resulting in the disturbance of the river ecosystem. This study has been conducted to analyze the properties of dredged sediment as a replacement for fine aggregate in concrete. The dredged sediment that was used was taken near IIUM Gombak. Basically, the quality and strength of the dredged sediments were investigated using destructive and non-destructive test analysis. For destructive test, compressive strength test was carried out, meanwhile for non-destructive test, we conducted rebound hammer and ultrasonic pulse velocity test followed by the analysis. The compression test reveals that all of the samples have achieved strength greater than 30 MPa which is the minimum strength specified in this test. At the same time, the rebound hammer test result showed that the estimated compressive strength for all samples has also achieved the specified strength with the difference of all estimated and actual compressive strength which is less than 10%. The result followed by UPV test yields a fast pulse velocity indicating a good quality concrete for the samples. All of the results showed that the replacement of 25% of dredged sediment produced the best result on the 28th day of curing compared to other mixture. Overall, all of the tests that were done on this project show that the fine aggregate can potentially be replaced by the dredged sediment in the production of the concrete.

Siti Aliyyah Masjuki, Nurul Ibrah Mat Gheni, Altamashuddinkhan Nadimalla, Siti Asmahani Saad, Nadiah Md. Husain, Siti Noratikah Che Deraman, Saerahany Legori Ibrahim, Nur Khairiyah Basri, Shuhairy Norhisham

Transportation and Traffic Engineering

Review on the Main Characteristics of Freeway Merging Section

The merging section is considered an essential part of the freeway segment, and it is one of the causes of traffic congestion along the freeway. This study reviews the main characteristics of merging sections and the methods to reduce traffic congestion at the merging section. Several significant factors affecting the merging section were identified such as freeway capacity, length of merging section, speed, traffic volume, and traffic composition. The effect of these factors has been thoroughly reviewed in this study to investigate their influences on traffic operations at merging sections. The effectiveness of ramp metering (RM) and gap metering (GM) was also reviewed in this study. The results indicated a significant impact of some traffic characteristics at merging sections, such as the lane-changing behavior, heavy vehicles, and RM effect. Combined with RM, the gap metering mechanism can reduce the overall delay at merging sections up to 27% compared to RM alone.

Wafaa Kh. Luaibi, Lee Vien Leong, Hamid Athab Al-Jameel
Cooling Behaviour and Reusability of Hot Mix Asphalt

Temperature is the most important element that can affect the performance of hot mix asphalt. There is a large amount of discarded asphalt mixture waste after construction due to the cooling phenomenon when exposed to surroundings. This study investigates the cooling rate of the AC14 mixture and the reusability of hot mix asphalt after reheating and compacting at various temperatures. In this study, the cooling behaviour of the loose asphalt mixture was monitored by measuring the surface temperature, the internal temperature of the mixture and the surrounding conditions. The cooling curve, cooling rate, and TAC were determined based on the results obtained. Other than that, for the reusability of hot mix asphalt, five different types of samples were prepared with a different number of reheating processes and compaction temperatures. The compacted samples were tested for volumetric properties and the Marshall stability test. The result determined the surface and internal TAC at 32 and 40 min, respectively. It was also found that reheating the cold mixture twice and compacting it at a considerably high temperature could achieve the required properties. Therefore, further studies should be conducted using large-scale samples to verify the finding.

Aidiel Ashraf Abdul Razak, Norhidayah Abdul Hassan, Munzir Abdullah Zawawi, Mohd Zul Hanif Mahmud, Nordiana Mashros, Azman Mohamed
Road Crashes Among Food Delivery Riders (P-Hailing) During Pandemic in Kuala Lumpur

Due to COVID-19 outbreak in Malaysia, a movement control order was implemented on March 18, 2020. As a result, many people ordered food through food delivery services, which may have come at a high cost due to the recent spike in food deliveries. This study aims to establish the causes and the most frequent mentioned elements that contribute to road crashes among riders. Road accidents are a severe concern since they result in death or injury, yet the number of fatalities among riders continue to rise. The study was done in the vicinity of Kuala Lumpur and the data was gathered through a survey using online Google Form questionnaire. The instrument was measured using a reliability test and exploratory factor analysis (EFA) to generate an empirical verification of the questionnaire’s validity and reliability. Then, a descriptive analysis was undertaken for each variable to determine the primary factor. As a result, the critical fact resulted in cell phone use while travelling on the highway was a human factor component. The study’s findings drew more attention to the issue and raised awareness about road safety.

Ahmad Raqib Ab Ghani, Al Insyirah Abd Malek, Wan Azfizatul Az Zarah Wan Mohamad Yusoff, Nik Shahidah Afifi Md Taujuddin, Kamarudin Ambak
Characterization of Penetration Grade Bitumen Blended with Petroleum Products for Cutback Production

Cutback bitumen is a potential binder that can be used for producing cold mix asphalt. This study presents the characteristic of produced cutback bitumen according to different types of diluent used. The 60/70 penetration grade bitumen was mixed with different petroleum solvents (gasoline, kerosene, and diesel) to produce cutback bitumen for potential usage in asphalt pavement. The binder’s viscosity and evaporation rate (curing time of solvent) were investigated to select the appropriate percentage of solvent that provides lower mixing and compacting temperature range. The percentage of diluent was varied at 30, 35, 40, and 45%. The viscosity was measured at a temperature ranging from 30 to 70 °C with an increment of 10 °C, while the evaporation rate was measured at an ambient temperature. The results show that the viscosity of each blended bitumen decreases as the percentage of diluent in the mix increases. The evaporation rate of the solvent is higher for gasoline and kerosene than diesel due to the volatility and chemical compositions of the solvents. From the data obtained, the most effective percentage of solvent for the cutback production is 40–45% by weight of the penetration grade bitumen, which establishes the lowest potential mixing and compacting temperature range for the asphalt.

Nurul Tasnim Che Noh, Norhidayah Abdul Hassan, Abdullah Farhan Nasralddin, Muhammad Naqiuddin Mohd Warid, Mohd Zul Hanif Mahmud, Mohd Khairul Idham Mohd Satar
Uncovering the Risky Riding Behaviors Among Young Motorcyclist in Urban Areas

In Malaysia, more than 50% of road traffic crashes involve motorcyclists, with motorcyclists being the main contributor to the road crashes. Thus, the traffic safety of motorcyclists is critical and must be given priority. Road traffic crashes showed a significant increase every year in Malaysia according to Department of Road Transport statistics. Numerous researches on the relationship between risky riding behaviours and traffic accidents have been identified; however, research focuses on young motorcyclists’ risky riding behaviors in urban areas were somewhat limited. To demonstrate that risky riding behaviors which played a significant role in the number of motorcycle crashes among motorcyclists, a motorcycle-riding behavior questionnaire was distributed to groups of young motorcyclists in several schools and higher education institutions to assess their level of understanding and perception of risky riding behavior. Two primary analyses, namely frequency and percentage, cross-tabulation, and test of independence (chi-squared), were adopted to assess their level of understanding on motorcyclists’ risky riding behaviors and its correlation to crashes. Findings have proven that failing to keep proper side-to-side movement with another vehicle and riding while tailgating with another vehicle at an unsafe distance were highly contributed to the motorcycle crashes among the secondary school students. A greater comprehension of motorcyclists’ risky riding behavior based on their self-reported behaviour and beliefs can influence motorcyclists to make positive changes in their riding style. Hence, this result will be beneficial for enforcement bodies to strategize their effort in curbing the crash issues involving riders.

Siti Zun Nurain binti Mohd Ali, Intan Suhana binti Mohd Razelan
How Drivers’ Physiological Response of Blood Pressure on Unsignalized Conventional Roundabout?

A roundabout is one of the components of a critical road network, which consists of a circular intersection with a smaller island in the middle. In Malaysia, the traffic that moves through this critical network usually moves in a clockwise direction, meaning that the priority of traffic would be given towards the vehicle inside the roundabout to move first. The focus of this research was to measure the physiological behaviour of each of the participants. By focusing on the inner side of the transportation system, which is the driver itself, we could build an innovation that would contribute to a better transportation system. The youth participants were those whose age was set at 20–30 years old. One of the accessible physiological behaviours of drivers is blood pressure, measured by using an OMRON Digital Wrist Blood Pressure Monitor. By studying these data, we could determine the way they conducted their driving approach during a real-life situation. Although various variables could affect their driving experience in real life in this study, the focus will be only on the blood pressure of drivers before, during, and after driving, including their driving speed. Analysis by using the regression method to obtain the r-squared value has been applied to determine the correlation level between both of the variables. By comparing the data of blood pressure of genders between entering, driving through, and exiting the roundabout, the highest R2 reading obtained was 0.8209 and 0.6779 for male and female drivers, respectively.

Shahrul Jainudin, Jezan Md Diah, Suria Haron, Sharifah Abdullah
Mobility Trend in Malaysia Throughout Restrictive Mobility Policies and National Immunization Programme Due to COVID-19 Pandemic

A study on the change in mobility amongst Malaysians during and post-restriction movement policies due to COVID-19 is needed, at the same time to understand the impact of the National Immunization Programme that was imposed by the government. A descriptive and comparative analysis was done for the percentage change in mobility of all states in Malaysia for retail and recreation, grocery and pharmacy, parks, transit stations, workplaces, and residential areas using Google Mobility Reports. Almost all the categories of mobility showed a decrease in percentage during 2020 due to the MCO, and the percentage for residential showed an increase as people were encouraged to just stay at home. In 2021, generally, the trend was an increase in all categories due to the ease of restriction and the proactive move by the government under the National Immunization Programme (NIP).

Surachai Airak, Nur Sabahiah Abdul Sukor
State-of-the-Art Review of Signalized Roundabouts: Evaluation, Analyses, and Gaps

One of the easiest and most economical methods to increase traffic flow across the metropolitan network and relieve congestion at junctions is to implement signalized roundabouts. In order to provide the most current findings, identify any remaining study gaps, and suggest potential paths for future studies in the area, this article reviews recent literature on signalized roundabouts, including various traffic signal types, published between 2010 and 2021. By finding the publications that made the short list on Google Scholar and Scopus, the most recent literature review was utilized. Both Google Scholar (n = 55) and Scopus (n = 156) have found a total of 156 linked publications. The most thorough micro-simulation program utilized for signalized roundabouts was therefore thoroughly examined in this paper. We conclude by making a few projections about the future direction of this study.

Amani Abdallah Ali Assolie, Nur Sabahiah Abdul Sukor, Ibrahim Khliefat
Gap Acceptance Behaviour of Risky Right-Turning Motorcyclists from Minor Roads at Conventional and Unconventional T-Junctions

Right turning from a minor road is the most critical movement at T-junction, and the risk of right-turning motorcyclists involved in an accident is extremely high because of their riding behaviour. This study was carried out at three types of T-junctions which are type-A (conventional T-junction), type-B (unconventional T-junction with short exit lane for right-turning minor road vehicles) and type-C (unconventional T-junction with short exit lane for through major road vehicles). Results indicated that type-A T-junction is the safest as it has a lower percentage of risky riding behaviour. However, motorcyclists at type-B T-junction behaved better as most of them only performed one risky behaviour (56%) or none (34%). Additionally, results showed that motorcyclists accepted a smaller gap of 1.639 s for forced entry than the usual gap of 7.262 s. For gap acceptance behaviour involving a motorcycle and car making a right turn together, the mean accepted gap for this behaviour was 9.318 s for type-A, 8.319 s for type-B and 8.758 s for type-C. In conclusion, the geometrical configuration of type-B T-junction provides the best performance as the motorcyclists are more well-behaved and record the smallest value of the mean accepted gap.

Lee Vien Leong, Hor Kuan Chan, Shafida Azwina Mohd Shafie
Intelligent Transport System and Image Processing: Developing Traffic Detection Program Based on Indonesian Highway Capacity Manual 1997 for Rural Road

It is important in this digitalization era to develop the intelligent transport system for the future transportation. This study aims to develop traffic detection program based on image processing and Indonesian Highway Capacity Manual 1997 for rural road. The methodology of this study uses Gaussian Mixture Model (GMM) method that base in image processing. This program will run of video input in the morning with 6 m height and 7 m, as well as video input in the afternoon with 6 m and 7 m height. The calculation results on the program will be compared with manual calculations to get the accuracy and percent error values. The highest accuracy results obtained in this program are 76.48% with an error value of 23.52% for video 6 m in the morning. For the lowest accuracy results found on the 7 m video in the afternoon with an accuracy of 43% with an error value of 57%, this caused by congested traffic during video capture.

Muchlisin Muchlisin, Nurtia Amandairst

Water Resources Engineering

Assessment of Water Security for a Sustainable Environment: An Indicator-Based Approach Applied in Penang, Malaysia

When risks to water security increase it is necessary to enhance the management response. Water and climate change are closely related as water form a channel through which the effect of climate change can be experienced. This study has applied an indicator-based approach to establish a framework for assessing water security performance in Penang, Malaysia. The framework is targeted at supporting current contributions in attaining sustainable water security in the state. Analysis of the region’s water security index was conducted and compared with international standards. The dimensions and indicators applied are based on the UN-water definition of water security, while the variables applied in the assessment were selected based on appropriate findings from the literature. A water security index ranging from a scale of 1–5 was obtained. The outcome of the assessment showed an overall good condition of water security in Penang with the potential to handle future changes for a sustainable and resilient environment. However, the findings have shown that there is room for improvement in water-related disasters, ecosystems preservation, and water governance to enhance the condition of water security in the state.

Rozi Abdullah, Rofiat Bunmi Mudashiru, Nuridah Sabtu
Land Cover Mapping Based on Open-Source Data and Software: Kelantan Area Case Study

Land cover map preparation is essential for catchment management, hydrological analysis, and flood mapping. The process of deriving accurate land cover maps is challenging and requires a certain level of skill and experience. Cloud cover and the heterogeneity of the area under consideration increase the challenge of classification, especially in tropical areas. Recently, a wide range of free digital data and open-source software have been developed and become easily accessible. Using these data and software will help overcome many of the obstacles related to data availability and analysis in the fields of environment and water resources. In this study, the construction of the land cover map of Kelantan State in Malaysia and the accuracy assessment were performed using open-source data, and software has been demonstrated. Open satellite maps and the QGIS software were used for analysis with an overall accuracy of 91.46%.

Raidan Maqtan, Faridah Othman, Wan Zurina Wan Jaafar, Ahmed Elshafie
Energy Consumption of Variable Speed Pumps Under Transient-State Condition in Water Distribution Networks

This article aims at drawing a comparison between the power consumption and cost incurred for variable speed pumps (VSPs) working under steady-state and transient-state conditions in a water distribution network. A 24-h variable water demand pattern was attached to a residential community water distribution network in EPANet 2.2 for simulation along with introducing a pipe leak at a critical node to assimilate the transient-state condition. It was observed that there was a significant difference in the energy consumption of VSPs working at lower and high speeds when compared with their nominal speed. The results show an energy cost cut of 40% at 15% lower speed and an energy cost hike of 50% at a 15% higher speed of VSP than its nominal speed. A mathematical relation is developed to estimate the energy cost difference at any speed of VSP working under the transient-state condition in a water distribution network.

Rehan Jamil, Hamidi Abdul Aziz, Mohamad Fared Murshed
Reliability of Rainwater Harvesting System Using Yield-After-Spillage Algorithm

Malaysia receives a lot of rain yearly, making rainwater harvesting system a high potential for usage in commercial buildings, industry and residential areas. The rainwater collected can be used for irrigation systems and as a source of indoor non-potable use. This study is conducted to test the reliability of rainwater harvesting system at Sultan Abdul Aziz Shah Airport in Subang, Selangor. The yield-after-spillage algorithm is used to perform the rain data analysis and calculation of reliability of rainwater harvesting system. The parameters analyzed in this study are annual rainfall pattern, roof surface area, storage tank size and rainwater demand. Generally, the result of the analysis shows that the reliability of rainwater harvesting system increases as the parameters of roof catchment area and tank capacity increase, but decreases when water demand increases. The maximum reliability is 51.1% for moderate water demand and 30.6% for high water demand during the year with average yearly rainfall. High reliability can be achieved with a minimum roof surface area value of 5000 m2 and tank size of 140 m3 for an average rainfall year. For moderate water demand, the increase in the reliability is less than 5% after exceeding 100 m3 tank size with roof surface area of 20,000 m2. For these specifications and by using the rainfall data from 1994 to 2014, at least 29.3% of the water can be supplied from the rainwater storage tank.

Nur Shazwani Muhammad, Mee Wai Lin
Multivariate Flood Damage Model: A Case Study of 2013 Kuantan Flood

Flood damage assessment is a crucial element to be considered in the implementation of efficient flood risk management. Hence, with the aim to examine the significant correlation between the impact and resistance parameters with the degree of flood damages, this study utilized the multiple linear regression (MLR) technique to develop a multivariate flood damage model of 2013 Kuantan flood. This study focuses on estimating flood damage in urban areas for residential and commercial buildings. The damage type assessed in this study is direct tangible damage which includes damage to buildings structure and its contents. The study’s findings revealed that socio-economy and property characteristics have also shown a significant correlation to the degree of flood damage. Flood depth was found to have a significant effect on all damage categories as in previous studies. However, in addition to flood depth, flood damage is also influenced by the value of properties, income, building material, building ownership status and type of properties. The MLR models validations are showing reasonable results compared with other studies with mean absolute error (MAE), root mean square error (RMSE), mean bias error (MBE), coefficient of variation (CV) which are closer to 0 and HR is close to 0.9.

Sumiliana Sulong, Noor Suraya Romali, AbdullahMukmin Ahmad
Performance Quantification of Flood Hydrograph Models Based on Catchment Morphometry Derived from 30 m SRTM DEM

Synthetic hydrograph unit (SUH) is one type of hydrological models for predicting floods at a watershed outlet. The accuracy of this model, apart from being dependent on the distribution and intensity of the rainfall, is also largely determined by the characteristics of the watershed, especially the area of the watershed and the configuration of the drainage network system. The characteristics of the watershed that can be described by morphometric and fractal properties, where the determination of which is very dependent on the resolution of the digital elevation model (DEM) data as the basis for derivation. This paper aims to evaluate the performance of SUH models based on catchment morphometry derived from Shuttle Radar Topography Mission (SRTM) DEM with a resolution of 30 m. This topographic elevation data is one of the free medium-resolution DEMs produced by the US National Geospatial-Intelligence Agency (NGA) and National Aeronautics and Space Administration (NASA). Two flood hydrograph models based on catchment morphometry—GAMA I and ITS-2—were evaluated by quantifying their performance using root mean squared error (RMSE) criteria. This performance indicator was measured based on predicted and measured unit hydrograph in one of sub-watersheds of Palu, Sulawesi, Indonesia, namely Bangga Catchment. Predicted unit hydrograph is interpreted from morphometric and fractal catchment parameters, while the observed unit hydrograph is derived from several flood hydrograph data. The evaluation results showed that the two hydrograph models that were examined showed very good performance with an RMSE below 1. This indicates that the 30 m SRTM DEM used to derive catchment parameters is still relatively good in defining the characteristics of the catchment. However, for applications to other catchments using the same DEM type, the rainfall characteristic must be carefully identified in order to represent the rainfall distribution pattern across the catchment.

I. Gede Tunas, Yassir Arafat, Rudi Herman
Determination of Downstream Hydraulics Geometry Parameters

The hydraulic geometry term represents the relation between the dynamic characteristics of a river stream and its discharge. The river characteristics quantitatively obtained by describing these parameters as power functions of discharge employing one coefficient and exponent. The aim of the study is determining the downstream hydraulic geometry parameters and to obtain a relation between flow discharge and sediment discharge with hydraulic geometry parameters of the channel. The depth, velocity, width, surface roughness and suspended sediment concentration data are collected at three selected stations along the channel. The results show that the downstream hydraulic geometry parameters for flow discharge relations b, f, m, p, a, c, k and N are discovered as 0.0417, 0.8889, 0.0789, 0.4580, 1.9842, 1.9710, 0.3693 and 1.8056, respectively. For sediment discharge relations, the hydraulic geometry parameters b, f, m, p, a, c, k and N are shown as − 0.0454, 0.9054, 0.3090, 0.1739, 1.1712, 2.1230, 0.3348 and 0.9325, respectively. The values of exponent and coefficient, (b, f, m, p, a, c, k and N) varies within some limits imposed more by ways the adjustment of stream power is dispersed across variables. This is because the scales parameters are varying and depends on the hydraulics parameters of channel. In addition, according to the results, the sediment and flow discharge relations at Station 1 were determined being more relevant than those at a different station when it comes to the correlation coefficient with average co coefficient and exponent of 0.75 and 0.25, respectively. Generally, the findings from this study are intended to be beneficial for manager and planner of water resources initiatives in the basin.

Zuliziana Suif, Mira Azmiza Azmi, Nordila Ahmad, Othman, Jestin Jelani
Computational Fluid Dynamic Analysis at Dam Spillway Due to Different Upstream Water Levels

This paper analyses the fluid dynamic on the dam spillway structure when the water spilling event occurred. The parameters determined in this study are velocity and pressure. A 3D Computational Fluid Dynamics (CFD) model of the dam spillway structure and the fluid boundary condition was developed using FLUENT. The result of the CFD model shows that hydrostatic pressure for all water levels was observed at the upstream section. The highest velocity and pressure occur at the highest water level which are 3.2 m/s and 1.526 MPa, respectively, at the spillway wall. High water velocity may contribute to critical stress due to the high pressure. All of the cases from 146 to 153 m water level show the fluid flows which are at reasonable velocity and pressure at the spillway. However, the continuous interaction with water towards the granite may affect the scouring effect of the granite in the long-term run.

N. H. Hassan, S. Z. A. S. Kamarulbahrin, M. H. Zawawi, A. Z. A. Mazlan, M. A. Abas, M. R. R. M. A. Zainol, M. A. Kamaruddin
Vibration Effect to Kenyir Dam Intake Section During a Spill Event

Kenyir Dam located in Terengganu, Malaysia is a hydropower dam which served the purpose of generating electricity to the surrounding areas. Water is basically flown from the upstream to downstream area through the intake and pressure tunnel sections. In some cases, due to large volume of water, the dam structure might experience significant vibration effect from water spill event. In this study, the flow-induced vibration during critical water spilling of 148 m water level at intake section of Kenyir Dam is investigated using ANSYS software. The results from both frequency domain and operational deflection shapes (ODS) are compared with the natural frequencies and mode shapes of the dam, in order to determine the safety precautions during dam operating condition. From the results of water level 148 m, the transient vibration response from the water flow is occurred at operating frequency of 2.745 Hz. There is no resonance phenomenon during this water spilling condition since the natural frequency of the intake section occurred at 3.5 Hz. However, some precautions should be taken since the deflection shapes of the dam structure might be higher above this water level.

N. H. Hassan, M. H. Zawawi, A. Z. A. Mazlan, A. Arbain, M. A. Abas
Numerical Study of Incompressible Flow Past a Circular Cylinder at Low Reynolds Number Using COMSOL Multiphysics

Incompressible turbulent flow past a stationary circular cylinder at Reynolds number of 10,000 was investigated using COMSOL Multiphysics in a two-dimensional simulation. At this Reynolds number, the flow pattern was in a transition from periodic to chaotic behaviour due to small eddies developing at the wall of the circular cylinder. The aim is to investigate a couple of turbulence models to predict the flow behaviour by comparing the result of vorticity patterns, drag and lift coefficients with the numerical result of previous researchers. This study employed two turbulence models, Spalart Allmaras and Menter’s Shear Stress Transport. Wall treatment and wall distance initialization options were also investigated. The SA model was able to give better result as compared to SST model when compared to standard drag coefficients values for circular object. The wall treatment was able to perform very well in determining how wall treatment should be treated, either using wall function or resolve the boundary layer with RANS depending on the maximum y+ that correlates with the mesh size on the wall of circular cylinder. The simulation with wall distance initialization turned off successfully imitates the result of previous research in terms of CD and CL curves pattern and wake pattern for the specific case of incompressible flow past a stationary circular cylinder.

Mohamad Faizal Ahmad, Mohd Ridza Mohd Haniffah, Ahmad Kueh, Erwan Hafizi Kasiman
Comparison of Water Velocity of Physical and Numerical Modelling Analysis on a Downscale Spillway

The study on the effect of velocity on the spillway was done conducted using physical and numerical model analysis. The 1:40 scale physical model was developed, where the velocity was measured in fourteen measurements points for three different velocity flows. Numerical modelling was analysed using Computational Fluid Dynamic (CFD) to compare the accuracy of the physical model analysis. Results from the study indicate that the maximum percentage difference between the physical model and numerical analysis in velocity values do not exceed 10% for all three cases. Point Q3 shows the highest value of velocity with 0.036 m/s for the physical model and 0.039 m/s for numerical modelling. The percentage of difference at point Q3 for numerical modelling and the physical model result is 7.69%. Meanwhile, points P5 and S5 indicate the lowest value of velocity, where the physical model and numerical modelling shows the same which is 0.006 m/s. The percentage of difference at points P9 and S5 for numerical modelling and the physical model result is 0.00%. It can be concluded that the velocity flow is higher at the energy dissipater parts compared to the stilling basin area due to the dispersion of water flow along the spillway.

F. Nurhikmah, M. H. Zawawi, N. H. Hassan, N. M. Zahari
Water Flow Velocity Analysis on Small-Scale Spillway Using Particle Image Velocimetry (PIV)

The spillway design for a dam project needs to deal with many hydraulics issues based on the study of the physical model. This study aims to investigate the flow characteristic and the effect of velocity along the spillway structure. The durability of the spillway structure was identifying by the area that experienced high velocity. In this study, twelve measurements points with three different velocity flow (0.025, 0.045 and 0.060 m/s) along the spillway were conducted. The scale-down physical model for the spillway was conducted for particle image velocimetry (PIV) analysis. Result from the study shows that the highest velocity value is at point Q3 on Case 3 which is 0.040 m/s and the lowest is at points P5 and S5 on Case 1 with 0.005 m/s. It can be concluded that the velocity flow is higher near the energy dissipater parts compared to the stilling basin area due to the water force acting on the spillway structure. To ensure the structural integrity sustainability, further study on the future mitigation measures can be taken.

F. Nurhikmah, M. H. Zawawi, N. H. Hassan, N. M. Zahari
Sustainable Infiltrated Drainage System with Porous Sublayer Modules

The main problem in the current urban drainage system is the inefficiency of the drainage system to accommodate high stormwater discharge in the system. This experimental study was aimed to investigate the effectiveness of porous sublayer modules in an infiltrated drainage system. Primarily, this chapter focused on the influence of different lengths of porous sublayer module on the infiltration, flow depth and velocity distributions in the drainage system. Laboratory experiments were carried out for three porous sublayer module lengths to drain diameter ratio ( $$Ls/d$$ L s / d ) of 0.7, 1.0 and 1.4 for two drain bed slopes and four drain section spacing. The study found that the optimum ( $$Ls/d$$ L s / d ) for 0.7 and 1.4 which allowed more than 75% of surface runoff to infiltrate into underground storage, as stated in MSMA for On-Site Detention. The flow velocity in the drain reduced by more than 80% with the application of porous sublayer modules. It was also found that the spacing between drain sections was a significant factor to lower the drain velocity. Its velocity increased as the water travelled further downstream and reduced as the drain spacing became larger.

Zulkiflee Ibrahim, Mazlin Jumain, Fenny Anak Baseng, Abdul Hadi Mohd Subki, Nor Zehan Hamzah, Ezat Faiz, Md Ridzuan Makhtar, Roslee Ishak, Nurfarhain Mohamed Rusli
Design of Individual On-Site Storage Pond for Supplementary Irrigation During Dry Period in Malaysia

Paddy and water are strongly connected to each other. In recent years, climate change has increased drought frequency, resulting in water scarcity in paddy sector in Malaysia. Therefore, in this study, a methodology was developed to design an individual on-site storage pond for supplementary irrigation purpose. The storage pond collects return flow from the paddy field for reuse purpose during dry season. First, the inflow discharge into the paddy field was estimated from field data. Field data was collected in both the main and off seasons. A simplified water balance model was then developed to estimate the amount of return flow from the paddy field, by utilizing the inflow discharge estimated from the field data. The return flow was used to design the individual on-site storage pond and both the inlet and outlet flow control structures. Results from this study showed that a simple methodology can be applied to design an individual on-site storage pond for water reuse purpose. This simple methodology can serve as a design guideline.

Nadiatul Amira Ab Ghani, Puay How Tion, Nor Azazi Zakaria, Nasehir Khan E. M. Yahaya
Application of GETFLOWS and HEC-RAS in Assessing Sediment Balance Within River Estuary

River plays an important role in the human need as it provides water for human usage, irrigation, agriculture and industry as well as a range of other ecosystem services other than intrinsic and biodiversity values. Managing the river can lead to many benefits and convenience. However, due to lack of proper management, rivers can be easily polluted due to human activities. Sediment is one of the components that can damage the ecosystem and diversity of the river especially in local spots which involves soil erosion. Heavy rainstorms can cause an excessive erosion event, however, most soil erosion happens gradually over time and is very hard to notice without constant monitoring. Furthermore, the sediment will be mobilized and transported along the river and eventually stored in the bottom of the river, but usually it will deposit near the estuary. A sediment modeling is needed to carter this problem as to predict the behavior of the sediment based on the hydrological components. The comparison between the 1D (HEC-RAS) and 3D (GETFLOWS) will be discussed in this paper to check the suitability and the validity of the model in sediment studies.

Siti Nurwajihah Abu Bakar, Abdul Hakim Salleh, Mu’izzah Mansor, Mohd Aminur Rashid Mohd Amiruddin Arumugam, Mohd Remy Rozainy Mohd Arif Zainol, Safari Mat Desa, Nasehir Khan E.M Yahaya, Fatehah Mohd Omar
Application of Computational Fluid Dynamics in an Outer Channel of Orbal Biological System

Orbal Biological System (OBS) is one of the modified oxidation ditches claimed as the most energy efficient, safest, and has the lowest maintenance. The OBS can be modified to meet a wide assortment of influence conditions and effluent requirements. There are three channels in OBS, outer channel, middle channel, and inner channel. The outer channel of OBS has the largest volume among the three channels, which is about 50% of the system’s total volume. It is crucial to study the operating system of the outer channel of OBS as it contributes to the highest energy consumption in the system. The computational fluid dynamics (CFD) model is developed to have a better picture of the OBS. The simulation in CFD was used to study the behaviour of the influence in the outer channel of OBS and the velocity distribution for different operating conditions in the outer channel of OBS. The result of the CFD model was used to study the relationship between the velocity and the number of aeration discs being used. This study shows that the volume fraction of water is higher at the bottom of the ditch, while the volume fraction of air is higher at the top surface of the ditch. This shows that the CFD model can represent the OBS in reality. From the model created, the velocity inside the ditch decreases when the water is deeper. The research provides a better understanding of the model flow behaviour of a biological treatment system using the simulation tool and can contribute to a better design of wastewater treatment process models in future.

N. M. Kamal, N. A. Saad, N. A. Zakaria, J. Abdullah, N. A. Azizan
Experimental Modal Analysis and Operational Deflection Shape Analysis for Kenyir Dam Spillway Physical Model

Kenyir Dam spillway physical model was developed to determine the vibration characteristics of the dam spillway due to different spilling events. This study focused on determining the natural frequency of the dam spillway in order to compare it with the mode shape due to spilling events. The physical model scale was 1:50 and similitude analysis using Froude law was used for scaling down purposes. There were 2 different water levels simulated for the experiment which were 2.92 and 2.96 m, and for each water level spilling, operational deflection shape (ODS) analysis was done for the spillway body. The most dominant mode shape was observed at the wall of the spillway at the downstream area. This mode shape corresponded to the natural frequency of 2801.1 Hz and cause an overall deflection amplitude of 0.353 m for a water level of 2.96 m. The numerical analysis was completed in order to compare the experimental result and it showed that the percentage differences for all parts were below 10%, which is generally below an allowable error percentage. The conclusion from this study was the experimental natural frequencies and mode shapes for all the parts show good agreement with the numerical analysis of vibration characteristics of Kenyir Dam spillway physical model.

N. H. Hassan, M. H. Zawawi, A. Z. A. Mazlan, M. A. Abas, M. R. R. M. A. Zainol, M. R. M. Radzi, M. A. Kamaruddin
Implication of Uncertainty in River Gauged Data and the Rating Curve Representations to Flood Quantiles: Case Studies from Stations Across Peninsular Malaysia

River discharge data are important in hydrological modeling and flood frequency analysis (FFA), e.g., in model tuning and determination of flood quantiles. A time series of river discharge is commonly generated from the application of a rating curve of gauged water level and discharge at a specific river cross-section. The curve fit using the data points inevitably comes with errors because of the imperfect knowledge on the stage and velocity measurements during individual gauge, for example, due to scour/fill, vegetation, and backwater effects. The errors challenge the reliability of a single rating curve over the governing dataset. This study aims to analyze how uncertainty in the rating curve generated from a complete record of gauged data can provide additional information in flood frequency studies when consider error bounds. A methodology was developed to tailor the aim of the study to the available data from stations across the Peninsular Malaysia. All river gauging stations in Peninsular Malaysia under the Department of Irrigation and Drainage (DID) databank were first examined and finally selected based on a set criteria (e.g., length of data availability and missing data). Uncertainty in the rating curve was represented by error distribution with upper and lower limit curves. A time series of discharges was then generated using the rating curves. Results show that there are 15 gauging stations from the overall 103 across Peninsular Malaysia complies with the conditions set for this study. The findings suggest that explicit consideration of rating curve uncertainty in streamflow data is potentially useful in hydrological modeling and flood frequency studies to manage long-term water security.

Ammar Ulwan Mohd Alayudin, Balqis Mohamed Rehan
Hydraulic Properties of Flow Over Different Types of Spillways: A Review

A review of hydraulic properties of flow over the spillway via physical experiment and computational approaches is presented in this paper. The hydrodynamic analysis of flow via the computational fluid dynamics (CFD) approach is vital in solving complex flow problems where the field and experimental assessments are limited. The most selected and efficient turbulence model is the RNG k-ɛ model. Free water surface profile, Froude number, flow regime, velocity, and pressure distribution were identified as the most studied parameters of flow over the spillway structure. These hydraulic characteristics of flow were affected by the geometrical configuration such as the type and arrangement of the spillway. The skimming flow was recognized as the most frequent type of flow in the actual field. The stepped and hybrid types were identified as the most studied concerning functionality in controlling the velocity and dealing with rapidly varied flow types as compared to the ogee-type. Understanding the hydraulic properties of flow is mandatory and important to ensure the serviceability of the spillway structure to safely transfer the water to the downstream section and to minimize the massive impacts of hydraulic jump together with the presence of air–water interface, cavitation, and downstream scour problem. The potential future research work includes an in-depth relationship between the hydraulic characteristic of flow between the efficient spillway structure and the baffle block structure in controlling the hydraulic jump in the stilling basin area.

Nur Azwa Muhamad Bashar, Mohd Remy Rozainy Mohd Arif Zainol, Mohd Sharizal Abdul Aziz, Mohd Hafiz Zawawi, Ahmad Zhafran Ahmad Mazlan
Comparison of Multi-satellite Rainfall Data in Runoff Model

This research was performed to analyze the Global Precipitation Measurement (GPM) 3IMERGHHE and the Tropical Rainfall Measuring Mission (TRMM) 3B42RT in a direct runoff model. The area studied was in Gendol River watershed in Indonesia between February 19th, 2017, and February 26th, 2017. The observed rainfall based on Automatic Rainfall Recorder (ARR) and observed water level based on Automatic Water Level Recorder (AWLR) are used to calibrate the excess rainfall by using the phi index method. The results showed that satellite data could describe rainfall spatially. The TRMM 3B42RT data distinctly propagated to streamflow simulations with a significant magnitude of peak flow. The correction of the satellite rainfall data effectively improved the direct runoff model. In general, the GPM 3IMERGHHE is more feasible compared to TRMM 3B42RT.

Puji Harsanto, Dian Kusumaningrum, Djoko Legono, Adam Pamuji Rahardjo, Rachmad Jayadi
Comparative Study of Radiation-Based Reference Evapotranspiration Models for Tropical Urban Region

Estimation of reference evapotranspiration (ETo) using the FAO Penman–Monteith model become more popular in developing countries. However, it involves complete weather variables data. In order to provide an alternative solution, we evaluated twenty-one radiation-based ETo models against 20-years observed pan evaporation data from Subang meteorological station, Malaysia. To fill the missing data was based on Julian day-based mean imputation. Outlier was tested using Tukey’s detection method prior to estimating the ETo. The percentage of error (% error) in total values, % error in maximum values, % error in minimum values, % error in average values, root mean squared error (RMSE), and the paired t-test of the prediction accuracy were employed to evaluate the performance of the models. The results showed that the Conchrane-Orcutt 2014 model was performed better than the other radiation-based ETo models. The present study recommended the Conchrane-Orcutt 2014 model as the possible alternative ETo model for practical hydrological application according to the smallest difference of RMSE values as compared to the ETpan and due to the less number of required weather variables.

Muhamad Askari, Umar Faruk Lawan, Jazaul Ikhsan, Mohd Remy Rozainy Mohd Arif Zainol, Nor Azazi Zakaria
Methodologies for Estimating the Hydraulic Efficiency of Non-surcharged Clean Grate Inlets, Clogged Grate Inlets and Continuous Transversal Grate Inlets

The urban drainage system of cities is composed of two major and minor subsystems linked by drain inlets to form the dual-drainage system. Therefore, the sewer inlet capacity has a significant influence on the dual-drainage system workability. However, most of the design models and studies focus on the subsurface discharge capacity and neglect the inlet capacity. A reliable drainage system design has to take into consideration the hydraulic efficiency of the lining elements (grate inlets) and the effect of clogging on their efficiency. In this study, the main methodologies for determining the hydraulic efficiency of grate inlets are presented. In a comparative study on the hydraulic efficiency of clean grate inlets, the general hydraulic efficiency formula of Eq. (1) and the formula of Eq. (2) adopted by British Standard and Design Manual for Roads and Bridges and the UPC methodology in Eq. (3) showed similar results with low variance of 2–7%. However, Eq. (3) of the UPC methodology is the most accurate as it considers the majority of the parameters involved in the hydraulic interaction at the grate inlet. Moreover, the UPC methodology of Eq. (3) is proved to be applicable for grate inlets under clogging conditions with high reliability. The approaches presented in this paper can be used in numerical models to provide a reliable accurate simulation of the hydraulic behaviour at the single and continuous grate inlets.

Ali Zaiter, Nuridah Sabtu
Proceedings of AWAM International Conference on Civil Engineering 2022 - Volume 3
Nuridah Sabtu
Copyright Year
Springer Nature Singapore
Electronic ISBN
Print ISBN