International Journal of Integrated Engineering
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Rainfall-Runoff Response of A Suburban Area
Get PDFBatu Pahat experiences flash floods whenever intense rainfall coincides with high tide. Among the factors which cause flash floods are due to Batu Pahat river catchment\u27s flat and low-lying geographical features as well as high-intensity rainfall. The goals of the study are to analyse the frequency of rainfall events for SMK Munshi Sulaiman station and to investigate runoff due to severe rainfall events within the study area. The observed daily rainfall depth record between 2010 and 2021 was obtained from the Department of Irrigation and Drainage (DID) Malaysia. The frequency of rainfall events within the 11-year period is examined using empirical rainfall intensity formulation. Rainfall-runoff of the five most heavy rainfall events in 2021 within the study area are simulated using HEC-HMS. It has been found that most daily rainfall events have a frequency of a 1-year return period. Only three events were found to have a return period of up to 2-year ARI, with a maximum rainfall depth of 110.67 mm. Five heaviest rainfall events in 2021 were obtained from DID\u27s real-time online platform for rainfall-runoff simulations. One of the events, which occurred in June 2021 has a frequency larger than a 100-year return period while other events have return periods ranging from 1-year to 5-year. Simulations produced by HEC-HMS for these events in January, April, May, June, and September 2021 have resulted in peak flow of 6.7 m3/s, 26.8 m3/s, 24.7 m3/s, 39.9 m3/s, and 39.9 m3/s, respectively. Based on frequency analysis, rainfall-runoff simulations, and field observations, it can be concluded that flash floods are highly possible due to high-intensity rainfall as well as lowland topographical features of the study area. Therefore, flood mitigation measures need to be carried out to improve the drainage system for the suburban area
Comparative Analysis between Dynamic Voltage Restorer and PWM-Switched Autotransformer in Voltage Sag Mitigation
Get PDFThis research aims to address the problem of voltage sag, which is a significant power quality issue in power systems. Voltage sag can lead to power transmission and distribution line tripping and cause damage to electrical equipment. Various voltage sag mitigation devices have been developed to reduce the impact of voltage sag. In this study, we analyze the effectiveness of three types of voltage sag mitigation devices under different voltage sag conditions: three-phase fault, multi-phase fault, and energizing transformer inrush current. The three types of mitigations analyzed are Dynamic Voltage Restorer (DVR) with Park\u27s transformation, DVR with Artificial Neural Network (ANN) controller, and PWM-switched autotransformer with Proportional-Integral (PI) controller. The simulation results using MATLAB demonstrate that all voltage sag conditions have been mitigated except for PWM-switched autotransformer during voltage sag caused by energizing transformer inrush current due to limitations of the PI controller scheme. Based on the analysis of input and output voltage waveforms, three-phase voltage magnitude before and after mitigation, and Total Harmonic Distortion (THD) value after mitigation, DVR with ANN controller is identified as the most effective voltage sag mitigation device, followed by DVR with Park\u27s transformation and PWM-switched autotransformer
Evaluating the Weathering Effect on Granite, Limestone and Uncrushed River Stone Aggregates for Road Constructions
Get PDFThe lack of excellent aggregate materials has become a major issue in Sarawak. River stone, abundant in many places of Sarawak, can be used as an alternative aggregate material, minimising the reliance on high-quality aggregates like granite in the production of an affordable and sustainable road pavement. Weathering also deteriorates aggregate materials. This project aims to investigate the durability of granite, limestone, and uncrushed river stone aggregates with regards to weathering effects. The aggregates are subjected to two conditions, i.e., normal condition (without wetting and drying cycles) and wet-dry condition (with wetting and drying cycles). The physical properties of aggregates are determined by the Flakiness Index, Elongation Index, and Specific Gravity. Weathering effects on aggregates are determined using laboratory tests such as Aggregate Impact Value (AIV), Aggregate Crushing Value (ACV), and Los Angeles Abrasion (LAA). Weathering cycles have been found to have a minor impact on aggregates in the short term. Overall, the test results indicate that wetting and drying circumstances have a negligible effect on aggregates over a short period of time. The materials\u27 physical attributes all meet JKR requirements. The Aggregate Impact Value (AIV), Aggregate Crushing Value (ACV), and Los Angeles Abrasion (LAA) values are nearly constant across the wet-dry state for all aggregate kinds. Despite the wet-dry situation, the AIV, ACV, and LAA tests demonstrate that specific aggregate materials retain their durability when compared to other aggregate materials. As a result, granite is the most durable aggregate in terms of AIV and LAA when compared to limestone and uncrushed river stone, while uncrushed river stone is more durable in terms of ACV when compared to granite and limestone
Living Walls in The City: Community Values and Expectations
Get PDFThere is an increasing interest in living walls in the urban environment, particularly when linked into green infrastructure for urban heat island mitigation. However, the social acceptance of such systems in Australia is largely untested. To address this knowledge gap, a survey of nineteen local government authorities and twenty living wall owners and managers was conducted. The survey participants included commercial and residential buildings. The survey was used to study living wall owners’ motivations and expectations of living walls as well as the social values attached to the installed infrastructure. This study related the experiences of living wall owners to the current technical knowledge of living walls and contextualised the benefits and costs of living walls for Australian homes and buildings within the public attitudes and motivations for installing such infrastructure. The survey found that social acceptance and the aesthetic values placed on living walls and greenery more broadly represented a substantial advantage for living walls
Compressive Strength, Temperature Performance and Shrinkage of Concrete Containing Metakaolin
Get PDFThe influence of metakaolin (MK) on concrete was investigated as a partial replacement of cement, which is liable for high content of CO2 emission during the manufacturing process. The study aimed to assess the compressive strength, temperature performance and drying shrinkage of MK blended concrete. Different ratios of MK (5%, 10%, and 15%) as cement replacement, and two ratios of superplasticizer (SP), 1.5%, and 2% as cement weight were utilized in this study. The results indicated that using MK increased the compressive strength at 28¬ day. The improvement of strength is ascribed to the pozzolanic reaction and the packing effect of fine MK particles. MK blended concrete experienced a decrease in the temperature rise of heat of hydration (HOH) and low drying shrinkage when compared to the control concrete. The SP ratio does not have significant effect on the temperature of the concrete mixtures: however, using 1.5% SP slightly reduces the drying shrinkage of MK blended concrete compared to 2% SP. In conclusion, Incorporation of MK as partial cement substitute enhances the concrete strength, thus various types of concrete can be produced. Low temperature and drying shrinkage of MK blended concrete help in reducing thermal crack after casting process
Assessment of Wave Attenuation Performance of the Tanjung Piai Breakwater Using Spectral Wave Analysis
Get PDFTanjung Piai is one of Malaysian heritage sites situated at the southernmost tip of the Asian continent. Tanjung Piai provides a conducive coastal habitat for many mangrove species, including the rare species of Bruguiera hainesii and Bruguiera sexangula. Coastal erosion resulting in shoreline retreat that was detected dating back to the 1930s. Due to uncontrolled coastal development ij the vicinity of Tanjung Piai, the erosion rate at the mangrove site had accelerated since the recent decades. This led to significant land mass loss that threatens the eco-system. Various measures have been undertaken to mitigate the erosion problems. Some measures were adopted to permanently harden the shoreline preventing sea water from reaching the mangroves. However, this resulted in mangroves gradually dying along the coast.. A series of offshore breakwaters were subsequently planned to reduce wave energy, mitigate the erosion and protect the existing mangroves growing along the wave-exposed coastline. This study aims to assess the impact of offshore waves, squalls and wind-generated waves to the Tanjung Piai coastline (with and without the breakwaters) using a two-dimensional numerical model. A survey of the site and details of the breakwaters’ design were incorporated in the modelling. The numerical results show that the breakwaters are able to reduce offshore wave heights up to 66%. The breakwaters can attenuate offshore waves more effectively compared to squalls and wind-generated waves. The breakwaters were completed in 2019. They were proven to be able to provide protection to the mangroves along the coast of Tanjung Pia
Factor and Influential Variables Affecting Maintenance Cost of Urban Rail Rolling Stock
Get PDFIt is a known fact that the cost of maintaining rolling stock is huge due to its higher acquisition cost and maintenance activity. This research paper aims to analyse, evaluate, and rank the influential variables contributing towards rolling stock maintenance cost. A quantitative approach was adopted for data collection and factual data from Malaysia\u27s rolling stock practitioners was collected using a survey. The research first identified the influential variables associated with rolling stock maintenance cost through literature review. A questionnaire survey was conducted among five Trains Operating Companies in Malaysia. These were performed using importance index to accomplish ranking analysis. The research has discovered five groups of predictor factors that affect rolling stock maintenance cost and 14 influential variables to execute the maintenance activity. This study has highlighted the possibility of future major studies in cost structure implied by group of predictors to predictive cost model for rolling stock maintenance
Different Approaches of Multiple Linear Regression (MLR) Model in Predicting Ozone (O3) Concentration in Industrial Area
Get PDFMeteorological conditions and other gaseous pollutants generally impacted the development of ozone (O3) in the atmosphere. The purpose of this study was to create the best O3 model for forecasting O3 concentrations in the industrial area and to determine the variables that affect O3 concentrations. Five-year data of meteorological and gaseous pollutants were used to analyze and develop the prediction model. Based on three distinct techniques, three separate multiple linear regression (MLR) prediction models of O3 concentration were developed. MLR3 had the highest correlation coefficient of 0.792 during development as compared to models MLR1 and MLR2. MLR2 was deemed the best O3 prediction model, however, since it had the lowest error values of root mean square error (3.976) and mean absolute error (3.548) when compared to other models. The establishment of an O3 prediction model can offer local governments with early information that could help them reduce and manage air pollution emissions
Physical Characterization of Modified Asphalt Binder with Differing Fly Ash Geopolymer Contents
Get PDFNowadays, the use of waste material product has gained popularity in the production of asphalt mixes and becomes a cost-effective method of pavement construction that can decrease the consumption of natural resources and to reduce environmental pollution. This research aimed to investigate the possibility of using waste and by-product material namely fly ash geopolymer additive to influence the physical properties of asphalt binder. An experimental matrix of laboratory testing was conducted to study the properties of the 60/70 and 80/100 asphalt binder with modified binder containing 3%, 5%, 7%, 9% and 11% of fly ash geopolymer additive. The physical properties of the binders were determined using the penetration, softening, penetration index, ductility, and rotational viscosity respectively. The results indicated that, the fly ash geopolymer modified binder had improved the physical properties over base binder. The thermal susceptibility also improved by referring to the Penetration Index value. Overall research conclusions are that geopolymer application resulted in a potential enhancement of some of the properties of the asphalt binder and increase the performance of asphalt binder in the pavement application
Mechanical Properties of Laminated Veneer Lumber (LVL) Fabricated from Three Malaysian Hardwood Species
Get PDFThe application of laminated veneer lumber (LVL) has long been limited to non-structural elements in Malaysia. The LVL is commonly fabricated with veneer from low to medium density (290 to 630 kg/m3) softwood or temperate hardwood. The data on the properties of LVL made from medium to high density (567 to 687 kg/m3) tropical hardwood species is very limited. Therefore, this study investigated the mechanical and bonding properties of LVL fabricated from Malaysian hardwood species namely Kasai (Pometia spp.), Mengkulang (Heritiera spp.) and Kedondong (Canarium spp.). Different variables were studied: i) wood species; ii) loading surface (flatwise or edgewise), iii) grain direction (parallel and perpendicular), iv) treatment condition. The bending and compression test was carried out in accordance with EN 408:2012, while the block shear test was conducted based on EN14374:2004 and EN 314-1:2004. The results shows that the grain direction has the most significant effect (P ≤ 0.01) on the bending, compressive and bonding properties of the samples tested. The treatment conditions for block shear test also displayed significant effect on its shear strength. The samples loaded parallelly displayed bending values 320-450% higher than the samples loaded at perpendicularly. The compressive strength and compressive modulus are 323-365% and 523-2530% respectively when loaded parallelly. LVL performed better mechanically when loaded parallelly and when subjected to less extreme treatment conditions