Research Papers - Department of Civil Engineering

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End date: 2019Subject: search.filters.subject.Sri Lanka

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Now showing 1 - 8 of 8
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    PublicationEmbargo
    Pavement maintenance management system for low volume roads in Sri Lanka
    (IEEE, 2019-07-03) Perera, M. Y. I; Pasindu, H. R; Sandamal, R. M. K
    In Sri Lanka there are about 150,000 km of roads and among those about 75% are considered as rural low volume roads [1]. These roads are essential in community development, transport of people, goods and services in the rural areas. Most of these low volume roads would be actively contributing to our country's economy and wellbeing by distributing the produces from rural areas to urban areas. Limited funding, subjective and ad-hoc maintenance decision making has resulted in suboptimal maintenance level for these road networks. There is no proper maintenance system available in Sri Lanka as in the foreign countries. Lack of technical expertise and shortage of human resources, equipment and funds to carryout detailed data collection and analysis makes use of existing Pavement Management Systems difficult for local road agencies. The study will be focused on developing an asset management system to manage rural and provincial road networks in Sri Lanka.
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    PublicationOpen Access
    Risk Factors of Motorcycle Crashes in Sri Lanka
    (University of Moratuwa, 2016) Amarasingha, N
    The use of motorcycles has become a passion or even a way of life in many South Asian countries including Sri Lanka, for commuting to work or transporting goods, as they are easy to use and to cover short distances. In these countries, ownership and use of motorcycles and other two-wheelers are generally relatively high. Compared to drivers of other vehicles, motorcyclists are vulnerable road users as they often share the traffic space with fast-moving vehicles, they are less visible, and also they lack protection in the case of a crash. All Sri Lankan regulations for motor vehicles are applicable to motorcycles. The owners are required to register their vehicles and also obtain driving licences to operate motorcycles. They also are required to obtain annual revenue licenses. Motorcycles are popular among middle income and low income people in Sri Lanka and mainly used to commute to work and also used to transport goods, as well as for recreational purposes. The most common vehicles on Sri Lankan roads are motorcycles and the number of motorcycles is more than three times the number of the second most popular vehicle, namely the three-wheeler. The percentage of increase of registered motorcycles in Sri Lanka from year 2003 to 2012, was 152% [1]. As the number of motorcycles increase, so does the probability of their being involved in motor vehicle crashes.
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    PublicationOpen Access
    Characteristics of Railway-Roadway Level Crossings at Coastal Railway Line in Sri Lanka
    (KDU IRC 2017, 2017) Amarasingha, N; Gunathilaka, O. H. D. C; Ragulan, K; Aravinda, M. P. N; Fernando, W. S. H. R
    Rail transportation is a safe, efficient, continuously operating sustainable transportation mode, in all-weather conditions, and light conditions. Along with these advantages, the role of rail transport has become increasingly important. Therefore, it is important to investigate the characteristics of the railway-roadway level crossings in Sri Lanka. Railway-roadway level crossings at coastal railway line from Aluthgama to Ambalangoda were visited to collect the roadway, railway, traffic, environmental, and crash data. Out of 51 crossings that observed in this study, about 94.1% of railway-roadway level crossings were facilitated with active safety measures. About 7.0% of railway-roadway level crossings were without gates and among them 33.3% of crossings were facilitated with passive safety measures and other crossings were under unsafe conditions. Several problems related to railway-roadway level crossing were identified. The collected data could be utilized to develop various statistical models for identifying relationships between the number of crashes and level crossing characteristics. It could be used to identify potential highcrash prone railway-roadway crossings and key factors which increase the number of crashes.
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    PublicationOpen Access
    Development of a Formula to Quantity Emlsslons Generated from Dlesel Vehicles in Sri Lanka
    (ACEPS-2017, 2017) Konara, K. M. T. N; Samarasekara, G. N; Chaminda, G. G. T; Dissanayaka, A. W; Perera, S. V. T
    Using the combination of optical properties of diesel exhaust and Beer Lambart law, particulate concentration was derved. Major component of the particulate matter of diesel exhaust was elė carbon which was derived from the optical properties of diesel exhaust. Characteriza emission composition was done through literature. According to the Spaciate 4.0 databa state environmental agency, characterization of diesel emission was finalized. Spaciate 4 the diesel exhaust is a primary combination of Organic carbon (31.80%), Elemental ca Sulphate (0, 67%), Nitrate (0.19%) and others including metallic components and etc.(6 that, a balanced chemical equation was formed for the incomplete combustion of the di air. Calculation of CO2, CO and PM was derived based on the stoichiometric ratio of the bäjä chemical equation.
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    PublicationOpen Access
    Impact of urbanization on earth resources in suburbs of Colombo, Sri Lanka
    (NSF: Colombo, 2019) Rathnayake, U. S
    Climate change is believed to be a critical issue and there is enough evidence to identify the impact of climate change. Sri Lanka is expected to be one of the most affected countries from adverse impact of climate change. Various climatic models propose a rise of rainfall intensity to south Asian region while the number of rainy days are to be reduced. Therefore, the necessity is raised to find the clear trends in climatic factors in the region. However, a very few research work was carried out to see the climatic changes over the last few decades in Sri Lanka. Temporal variation of precipitation (rainfall) can be a good indicator to identify the trends in climate. In addition, these rainfall variations are used in many engineering aspects, including design of massive civil engineering structures like dams, design of water supply networks, etc. Furthermore, the rainfall variations are not only important in engineering aspects but also heavily in agriculture. Therefore, this research work targets to find the temporal variations of rainfall n Sri Lanka and then, to project the results to the available water resources.
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    PublicationOpen Access
    Hydrological assessment of flow in Uma Oya, Sri Lanka
    (Faculty of Engineering, Sri Lanka Institute of Information Technology, 2015-01-29) Rathnayake, U. S
    A current meter is usually used in river flow measurements. However, if someone is interested in obtaining the temporal variation of a particular river, it may not be the easiest method in the world to use a current meter (i.e. daily) to measure the flow rate. In such events, the stage measurements can be taken and then, they can be converted to the flow rates (USGS, 2014). One can use the stage-discharge relationship to find the corresponding flow rate (Mortuza et al., 2011; Raj and Azeez, 2009; Gupta and Chakrapani, 2005). However, this method still requires some flow measurements to produce the stage-discharge relationship. Therefore, a current meter should be there to measure the velocities and then, to calculate the flow rates. In case of absence of a current meter, one has to think another way of obtaining the flow hydrograph. This paper presents a simple approach in obtaining the flow hydrograph for a river in Sri Lanka: Uma Oya. Uma Oya catchment is being modeled and this study shows some preliminary results. The detailed flow hydrograph for Uma Oya for a longer period is being developed for the frequency analysis. The developed flow hydrograph is being used to model the Uma Oya catchment in Sri Lanka
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    PublicationOpen Access
    Urbanization and initial groundwater quality investigation in Malabe, Sri Lanka
    (https://www.tci-thaijo.org/index.php/easr/article/view/91589, 2018-06) Rajapakshe, A; Rathnayake, U. S
    Malabe, an eastern suburb of the capitalcity of Colombo, is one of the most rapidly urbanized and industrialized areasin Sri Lanka. Groundwater is avaluable resource inMalabe and itis being polluted. Malabe is located in a wet climatic zone with alateritic aquifer thatnormally contains water with avery low pH thatcan cause quality problems. Our objective was to investigate and analyzethe Malabe groundwater quality to understand the characteristics of significant parameters and their correlation so that policy planning can be correctly done. Groundwater samples from 16 water wells were collected and evaluated for eightphysicochemical parameters,i.e.,pH, turbidity, electrical conductivity (EC), color, nitrate (NO3), nitrite (NO2), sulfate (SO4), and phosphate (PO4). Two biological parameters were also determined for four wells. The essence of this finding is that the groundwater is very acidic, has a very low EC, but high coliform counts. Multivariable statistics of the data were performed usingPearson’scorrelation and principal components analysis (PCA) using the Princom package intheR statistical package. The first four principal components (PCs) explained 79.8 % of the total observed variance inthe data. The most significant parametersfrom the first principalcomponent, PC1, were the positive correlationsof turbidity andPO4, and negative correlationsof EC andNO3. Asignificant positive loading of pH with a negative loading of SO4was illustrated in PC2. These findings were similar to the correlation results. We concludesthat the high acidity of the groundwater is primarily caused by industrial waste. The groundwater pollution of the Malabe area was not cause by inorganic fertilizer but by anthropogenic waste runoff. Our finding is crucial for groundwater quality management inthe study area.
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    PublicationOpen Access
    Rainfall trend analysis in Uma Oya basin, Sri Lanka and future water scarcity problems in perspective of climate variability
    (https://www.hindawi.com/journals/amete/, 2019-04) Khaniya, B; Jayanayaka, I; Jayasanka, P; Rathnayake, P
    The effect of climate variability on the rainfall pattern is canvassed on the Uma Oya river basin, Sri Lanka, consisting of 5 rainfall gauging stations. The Uma Oya basin (720 km2) is given utmost precedence due to environmental concerns seen in the ongoing Uma Oya multipurpose development project (529 million USD worth) which is expected to divert water to the southeast dry zone of the country while adding 231 GWh/year electricity to the national grid. The rainfall data for a period of 26 years (1992–2017) were analysed using Mann–Kendall’s test and Sen’s slope estimator test to identify the rainfall trends. Both of these trend analysis test results depict only one negative trend for Hilpankandura Estate for the month of June; however, the seasonal trend analysis and annual trend analysis do not support this observation. Nevertheless, Mann–Kendall’s test showed potential positive trends for the 3 rainfall gauging stations Kirklees Estate, Ledgerwatte Estate, and Welimada Group only in the 1st intermediate period (March-April), and this is well supported by the monthly trend analysis. Other than these trends, the results do not show any significant negative trends in the Uma Oya catchment. Therefore, the results vividly explain that there is no threat of water scarcity to the catchment area being resistant to changing global climate for the past 26 years.