2014-9th

Permanent URI for this collectionhttp://192.248.9.226/handle/123/13514

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Now showing 1 - 20 of 41

item: Conference-Abstract
Proceedings of the Civil Engineering Research For Industry Symposium 2012 [Pre Text]
(Department of Civil Engineering, 2014)
item: Conference-Full-text
Recognizing temporal variability of lump watershed behaviour and evaluating averaged performance of a hydrologic model
(Department of Civil Engineering, University of Moratuwa, Sri Lanka., 2012-12) Wijesinghe, WMD; Wijesekera, NTS; Nawagamuwa, U; de Silva, LIN
Majority of watersheds associated with civil engineering infrastructure projects are ungauged and most commonly used method to determine streamflow in ungauged basins is mathematical modelling with the use of Synthetic Unit Hydrograph (SUH) technique. Mathematical models require watershed characteristics to be spatially and temporally averaged. The SUH is an event based model which estimates direct runoff. Hence model calibration and verification requi: : event based evaluations with a baseflow separation effort or a method incorporating a baseflow model to combine with the SUH model and generate total runoff. In this study, a rainfall runoff model developed using SUH and a linear baseflow concept while selecting the watershed of Attanagalu Oya at Karasnagala as the study area. Other than the SUH parameters to be identified, the conceptual model used for this work consisted of 5 model parameters to be optimised. The main objective of this research was to identify the issues during calibration and verification of this five parameter model. Model calibration was carried out for 30 datasets, selecting the Mean Ration of Absolute Error (MRAE) as the objective function. Optimum model parameters for each event were determined and the most probable range of values for each parameter was computed. Using 30 datasets, model was verification was carried out by assuming that the average of each range would lead to a representative watershed model. A successful calibration produced a good match of observed and calculated streamflows with a MRAE of 0.34. Parameter optimisation revealed the inability to obtain an average initial moisture level for the entire watershed while catering both wet and dry conditions. The runoff coefficients and rainfall thresholds also indicated the need of further investigations. Event based modelling approach in this work provides an insight to the watershed behaviour and to the appropriateness of model parameters, however in order to identify the spatially and temporally averaged parameters it is necessary to carryout optimisations using a lengthy data series together with an appropriate model.
item: Conference-Full-text
Guidelines for the implementation of bicycle lanes on Sri Lankan highways
Salawavidana, SAST; Liyanaarchchi, LATU; Senarathna, RMSK; Mampearachchi, WK; Bandara, JMSJ
Bicycle lanes have become an integral part of the highway networks of many countries including Sri Lanka. They are encouraged as a pollution free, economic and healthy mode of transport throughout the world. So it is high time that a proper guideline for the same is introduced taking into account the local conditions of this country. Bicycle lanes are so far introduced to the road projects of Sri Lanka on ad hoc basis without consideration of the proper guidelines such as continuation of bicycle lanes on the road network, intersection treatment, avoidance of abrupt termination etc. Sri Lanka being a developing country with more or less a feudal framework of thinking, there is a social stigma towards the bicycling as a poor man’s vehicle. In such a context, how should a design engineer in cooperate this green technology into our local highway projects so the common man can be immensely benefitted and our cities will be left with some fresh air to breath in the coming days of the future? This research was aimed at addressing these issues and finally coming up with a proper guideline to implement bicycle lanes in the future road projects carried out by Road Development Authority.
item: Conference-Full-text
Guidelines for road diet conversions
Stamatiadis, Nikiforos; Kirk, Adam
Road diets, which convert four-lane highways to three-lane cross sections, are an innovative solution to address mobility and safety concerns under budgetary constraints. These improvements can assist in the development of multimodal corridors with minimal impact on automobile mobility, while retaining the original right of way. Past research has focused on evaluating road diet safety, but minimal guidance exists on determining when such conversions are appropriate from an operational perspective. The proposed guidelines focused on evaluating and comparing the operation of three- and four-lane roads at signalized intersections to provide basic guidance as to when the road diet conversion is appropriate. One of the important findings of this research is the expansion of the usable range for road diets. Prior experience has limited road diet application to roadways with ADTs less than 17,000 vehicles per day. This research identifies the importance of side street volumes and supports the utilization of road diets on roadways with volumes up to 23,000 vehicles per day. This paper provides comprehensive guidance for road diet evaluation including operational performance, correctable safety problems and identifies a list of evaluation elements that should be examined when in-depth analysis of alternatives is required.
item: Conference-Full-text
Applicability of ridesharing using paratransits: a case study from a university community in Sri Lanka
Jayasinghe, RMTTB; Sivakumar, T
Recent increase in number of singly hired para-transit usage in Sri Lanka favors ride shared paratransit modes. Applicability of ridesharing is studied in a selected corridor by examining the attitude of the passengers and drivers. The undergraduates of University of Moratuwa (passengers) were selected as the population and one of the access road (between Katubedda junction and university) was selected as the study area with Three-Wheel (3W) mode as common para-transit mode in Sri Lanka. Structured questionnaire was used to gather users (3W passengers) preference and drivers willingness along with road side survey on 3W movements to study the existing situation in the study area. The study focused on effects of ridesharing on three aspects while identifying barriers for ridesharing implementation; (1) demand for 3W, (2) monetary benefit for 3W operators and (3) Environment. It is found that implementing ridesharing with pool of three passengers and with fare of LKR (Sri Lankan currency- Rupees) 20 (less than ⅓ of the current fare, LKR 70) per head; (1) increases 3W ridership by 42%, (2) increases daily profit of the drivers by 13.3% compared to the existing (average vehicle occupancy=1.4) operating cost and (3) Reduces emission cost per user by 50% per passenger. Barriers to ridesharing from users are reluctant to share rides with unknown passengers (stranger-danger) and also with opposite gender while that of from operators is the fear from peer operators like other 3W drivers and bus operators. Implementing ridesharing is certainly a win-win case for both users and operators.
item: Conference-Full-text
Optimization of multi-objective outbound logistics operation
Dharmapriya, USS; Kumarage, Amal S
Distribution, one of major outbound logistics functions draws attention due to high cost incurred. This study investigates the planning of a real time distribution operation achieving three objectives simultaneously. Route optimization, truck utilization and equal delivery make-span have been accompanied in order to address the problem giving financial benefits to company and satisfying the stake-holders. It is a real challenge to fulfill these three objectives concurrently; however, this research provides promising solution for the problem combining both exact and heuristics techniques. Heuristics techniques exploits to cluster the customers ensuring equal delivery make-span and Dijikstra algorithm has been modified to generate optimal route in terms of distance and delivery quantity. Algorithm was developed in C++. Results reveal that proposed route planning reduces the cost by 11.5 % included with 50% reduction of fleet size and 37% saving of travel distance.
item: Conference-Full-text
Stabilization of expansive clay soil using buton rock asphalt the other utilization of buton rock asphalt
Rusbintardjo, Gatot
Subgrade is the lowest layer of the pavement that must eventually support all the loads that come onto the pavement structure. Therefore, it is essential to make sure that the layer is stable and has sufficient shearing strength to withstand the traffic induced stresses without excessive deformation. If the subgrade soil is poor, sufficient shearing strength, then it must be stabilized to improve its properties. In this paper Buton Rock Asphalt (BRA) was studied to stabilize the expansive clay subgrade soil of Semarang-Purwodadi road in North-East Central Java Province of Indonesia. Amount of 2%, 4%, 6%, and 8% of BRA by weight of soil were added. As comparison or control, natural sand in amount of 5 to 25% in increments of 5% by weight of soil was also added. Laboratory works show that BRA can improve bearing capacity of soil far higher than the natural sand resulted. By adding 8% by weight of soil, BRA can improve bearing capacity of those of expansive clay soil, measure by using CBR, from the value of CBR 1.6% to 5.97% or increase 373%, while 20% of sand only increasing the CBR of soil become 3.90% or increase 244%. Increasing of CBR by adding BRA is in linear line with the line equiation y = 51.54x + 2.126. This mean if the percentage of BRA also 20% the CBR value of BRAstabilized soil is 12.43% and suitable as well as very good for subgrade material.
item: Conference-Full-text
Failure analysis of a semi structural pavement using a mechanistic tool – case study for a provincial road
Jayarathna, KARN; Mampearachchi, WK
Pavement design is a vital part in new road construction and in rehabilitation projects. Conventional flexible pavements are layered systems with high stress intensity on top and low intensity at the bottom. AASHTO method is widely used by most of the road agencies to design pavements while the Transport Research Laboratory (U.K) Road Note 31 (TRL RN-31) specifies for the tropical countries. Both these design guidelines are based on empirical formula or experimental studies conducted in extreme weather condition. Road Note 31 specifies the layer thicknesses of specific materials. It does not specify a method to adopt the materials that does not fit the specifications, which is the commonly encountered problem due to the varying site condition and availability of materials. Empirical design methods do not have any provision for analysing road failures and propose most suitable rehabilitation method. Therefore this research focused on evaluating the suitability of a mechanistic empirical pavement design tool to investigate a pavement failure. In this study, failure of a Sri Lankan rural road which is failed immediately after completing the construction was selected for the analysis. This road was designed according to the Overseas Road Note 31(ORN 31) as a Double Bitumen Surface Treatment (DBST) road and it has shown longitudinal cracking on the surface followed by the depression and the settlement, approximately after six months from the completion. Heavy axle load applied on the pavement due to transporting of construction materials to a new project has increased the propagation of cracks and potholes. Soil samples collected from the critically damaged locations were tested and the results showed that the inadequate strength of the pavement structure as the cause to the failure. Failure investigations were done using a mechanistic tool called CIRCLY and reliable reclamation method was proposed.
item: Conference-Full-text
Prediction of unconfined compressive strength of old asphalt concrete using multiple regression
Jaritngam, Saravut; Somchainuek, Opas; Chantruthai, Piti; Ratanavaraha, Vatanavongs; Taneerananon, Pichai
The recycle of old asphaltic concrete material (OAC) with cement additive is a relatively new pavement improvement method in road geotechnical engineering in Thailand. This paper describes the test results of recycled old asphaltic concrete mixed with various amounts of cement additive (OACC) at different durations of curing time, compared to the OAC without any additive. The test results show that the strength of OACC increases with the increase in amount of cement additive. A multiple regression model was developed for predicting the unconfined compressive strength (UCS) of the recycled old asphaltic concrete with cement additive (OACC) using cement content and curing time as input. The performance evaluations showed that predictions by the multiple regression model are very satisfactory in estimating the UCS.
item: Conference-Full-text
A study of road network development prioritization at Lembata district - east nusa tenggara province, Indonesia
Djakfar, Ludfi; Anwar, M Ruslin; Ignasius A, Gerardus
The objective of the study was to prepare a recommendation on how to set up a road network construction programming in Lembata District, Indonesia given such constraints as budget, types of construction, and so on. There were eight road segments across Lembata District included in the road network under consideration. To achieve the objective, the Analytic Hierarchy Process (AHP) method was applied. The process was initiated by brainstorming factors that may affect the selection and prioritization, called in the AHP analysis criteria. The factors were then evaluated using the Cut Off method to select the most suitable ones. From the analysis it was found that factors strongly influence in the selection were road condition, type of road surface, accessibility, mobility, population density, land use disparity, poverty alleviation program, and construction cost. Using the above criteria, an AHP analysis was then conducted to set up a prioritization recommendation for the road construction sequences. It was found that the construction cost was the most important factor to be considered, followed by land use disparity and road condition.
item: Conference-Full-text
New methodology for developing driving cycle(s) for Sri Lanka; case study, Colombo, Sri lanka
Galgamuwa, Uditha; Perera, Loshaka; Bandara, Saman
Even though driving cycles have been adopted around the world in different type of applications, the data needed for each steps is costly and time consuming. Majority of the Developing countries do not have systematic data bases for traffic related information such as origin-destinations, vehicle kilometers, average annual daily traffic etc. for majority of road links. Meager amount of available data is not sufficient to develop a driving cycle. Even though the data is collected, significant effort has to be made to construct a driving cycle that closely matches to the population data set. This paper gives simplified methodology for developing driving cycles using different approaches for route selection, data collection and cycle construction. For the route selection the available methods have been combined together and modified to suit for developing countries where no details traffic flow information will be available. Also a method was adopted for data collection by dividing selected routes in to links and grouped them according to daily traffic to optimize the cost for data collection. Road links were divided using physical junctions on the road and routes were selected using traffic generators and attracters combined with Origin Destination data. Also methodology was developed for synthesize data population using collected data from road links. Another issue for cycle construction is to construct a cycle which is close to population parameters. Using existing methods many cycles have to be constructed until the acceptable cycles is generated. New methodology has been adopted to develop driving cycle to match the population parameters and then to select data for driving cycle using Markov chain. As a case study Colombo, Sri Lanka has selected to apply the new approach of driving cycle construction for developing countries.
item: Conference-Full-text
Prioritizing transport infrastructure projects at early stages of projects
Gamalath, Isuru; Perera, Loshaka; Bandara, Saman
Investment on transport infrastructure is a significant component in a country’s budget as it is identified as a key factor to facilitate the country’s development. At the same time demand for transportation is positively correlated with the development. With this increasing demand for transport infrastructure and limited funding available, it is necessary to prioritise appropriate projects. Current appraisal practices at the early stages of projects fail to identify some important criterions and therefore, may ultimately end up not selecting the most appropriate project(s) which addresses contemporary concerns. Therefore the objective of this study is to identify a cost effective method and factors that should be considered in evaluating alternatives at the early stages of transport infrastructure projects. Both academic and grey literature was reviewed to identify current practises; methodologies and factors concerned in the recent past. Most of the time feasibility reports used descriptive format and often gave vague conclusions. Therefore the final selection of alternative(s) is implicit. A performance matrix was developed in this study based on multi criteria analysis linear additive model. This method was primarily selected as it is easy to use in practise. In addition to the traditional criterions, this matrix contains new criterions that should be looked into with the current interests. A case study for Kandy expressway alternative selection based on this developed performance matrix is presented in this paper. In addition to the new matrix, a modified scoring system was used in the analysis to minimise the variations, as scores are given by different experts. Further, analysis was compared with the view of different experts and results of sensitivity analysis to address the possible arguments on weight given to each criterion.
item: Conference-Full-text
Audiometric assessment of urban road traffic noise affected persons: a case study of Surat, India
Tandel, BN; Macwan, JEM
Among all of the sources responsible for noise pollution, traffic related sources are of great environmental concern and increasing level of discomfort in urban areas with increasing traffic concentration. It will be a larger and serious problem in the future, if effective precautions are not taken addressed and attended to. Hence, a study was undertaken to measure the levels of road traffic noise at major intersections of Surat city, located in Western India and assess the hearing impairment among the exposed group of population. Manual noise measurements and vehicle counts were performed at three of the busiest traffic intersections in the city for a period of 12 hours. Audiometric screening was done on 46 urban road traffic noise affected persons, working or staying at these intersections to determine the occurrence of hearing impairment. At all the three intersections, Leq measured was well above the permissible levels of 65 dBA for daytime. The Lmax recorded for three intersections were 84.6 dBA (07:36 PM), 87.3 dBA (06:32 PM) and 85.6 dBA (11:41 AM). Audiometric screening showed that only 10 persons (22%) had normal hearing. slight, moderate and severe hearing impairment was recorded among 13 (28%), 18 (39%) and 5 (11%) persons respectively. Of the total 46 participants, none had profound impairment (deafness, hearing loss > 81 dB). Of the remaining 36 having hearing impairment, 27 had bilateral impairment.
item: Conference-Full-text
Numerical analysis of horn effect reduction on porous pavement
Zhang, Lei; Ong, Ghim Ping; Fwa, Tien Fang
Porous pavement is often seen as an effective engineering solution to reduce traffic noise. It works by reducing the horn effect of tire/road noise generation using its acoustic absorbing ability. Sound energy dissipates when it propagates through the porous surface layer due to the viscous and thermal effects resulting from the compression and expansion of air within the micro-structure of pore network. This sound absorption becomes more significant when it comes to horn effect because the multireflection process makes the absorption occur multiple times in sound propagation. Despite the significance of horn effect reduction on porous pavement, research studies on this topic are still limited to date. This paper attempts to investigate the horn effect reduction in a numerical perspective. A brief description of the acoustic characteristics of porous pavement is presented. Representative phenomenological and microstructural models which are capable to derive the acoustic impedance of porous pavement from its volumetric and composition characteristics are introduced. A numerical horn effect measurement model using boundary element method is then developed and validated against experimental results. This model is next used to analyze horn effect reduction on porous pavement. The influence of source position, the directivity of horn effect reduction, as well as the influence of the thickness and porosity of porous layer are examined. The simulation results demonstrate the feasibility of BEM model in the analysis of noise propagation on porous pavement and can provide some in-depth understanding of the horn effect on porous pavement.
item: Conference-Full-text
Modeling nonlinear suspension system for improved braking distance estimation
Yang, Jia Sheng; Fwa, Tien Fang; Ong, Ghim Ping
Braking distance of a vehicle is an important safety consideration in highway geometric design. Braking distances have been commonly estimated based on vehicle wheel loads and assumed tirepavement friction. The use of classic vehicle dynamics simulation model, which simplifies tire stiffness as linear elastic function, is a main approach to estimate tire-pavement friction and predict braking distances. The interaction of nonlinear vehicle dynamics with pavement surface roughness has not been considered in analyzing its impact on vehicle braking distance. The impact of pavement roughness induced vehicle vibration on braking distance is the topic of interest in this paper. A nonlinear vehicle dynamics simulation model is proposed where tire stiffness is considered as a nonlinear elastic function in the analysis of vehicle dynamics. The model is implemented in MATLAB 11.0. A hypothetical example is given to illustrate the possible difference between models with linear and nonlinear tire stiffness in calculating braking distance on a wet pavement. Although the model presented is rather simplified considering only nonlinear tire stiffness, and a more elaborate simulation model is required to examine in detail the actual impact of considering nonlinear vehicle dynamics, the example does show that further study is necessary to examine the need for vehicle dynamics simulation in order to reliably predict vehicle braking distances on highways, taking into account the effect of pavement roughness.
item: Conference-Full-text
Accident prediction model for highw ays with rest area by using poisson and binomial regression model
Tipakornkiat, Chalat
Currently, rest area positively impacts on road users in terms of business points and information providers; however, the important task of rest area is reducing the number of road accident cause of fatigue. In the past, truck drivers in Thailand usually parked their vehicles on roadside or shoulder, which these harmful areas could generate road accidents when parked vehicles move out from the road shoulder to the travelled way. In Thailand, road accident situation is top 10 of the world. Research objectives consist of the determination of influencing factors that affect the road accident within upstream and downstream 16 km of rest areas in Thailand and built the accident prediction models. It was found out that main variables such as serviceability of rest areas and the number of the truck users in rest areas are significantly impacted into the accident prediction model. In summary, rest area could help to reduce the number of road accidents.
item: Conference-Full-text
Initial development of Indonesian motorcycle rider behaviour
Putranto, Leksmono Suryo; Anjaya, Ivan Skyler
The use of motorcycle in Jakarta increased rapidly in the last ten years. This is due to lack of sufficient public transport services. The public tried to overcome the congestion problem individually by using motorcycle. Among the daily users of motorcycles were university students. This paper dicusses the development of motorcyclist behaviour questionnaire in Indonesian context. Interviews were conducted to 100 male motorcyclists and 50 female motorcyclists. All respondents were Tarumanagara University students in Jakarta. The questionnaire consists of 31 statements reflecting motorcylist behaviour. The statements were the result of of focus group discussion among researchcers in this topic. Respondents were asked to rate whether they strongly agree (1), agree (2), disagree (3) or strongly disagree (4) to each statement. The collected data were analyzed using exploratory factor analysis (EFA).
item: Conference-Full-text
Driving behavior: traffic risk perception and intentions to commit driving violations in Iran
Tabibi, Zahra; Chahnoeei, Hoda Hashemi
Road traffic injuries are the leading cause of death and injuries. Violation of traffic rules is one of the reasons for accident involvement. The aim of the current study was to predict aberrant driving behavior by traffic risk perception and intentions based on the Theory of Planned Behavior (TPB) constructs. A total of 100 students participated in the study. Three questionnaires were administrated including Traffic Risk Perception Questionnaire, a TPB based Questionnaire and Driving Behavior Questionnaire. The results indicated that intention and behavioral attitude predicted aberrant driving behavior. Age, gender and traffic risk perception were non-significant. In conclusion, behavioural attitudes towards rule compliance were more important than traffic risk perception for performing aberrant driving behaviour. The implication is to increase positive attitudes towards compliance with traffic rules through educational programmes.
item: Conference-Full-text
Factors affecting road accidents in urban areas: a case study of Nakhon Si Thammarat municipality
Yaifa, Trakulsanti; Piti, Chantruthai; Orawan, Raya; Pichai, Taneerananon
This paper describes a method for identity hazardous road location in Nakhon Si Thammarat municipality and the findings regarding the causes of the traffic accidents. The ranking of study locations were selected by using the criteria of number of critical accidents and severity index. The 3 study locations comprise Black Spot no.1 (BS-1): Robinson department store, Black spot no.2 (BS-2): Nakhon Si Thammarat Technical College and Black spot no.3 (BS-3): Thama-market intersection. Results of analysis using the Binary Logistic Regression model show that for BS-1, independent factors that are expected to influence the traffic accidents include gender, number of household motorcycles and driving with excessive speed. For BS-2, the independent variables that are expected to influence the incidence of traffic accidents include age, number of cars in a household and lack of traffic control devices. For BS-3, the independent variables are male and the age of the respondents. Recommendations are suggested to deal with the factors that influence the occurrence of the traffic accidents.
item: Conference-Full-text
The evolution of criteria for identifying black spots and recommendations for developing countries
Nguyen, Huy Huu; Taneerananon, Pichai; Koren, Csaba; Luathep, Paramet
The general purpose of black spot identification is to identify high accident frequency locations on a road network to improve road safety. The next task is to sift through these locations to select the particular locations based on whose analysis the safety treatment is established. Thus, black spot treatment is a two-stage process: identification and safety analysis, with the former producing the enriched data for the detailed analysis done in the latter. Such analysis is to determine the true black spots, the safety aspects to improve, the cost of treatment, and the extent of the efficiency. Accordingly, the object of identification stage is to select sites that have a good chance of being in need of remedial action and also capable of being cost-effectively improved. This paper reviews the evolution of criteria for black spot identification in terms of scope and aspects. On the basis of this review, a number of suggestions are made for the cases of developing countries in terms of black spot identification aspects.

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