TRF - 2010

Permanent URI for this collectionhttp://192.248.9.226/handle/123/17947

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item: Conference-Abstract
Critical issues on motor insurance claims
(Department of Civil Engineering, University of Moratuwa., 2010) Edirmanne, IAG; Bandara, JMSJ; Pasindu, HR
Insurance acts as an important tool providing security to the society. As the premium paid by people are part of their savings, insurance acts in promoting savings and investments. This paper is focused on motor insurance and its critical issues in settling claims of road accidents victims. The deficiencies in transport related insurance claims, particularly, the fatal accidents, accidents at road construction sites and the growing problem of hit and run accidents are being discussed. The aim of this paper is to educate the victims of road accidents and the general public that they need not silently suffer the damages/injuries caused due to someone else’s negligence as they can always be compensated for such losses/damages through insurance claims. At the same time it creates an opportunity for insurers too, to expand their services to cover many important areas that are being highlighted. A motor vehicle accident can disrupt one’s life on many ways. This will create financial problems and emotional strain for the victim of motor accident and his/her family members. The paper identifies problems in motor insurance claims, such as; The stress of dealing with the insurance companies responsible for covering damages The insurer’s attitude to pay the minimum when settling claims Non availability of specific guide lines in settling claims among the insurers Denying policy holders’ claims Obtaining insurance policies only to satisfy the legal requirement under Motor Traffic Act People are unaware that claims have to be filed within the specified time if not, they have no claims  The victims of road accidents at construction sites and hit and run accidents could also make claims against the parties responsible, though, this is not happening in practice. The paper will also discuss the critical issues in insurance claims such as disputes between the Insurer and the Insured, obligations of the Insurer - to explain the main benefits /before the contract is entered into, exclusion of claims treatment of policy holders, legal action required to recover damage, rigid litigation procedures, responsibility of road construction contractors and safety violations, deficiencies in Hit & Run Accident Claims and benefits for victims of pain and mental sufferings. The following recommendations are identified as vital in promoting motor insurance not only among people live in urban areas but also among people in rural areas.  Awareness programs to educate the motorists. Consumer education is also important to provide the motorists with the correct state of mind for careful driving to prevent accidents. The public should also be educated on how they should report traffic accidents and also be educated on insurance matters.  Driver training and testing programs  Introduction of New Laws and Regulations  Proper guide lines and procedures in settlement of claims  Consideration of claims for pain and mental sufferings  Awareness programs regarding insurance claims for victims at road construction sites  New Payment plan for road accident victims younger than 18 years and over 65 years of age. This is a serious issue since these groups of people are not covered as they have no earning capacity.  Keep in view the no-fault claims – No fault claim should be kept in view as it has its merits and drawbacks.  On line information to minimize delays in obtaining insurance claims and to find information for people who are interested in insurance.  The successful implementation of the above recommendations depends on the cooperation of all stakeholders to play their part responsibly to deal with the issues.
item: Conference-Abstract
Determination of an effective laying pattern and best block shape for concrete block pavement based on field performance
(Department of Civil Engineering, University of Moratuwa., 2010) Senadeera, AA; Mampearachchi, WK; Pasindu, HR
There has been an intensive process of urbanization which has brought about need for rapid construction of roads and related infrastructure during the end of the last century. Therefore development of economical road construction methods is a high priority for a developing country like Sri Lanka. Concrete block paving is one of the predominant road construction method used in most of the developing counties due to economic adaptability and this has emerged as a cost effective road construction method suitable for certain local conditions. But in Sri Lanka this technique is yet to be developed to a fully fledge road construction method. This can be attributed to a dearth of the technical expertise and knowledge. As a result, there is a great need to develop knowledge and establish proper methods of block paving. The performance of concrete block pavements vary with block shape, thickness, size of the block, compressive strength ,laying pattern, bedding sand and sub grade conditions. Therefore, considerable amount of research has been done recently with Concrete Block Pavement models in order to analysis their performance with respect to various factors. But most of the researches on CBP have been done in laboratory models and very low traffic roads and these tests may not simulate real situation. This research will cover the real ground situation and the behavior and the effects of blocks due to traffic weights. Objective 1 determine most suitable individual block shape for CBP roads 2 determine effective laying pattern for CBP roads Method/design This research was covered the real ground situation and the behavior and the effects of blocks due to traffic weights with high percentage of heavy truck and buses.. Under this study, concrete blocks were cast according to the specifications in predetermined shapes and paving was done with different block shapes and patterns in a road which contains vehicular traffic. Selected 100m road length was divided to 10 equal parts and blocks were paved according to selected pattern and block shapes in each different section. Deflection was measured by using Benkelman instrument and block displacement were measured by using venire caliper. The most effective block shape and pattern were selected comparing deflection and block displacement in each combination of block shape and patterns. Findings The analysis of results show that the following results Most effective block shape is Uni style Most effective block paving patterns are Stretcher and Herring. Both show similarly good results. The effective laying angles are 0 and 90 degrees. Here again both angles show good results. Conclusions Under this study, concrete block paving road was constructed. Concrete blocks were cast according to the specifications in predetermined shapes and paving was done with different block shapes and patterns. Then the performances of the block paving were observed after allowing traffic. The data were collected to determine the most effective block shape and pattern. The most effective combination of variables for cement concrete block laying are Uni style block shape, Stretcher and Herring block pattern and zero or 90 degree block angle can be recommended for new CBP roads.
item: Conference-Abstract
Develop an evaluation criterion to assess pedestrian facilities in urban environments at micro level
(Department of Civil Engineering, University of Moratuwa., 2010) Dias, TWKIM; Bandara, JMSJ; Pasindu, HR
In urban design, facilities available for the pedestrians and the convenience of walking are the measure of the overall walking conditions in an area. The concept of walkability has been used to assess these factors. That is to measure the extent to which the built environment is friendly to the presence of people living, shopping, visiting, enjoying or spending time in an area. A walkability index is a method to evaluate the facilities available for walking. Evaluating walkability is challenging because it requires the consideration of many subjective factors. Some factors are; land use modal conflict, security, crossing safety, motorist behavior, pedestrian amenities, disability infrastructure, side walk width, obstructions, maintenance and cleanliness. There are some indices used internationally and all of them assess the effectiveness of the facilities qualitatively. In this paper it is proposed to develop a criterion to compare two roads at micro level to evaluate ease of walking with an improved walkability index. An attempt has been made to incorporate more quantitative parameters that will minimize individual biasness. It is expected that having an evaluation criterion will generate awareness on walkability as an important issue in developing cities. This will help the relevant authorities to identify the areas where the pedestrian facilities are to be enhanced. Some of the walkability indices have been evaluated and their shortcomings and limitations are being identified. For the current indices that are in use, roads environment need to be categorized in to specific types such as a high-income neighborhood with mostly housing; a low income neighborhood with mostly housing, a transport hub (e.g., rail station), and a commercial district. A survey was carried out in the Colombo city limits with a road length of 35 km. During that survey it was realized that a similar sampling method cannot be adopted and road stretches should not be greater than 500 m. to avoid loss of homogeneity since the land use is not much organized in developing country such as Sri Lanka. In order to accommodate different land use types along the road it is proposed to use the land use percentages. There is a need to incorporate the height of the buildings or walls by the road side. The effects on weather on the walkability measures were not seen in any walkability index. Evaluation need consider both rain and sun shine. This paper summarizes the findings of the walkability survey carried out and highlight the improvements need to minimize biasness.
item: Conference-Abstract
Development of content management system for traffic survey reports
(Department of Civil Engineering, University of Moratuwa., 2010) De Silva, SCP; Bandara, JMSJ; Pasindu, HR
Transportation has become one of the key development factors in Sri Lanka recently. More studies and research have been initiated relating to the transportation infrastructure development. The one of the essential parameter for these studies and research is the availability of traffic related information Since traffic data is vital for any type of study or research in transportation, the traffic survey reports files should be stored efficiently in a suitable repository from for interested party to view or use them. There are different types of surveys conducted to gather traffic related information. Efficient mechanism to store collected data and an easy access to past data is a growing requirement. Currently there are no proper ways of keeping all surveys results that have been conducted. This paper discusses the development of a content management system to handle traffic related information. A development of Content Management System for managing all common types of traffic and transport surveys is discussed. A separate file server is configured to store digital copies of survey results while end user software is connected with server and give all information about surveys. The Users can download relevant data from the server. java technology was used in developing the software and relational database management concept was used to develop the data model. The database schema is developed by identifying the basic information/data regarding to be stored from any survey type (O-D, MCC etc.) by applying the concept of relational database and EER modelling. The software development has gone through the basic steps defined in waterfall method. The final system is user friendly and safe since all the information is gathered to one central server database. Using this central server any type of survey reports can be retrieved with details. The administrator who is responsible for the system can grant the privileges to other low level users to do their tasks separately. Both functional and non functional requirements have been considered in the development of this database. As functional requirement the main processes for the system have been considered. For non functional requirement the quality of the system; security, reliability, performance, resources etc. have been considered based on the software and hardware components.
item: Conference-Abstract
Development of shortest path network with minimum nodes for the national roads to maximize the accessibility using breadth-first search algorithm
(Department of Civil Engineering, University of Moratuwa., 2010) Sellahandi, HW; Mampearachchi, WK; Pasindu, HR
Sri Lanka, as a developing country, needs data also in the form of classification for things like reservoirs, irrigation schemes, roads etc. Most of the infrastructure facilities in Sri Lanka have been built; nevertheless, they have not been classified fully into categories for further advanced studies in its own field. Roads in Sri Lanka are such as instance. Most of the Sri Lankan roads have been classified as class A, class B, class C and class D roads. Among them class A and B roads have a clear definition, whereas, class C and D roads have failed. Over the time these roads are upgraded by the government when such a demand, due to the development and increase in traffic, is faced by the relevant authorities. Sri Lankan government has made great achievement in economic and social development. One of the most important policies of Sri Lankan government has been sticking to is to prioritize infrastructures construction, including transportation, energy and telecommunication, among which, transportation especially road network was realized as vital of economic development by Sri Lankan government. However, in Sri Lanka, road of total length 72000 km are in the state of unclassified. The reason is, the objective found in constructing such road was to just connect villages and small community centers. As the time permitted us to the next stage from this level, classification of these roads is of concern. The paper is focused on development of a low volume road classification system based on minimum node shortest path concept in network analysis The sample road network was selected in Kesbewa DSD for the study. In creating the road network, all junctions were defined as nodes and all road sectors were defined as edges. Find the all minimum paths to specific goal node. This process will be continued several times. Ultimately this will come up with the most important shortest paths. According to this shortest path, the sample road network can be divided into sub networks. Breadth-first search algorithm is uses to identity the minimum node path in a subnet work. All the nodes in Class A, B, roads are marked as goal nodes in the sub network and a start node is selected from the rest. In the (Breadth-first search algorithm) program is executed and the shortest minimum node paths can be found. This process is continued to all nodes in the region excepting goal nodes. The minimum nodes path in the sub network are arranged by the descending order depend on number of minimum nodes in those minimum paths and weights are assigned to road links according to the survey data analysis. The links are ranked according to the weight range they fall in. This analysis will help to identify the most important link in a network to improve the accessibility to National road network.
item: Conference-Abstract
Economical mix design for interlocking block paving for Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2010) Pilanavithana, US; Perera, PS; Appuhami, RSBR; Mampearachchi, WK; Pasindu, HR
Rocketed trend of world wide Concrete Block Paving (CBP) adherence to the road network has already influenced the Sri Lanka as a well performing alternative for the rigid concrete pavements which caused many issues over past decades. Even though CBP in larger Production level, significant Standards and Guidelines for basic properties and manufacturing in the Sri Lankan conditions have not been introduced yet. Especially in application of CBP in trafficked road ways seems to be declined as it is not deeply concerned by the authorities due to lack of guidance. In that case the requirement of study in concrete mix design of CBP for roads phenomena was come across. In an attempt to find the a economical mix design for concrete block paving optimized combination of cementitious and aggregate materials has been developed, which contains cement, sand, quarry dust and chips in intended for the production of interlocked concrete blocks for paving in road pavement. The main purpose was to achieve optimized Concrete Blocks with fulfilling the requirements in road by using alternative aggregates, admixtures and the production cost via materials. The initial mix design was developed with the use of literature review and besides that other mix proportions were introduced by altering the initial design. First series of blocks were produced by using above mix designs by varying the aggregate-cement ratio (A/C) and water-cement ratio (W/C) between 0.25 – 0.40. Optimized value was selected considering the Compressive strength, Surface texture and Shape (edges). Next series was casted from the selected mix design and sand was replaced by quarry dust in proportion to the total fine aggregate weight. Final mix design was developed with those results and it showed significant high energy requirement compared to the first series. Seven days Compressive strength of CBP with out quarry dust was varied between 52 N/mm2 – 34 N/mm2 with in the W/C of 0.25-0.40. It was given 41 N/mm2 – 46 N/mm2 variations for the W/C of 0.30 after replacing the quarry dust with sand. This has satisfied the required strength of 35 N/mm2 for the commercial vehicles. All mix designs produced zero slumps. Compressive Strength has correlations with the A/C, W/C, Density and Sand Percentage. W/C inversely affects the shape and texture. In conclusion, Sand can be replaced by quarry dust as a successful alternative aggregate with a unique proportion. W/C ratio plays major role while restricting to upper limit to fulfill surface texture and shape. Quarry dust improves strength with a unique proportion of sand while acquiring more energy in production.
item: Conference-Abstract
Effectiveness of traffic forecasting on pavement designs in Sri Lankan roads
(Department of Civil Engineering, University of Moratuwa., 2010) Gunasinghe, PH; Mampearachchi, WK; Pasindu, HR
Since the pavement design plays an important role in any improvement or rehabilitation, it is a responsibility of the road design Engineer to ensure that he has come up with an effective design, so that it will last for the design life. This effectiveness or the optimization is very important as otherwise it could lead to financial implications. If it is under design, it will not last till the end of design life, thereby incurring huge sum of money for the early rehabilitation and maintenance. And if it is over designed, that would also be undesirable fact, as the cost over run on this could have been utilized to improve another few kilometers of road. The method adopted for the design of selected flexible pavements was the TRL, Road Note 31. The two main parameters considered in the design of the pavements under Road Note 31 are CNSA (i.e. Traffic Class) and the sub-grade strength (i.e. CBR% class). In this research study, flexible pavement designs of recently rehabilitated or improved set of roads were analyzed to check the effectiveness of the traffic forecasting on pavement design. As the sub-grade strength of the pavements is a fixed parameter in all the cases, the only possible variable is the Traffic Class relevant to predicted CNSA. It was found in the study that the actual traffic growth rates of different modes of traffic which travels along the selected roads is different to the predicted rates at the time of design. It has also been shown and statistically proved that the ESA values actually applied on these pavements by large trucks / heavy goods vehicles are significantly high, compared to the ESA values recorded at the design stage. Authors have proposed a methodology to evaluate the effectiveness of traffic forecasting on pavement designs. And improvements to the present practice of pavement designs carried out by RDA and its presentation.
item: Conference-Abstract
Effects of super pave specifies aggregate gradation on Marshall mix parameters
(Department of Civil Engineering, University of Moratuwa., 2010) Fernando, PRD; Mampearachchi, WK; Pasindu, HR
Standard specification for roads and bridges (SSCM) includes gradation master band in which upper and lower percent passing has been specified for most sieve sizes. These limits tend to make finer gradation in the asphalt concrete than Superpave specifies aggregate gradation. The objective of this research is to evaluate the effect of Superpave aggregate gradations on Marshall Mix parameters (heavy traffic condition) while types of asphalt binder and type of aggregate remain unchanged The method was very similar as Marshall Mix design procedure that SSCM are described for Sri Lankan conditions, except Superpave guides was used to develop the design-blended aggregate envelops. Locally available crushed granite and 60-70 penetration grade bitumen were identified and collected to prepare different test samples. Individual properties of asphalt binder and aggregate were tested to determine that they are met relevant specifications as mentioned in SSCM. The different hot bin aggregate samples were combined to make aggregate mixtures that comply with the Superpave conditions. The coarse side (plus 4.75 mm) of the grading curve remained almost unchanged, while the fine side (minus 4.75 mm) was varied in order to pass through, above, and below the restricted zone specified in superpave aggregate gradation. The blended aggregate envelopes were categorized as follows:  Over Restricted Zone (ORZ) with comply to control points.  Through Restricted Zone (TRZ) with comply to control points.  Below Restricted Zone (BRZ) with comply to control points. It was observed from the research that all Superpave specifies aggregates blends were satisfied the SSCM specified Marshall Criteria. Superpave restricted zone was not affected on Marshall criteria under local conditions and specifications. Optimum binder content (OBC) and Binder Tolerance (BT) were reduced when aggregate blend becomes coarser. Average Film Thickness (AFT) was increased when aggregate blend become coarser. Further, Marshall Stability and Void in Mineral Aggregate (VMA) are not any significance differences when compare three gradation envelops (ORZ, TRZ & BRZ). There was no significance different of Marshall Flow of ORZ & TRZ, while BRZ showed some lesser value than ORZ & TRZ. Air Voids (Va) value was increased when the aggregate blends become coarse.
item: Conference-Abstract
Estimation of ESAL values for low volume roads in provincial sector
(Department of Civil Engineering, University of Moratuwa., 2010) Kinigama, L; Mampearachchi, WK; Pasindu, HR
The demands for the improvement of provincial roads are ever increasing and GOSL has given priority for the upliftment of rural economy through the improvement of rural road network. Funding agencies have shown interest in providing financial assistance for this task. Road design engineers require reliable traffic data and design specifications for detailed design of provincial roads. One of the basic inputs required for the pavement design is the ESAL values for each vehicle category in each road. The most common method used for the estimation of ESAL values for trucks is the static axle load survey conducted by Road Development Authority (RDA) for national roads however the axle load surveys are rarely done for provincial roads. Sophisticated equipment and methods are not suitable for the provincial sector as their capacities are limited. Primary objective of this study is to formulate a simple but reliable method to estimate axle loads on provincial roads. The most important and core analysis of this study is to find out how the vehicle load is distributed among axles. The vehicle load can be estimated using vehicle dimensions, type of material and loading condition. Then this estimated load should be distributed among each axle in a rational manner. Again for the buses, LGVs and Farm vehicles, the average distribution of loads were analyzed irrespective of the type of loading material. This is simply because the, loading type for buses are passengers only, and for farm tractors, it is mostly grains and agricultural products. There is no large variation of load distribution for different type of material in the case of LGVs. But for the MGV & HGV types, the distributions of load among axles are very sensitive to type of material. Therefore the same analysis was extended for each material type. The method introduced for the estimation of ESAL is very straight forward and simple. High technical inputs are not required for the implementation. High-tech equipments are not required. It is quick and easy, therefore large amount if trucks can be measured during the field survey. The survey can be carried out for several days for the same road to see all the traffic variations and seasonal changes. And it can be used for all roads and then CNSA for each individual road can be found. The accuracy of the findings was checked using actual axle load survey data. It was found that results can be accepted at 95% confidence level. The ESAL is usually estimated based on the sample data. Hence, the proposed method can be used to estimate ESAL values for each vehicle category on all provincial roads with reasonable accuracy.
item: Conference-Abstract
Evaluating suitability of soil stabilization methods for local road construction industry
(Department of Civil Engineering, University of Moratuwa., 2010) Herath, HMSM; Mampearachchi, WK; Pasindu, HR
Soil stabilization is defined as any treatment applied to improve its strength and reduce its vulnerability to water. With the rapid development of local infrastructure industry, there is a scarcity of good quality soils which causes to delay of projects, increase of cost as well as decrease the quality of the final product. Therefore it is essential to find out reason for non popularity of soil stabilization and develop some guidelines to effectively used in road construction sites. A survey was conducted among professional in road industry Survey result reviled that only 35% of the participants had a fair knowledge and experience on soil stabilization but 72% and 56 % of participants were skeptical on quality control and the cost respectively. Engineering properties of soil Sample collected from different places were determined and same soil has being used to determine the properties after stabilizing according to the available guideline, with locally available stabilizers ( Cement and Lime).Laboratory test results indicates that both stabilizer improve soil properties in considerable amount and Degree of Pulverization (DOP), mixing time are important parameters in soil stabilizing .Further, field tests are conducted to measure the applicability of stabilization technology using locally available materials and machineries According to the laboratory test results shows 80% degree of pulverization (DOP) is required to gain a higher compressive strength of cement and lime stabilized soil. The effect of delayed compaction showed a strength reduction of 22% for cement and 12% for lime at the OMC. Lime and cement stabilizers increase OMC and therefore compaction should be carried at higher moisture content. .Breaking action is more effective rather than rolling action in soil - stabilizing. So, rotaries may be more effective than motor grader or backhoe (which are presently use)
item: Conference-Abstract
Finite element model analysis to determine improved support condition for concrete block paved low volume roads
(Department of Civil Engineering, University of Moratuwa., 2010) Gunarathna, WPH; Mampearachchi, WK; Pasindu, HR
The intensive process of urbanization in the last century has caused a need for rapid construction of roads and related infrastructure in Sri Lanka. The rapid demand for better roads and services required the designers and the builders to introduce suitable construction methods in order to economize the construction as well as increase the durability. In Sri Lanka, large percentage of low volume roads has been constructed using gravel, concrete or bitumen as the primary material. Due to lack of maintenance of the roads in rural sector, Engineers are trying to find alternative cost effective pavement construction techniques. Concrete block paving (CBP) is one of the predominant road construction methods used in most of the developing counties due to economic adaptability. This method can be emerged as a cost effective road construction method suitable for different ground conditions with low life cycle cost. However, this technique yet to be developed to a fully fledge road construction method in Sri Lanka. Therefore, standard set of guide lines are needed to maintain consistency and construction quality of block paving technology. The aim of this research is to evaluate the state of support conditions for low volume roads and effective block laying patterns which can be used to obtained best performance from concrete block paving. Therefore verified three-dimensional (3-D) finite element model (using SAP2000 structural analysis software) was used to measure elastic deflection behavior of concrete block pavement for low volume roads. Developed design chart can be used for subgrade improvements for low volume roads condition and find best laying arrangement in the concrete block paving to obtain most excellent interlocking action.
item: Conference-Abstract
Freight vehicle movement pattern on national roads in Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2010) Priyadarshani, GAC; Bandara, JMSJ; Pasindu, HR
Transportation in Sri Lanka is mainly based on the road network which is centered on Sri Lanka's capital, Colombo. It is reported that over 95% of the freight movements are taking place on roads. However, majority of the studies focuses on passenger transportation and minimal literature available on freight transportation in Sri Lanka. Objective of this paper is to analyze the freight vehicle movements in Sri Lanka in various aspects such as vehicle type, type of commodity, load and capacity. This study uses the roadside origin and destination survey data collected from 35 locations all over the country by the Transportation Engineering Division of University of Moratuwa. First the data from the 35 locations were analyzed qualitatively and quantitatively to find which type of vehicle mostly uses for freight transportation and the type of commodity highly distributed and find whether there is any correlation between commodity type and the type of vehicle and loading patterns. Next part is, preparing a combined origin and destination matrix to find the freight trip distribution pattern. When preparing combined origin and destination matrix at Divisional Secretariat Division (DSD) level, it is found that most of the cell values are zero. It may be due to inadequacy of sample sizes or there is no freight trips during the time of data collection or those trip may not be going through the selected survey locations. Hence, the combined origin and destination matrix was prepared for District level, It is found that 69% of the freight vehicles are medium goods vehicles while light goods vehicles and multiaxel goods are 19% and 6% respectively and remaining 5% are heavy goods and tractors. Except within the Colombo district trips most of the medium goods vehicles trips are moving from Gampaha district to Colombo district. When considering the commodity type it is found that 38% are empty goods vehicles, 10% are construction materials the remaining 14% are perishable and other agricultural products and the remaining 38% are other types of goods. It is also found that 46% are empty loaded vehicles, 25% are fully loaded and remaining 29% are 1/2 loaded, 1/4 loaded and overloaded vehicles. With respect to the total freight vehicle combined matrix, it is found that 36.9% trips are generated from Colombo district and 53.2% trips are attracted to Colombo districts. Finally it is found that most of the perishable goods are fully loaded and medium goods vehicles are mostly used to transport the perishable goods.
item: Conference-Abstract
Geometric design standards for narrow curves in hilly terrain of Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2010) Salawavidana, ST; Mampearachchi, WK; Pasindu, HR
The geometric design standards of roads in Sri Lanka are primarily based on the ‘Geometric Design Standards of Roads (GDSR) of Road Development Authority, 1998. The GDSR is a complete set of guidelines that the Highway Design Division of RDA is following to design new roads and rehabilitate existing roads. However, the problem identified in this research with this glorious manual is the lack of design details for the horizontal curves whose radii are below 25m. As a design engineer, a main problem one faces in designing the roads in Sri Lanka is the financial constraints imposed with the design. Even though one is obliged to follow the GDSR in designing roads, it is common to find places where the minimum curve radius 25m is not possible at all without significantly increasing the cost. The aim of this research is to find out a set of guidelines for the geometric design standards for these narrow curves. The main objectives considered are; to find out the horizontal design standards, in the context of design speed and superelevation that are adoptable to the curves whose radii are below 25 m, to find out the appropriate vertical design standards to cater the above situation and to find out the different physical measures to enforce these design standards. The Factor of Safety (FOS) was assessed in each of the speeds from 100kmph to 30kmph as used in GDSR. A representative FOS was taken to use in design speeds lesser than 30kmph. The maximum superelevation was assessed subjected to the practical maximum of 10% as per the findings from the literature review. Side Friction Factor (Fmax) was taken as 0.21 in conformity with the findings from the literature. Minimum radii for each of the superelevation values from 2.5% to 10% were determined against speeds of 25kmph, 20kmph, 15kmph and 10kmph. The practical minimum radius of 13m was adhered to cater for the design vehicles. It is shown that the derived design standards can be used for the narrow curves up to 13m, which are not covered by the GDSR and they should be accompanied with suitable vertical design standards. The practical minimum design radius should be 13m.
item: Conference-Abstract
Guideline for the selection of appropriate specifications for low volume roads
(Department of Civil Engineering, University of Moratuwa., 2010) Wannige, EP; Abeywardena, HST; Haththotuwa, HMDS; Bandara, JMSJ; Pasindu, HR
The paper presents the research carried out to prepare a set of guidelines for the selection of appropriate specifications for low volume roads. It is an essential requirement to have such a guideline because lack of such guideline has resulted in waste of valuable resource in road construction work. This research finding are very important to Sri Lanka as there are many problems associated in the low volume roads due to lack of technical knowhow of the majority of people involved in the low volume road construction and maintenance. This paper describe the work is carried out in order to provide a guideline to minimize existing problems. For the purpose of selecting suitable specifications for low volume roads a wide range of data base was needed. Areas selected for data collection were Badulla, Diyathalawa and Mahiyanganaya Engineering divisions in Uva Province. With the purpose of having a good database for analysis, data was collected through both discussions with engineers in provincial Road Development Department in Uva Provincial Council and observed data through field visits. Practice of low volume road planning, design and material selection, construction and maintenance were discussed with engineers and important road sections for visits were identified. Through field visits data on various parameters affecting the road condition were collected including all road types such as DBST, gravel, concrete and metalled & tar. The data collected was statistically analyzed using SPSS software to identify significant relationships are present between parameters identified as important. The identified important parameters were drainage condition, traffic volume, terrain, land use, material used and carriage way width. Crosstab analysis was carried out between two parameters and also in between more than two parameters using layer option available in SPSS. Results of the data analysis were used for producing the set of guidelines for planning, design and material selection, and construction and maintenance phases. A GIS map was also produced to indicate the existing road conditions as a tool for identifying access needs during planning process of roads. A sample inventory of road infrastructure is presented to demonstrate how to use collected information during planning, design, and construction and operation stages of low volume roads.
item: Conference-Abstract
Identification of suitable decision support system for planning programming and economic evaluation of road investment projects for Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2010) Sumugan, VS; Kulasooriya, KASA; Bandara, JMSJ; Pasindu, HR
Project evaluation, especially road investment project evaluations need to be handled carefully, since the initial capital outlay for such projects is considerably higher than other projects and it is highly essential for the national development. In Sri Lanka we can observe a lack of data for the evaluation process and the absence of suitable decision support systems although we have observed some developments such as the HDM-4, PREM model, and information systems such as TransPlan which are used widely. This research targets at identifying the current trends in the evaluation process and to identify critical parameters which affect the evaluation to further improve the quality of decision making in the sector. The paper first identify the economic and engineering evaluation techniques currently used in the industry. NPV, IRR and Cost Benefit Analysis were the primary economic indicators used. Based on these and the available data it was decided to identify critical parameters that affect these indicators and to identify suitable evaluation methods. For this purpose HDM-4 was used. HDM-4 (Highway Design and Maintenance Standards Model) was developed by the World Bank. It combines the technical and economic appraisals of road investment projects and is highly reliable. The application has a single drawback with respect to the local environment, i.e. it requires a high amount of data. Therefore in order to comply with the standards a sensitivity analysis was carried out to identify the most critical parameters that will affect the output significantly. Several data sets were used with input data such as drainage condition, traffic data, pavement condition (Roughness, CBR etc.) and others to identify the impact of these factors in the evaluation process. Using the results produced over a range of input data, this paper identifies critical factors that need to be measured accurately to minimize significant deviations in results with respect to the actual situation. Furthermore it also targets at identifying a way to coordinate the existing information systems present to aid in the evaluation process. The result expected is a much better, accurate, reliable and transparent decision making process than at present in the local context.
item: Conference-Abstract
Method to identify potential safety deficiencies at identified accident black spots
(Department of Civil Engineering, University of Moratuwa., 2010) Jayawardena, G; Bandara, JMSJ; Pasindu, HR
Accidents Black spots are the locations or road sections where accidents are common. Highway engineers and Traffic police generally know of the tendency for road accidents to cluster together at certain locations, commonly termed “accident black spots”. It is possible to identify these black spots of the road network, so that appropriate remedial measures can be undertaken to reduce the likelihood and severity of accidents at those locations. Although the improvement of accident black spots is a very important area requiring attention it has so far received little priority in Sri Lanka. Traffic accidents are a serious issue in Sri Lanka around 2,000 people are killed in traffic accidents every year. As a result of ever increasing number of vehicles and insufficient safety precautions the traffic accidents in Sri Lanka shows an ever increasing trend and the alarming numbers of fatalities. The objective of this paper is to provide a clear guidance on how to enhance the road safety at identified accident black spots by identifying potential safety deficiencies in Sri Lankan road network. At present, Sri Lanka Police Department keep records of traffic accidents, but this information does not carry adequate information on accident prone locations or information is not properly transferred to road authorities who design and install road safety facilities. It is not clear who is the primary agency to formulate road safety policy and strategy and design and implement road safety measures. Paper identifies five major issues and their sub issues which caused to accidents in Sri Lankan road network. The five issues are i) Road markings, ii) Signing and lighting, iii) Layout geometric details and road surface, iv) Pedestrians and related facilities, v) Overtaking opportunities and land use either side of the road. Significance of these issues can be change depending on the location and the environment. Method has been proposed to priorities these major issue, as most of our organizations are not in a position to rectify all identified problems, due to restricted/lack of funds. Furthermore, under each issue it is identified sub factors which can enhance the accident situation. The above major issues and sub issues are gathered in a questionnaire format. Major contributing factor can be identified using the said questionnaire for a particular problematic location. As mention above the questionnaire has been based on five different issues with their individual sub components which has been identified as the important safety factors in Sri Lankan Road Network. The questionnaire needs to be answered by different people at the conflict location (Safety Audit). It is advisable to do this Safety Audit by the persons who have some knowledge regarding the road conditions and road situations. The next step is to allocate weights to individual issues. Depending on the location and the importance of the individual issues weights can be defined. As the aim is to improve road safety at identified black spot another third person who has experience in road safety improvement has to decide the weights considering the relative importance of the five issues in that particular accident black spot. Defined weights could be justified using the analytical hierarchy process. The basic idea of the approach is to convert subjective assessments of relative importance to a set of overall scores or weights. Then by normalizing the issues most critical issue for the particular location could be identified out of five issues. Subsequently most appropriate traffic safety measures could be implemented successfully. The proposed method will enhance the road safety at identified accident black spots with less cost but effective safety measures resulting more economic benefits to the society.
item: Conference-Abstract
A methodology for design of pedestrian crossing facilities in Sri Lanka
(Department of Civil Engineering, University of Moratuwa., 2010) Kaluarachchi, S; Kumarage, KAS; Pasindu, HR
Accommodation of pedestrian should be an integral part of any transport infrastructure design project. Pedestrian facility comprises with walkways and pedestrian crossings. Pedestrians have a right to cross roads safely. Therefore road designers have a professional responsibility to plan, design and provide safe walking and crossing facilities in their designs. Analyses of recent accident studies have identified that pedestrians comprise a significant proportion of serious injuries and fatalities while they were crossing the road without using a designated pedestrian crossing. Majority of pedestrian accidents occur while negotiating a road crossing, hence provision of safe and effective pedestrian crossing facilities are paramount. Sight distance, level of service and delay to pedestrians are major parameters to be considered with warrants prior to installation of a pedestrian crossing. Introduction of a crossing without following a rational design approach would create additional delays and such a provision would even be hazardous. It is important to recognize the correlation between pedestrian travel characteristics, with parameters such as speed, density, flow and space by conducting comprehensive pedestrian surveys. Design of a pedestrian crossing requires basic understanding of related human behaviors, characteristics and capabilities which again depend on age, physical and mental condition of pedestrians, who are expecting to negotiate a crossing. So the main objective of this study is to develop a guideline to assist in determining the appropriate crossing facility for a given location of a road based on the sight distance, Level of Service, delay to pedestrians and vehicles, pedestrian speed, density, flow and space in addition to the warrants.
item: Conference-Abstract
Methodology to determine the optimum logistics cost cluster size of multiple facility and server system
(Department of Civil Engineering, University of Moratuwa., 2010) Perera, KPH; Bandara, JMSJ; Pasindu, HR
Majority of suppliers of material required for construction are concentrated in to a particular area to handle their facilities due to the location of existing customers, existing supplying capacity and the locations of their key requirements such as raw material suppliers or sites. The market demand for a particular facility can be exceeded due to the existing demand and due to the growth of facility consumers. So the competition of the market can also be increased. This will encourage the forming of new facilities or plants and also increasing the supplying capacity of existing facilities or plants. With time facility providers can be scattered over a large area with continuous growth of the facility consumers and there is a need to determine the optimum location for new facilities. This type of problems is usually handled by using clustering method to improve the convenience and the efficiency of operation. The usual practice is to consider the geographic basis or arbitrarily based on suppliers and consumers. When there are interactions among the clustered facilities and/or between the facilities and a central server, the cost of transport & logistics operations would be a significant component that affects the efficiency of the system. The problem of locating regional facilities and allocating customers to optimize the cost of transportation covers the core topics of optimums logistic cost cluster model. This paper describes a mathematical model that can be used to determine the optimum location and cluster size for a given facility. This model can be applied in to transportation requirements which based on direct shipment network type such as construction sites of contractor, distribution network of retail stores and serves etc. Transportation problem theories and center of gravity methods were used to develop the model. The cost of transportation was assumed to be proportionate to the distances between the origin and destination. This was later relaxed by using an individual time factor which user can define according to the average speed of the particular road. Operation requirements also introduced to enhance the model accuracy and efficiency such as the concrete delivery time of concrete transportation etc.
item: Conference-Abstract
Methodology to find alternative paths using GIS
(Department of Civil Engineering, University of Moratuwa., 2010) Silva, SA; Bandara, JMSJ; Pasindu, HR
In recent years Sri Lanka has experienced a high growth in urban population and the number of private vehicles. Most evident feature of such a trend is urban road congestion; roads in some areas are also facing unexpectedly high traffic flow which causes a lot of time waste in transit and huge losses to the economy of the country. Therefore, it is important to find alternative routes during times of traffic congestion. GIS technology can be used for this purpose, to find alternative paths between two nodes and graphically represent it. This will not only help manage the existing highways efficiently but will also help traffic planning studies. Alternative path between two nodes can be node independent or link independent. Furthermore, the meaning of the node independent path is path which cannot go through specific node or nodes in its best path. The route which is not use a particular link or links of its best path can be defined as link independent path. These paths are important for transport engineers and urban planners in accessibility studies, disaster management and traffic management work. Best path between any two nodes can be found using minimum path algorithms. TransPlan model developed by the Transportation Engineering Division of the University of Moratuwa facilitate finding best paths between any two nodes on the National Road network in Sri Lanka. It is not possible to find alternative paths between two nodes using TransPlan. The objective of this study is to develop a method to find the node independent and link independent alternate paths using Geographic Information System (GIS) and make a model to find the alternative paths of A, B and selected main roads within City of Colombo by customizing the ArcGIS network analysis tool using Visual Basic 6.0. Method used and examples of application are presented in the paper.
item: Conference-Abstract
Methodology to identify the optimum network for an integrated urban rail system
(Department of Civil Engineering, University of Moratuwa., 2010) Malkanthi, LPS; Bandara, JMSJ; Pasindu, HR
Planning of railway network is very important in case of new railway systems such as urban Light Rail Transit (LRT) and Mass Rapid Transit (MRT). The general objectives of a railway network development are minimizing total cost that includes construction and operation costs, maximizing social welfare and profit and minimizing travel time and negative environmental impacts. The question in transport network design is to determine a network that has an optimal performance given a specific design objective. According to the previous research studies, a methodology has been developed to identify the optimum railway network, by considering the factors related to the construction cost and the passenger demand. Although the network can be optimized by considering those two factors, it is not completed until the operational stage costs are considered. Therefore it is very much important to consider the operational costs in developing methodologies to identify the optimum railway network. This papery is on finding an improved methodology to determine the optimum rail road network considering the fleet cost in addition to the construction cost. Optimum route network is generated so that optimizes the fleet because fleet is mainly depending on the route network. Initially, ten locations form the Colombo Metropolitan Region are selected as station locations and two networks are identified based on two scenarios. First scenario is to generate a primary route network considering the demands between nodes. Routes are assigned for highest demands until all the nodes are connected at least by one route. In second scenario, all the demand values between nodes are assigned along their shortest paths and add them up to calculate the total demand for each link. Primary network is generated by linking the highest demand links until all the nodes are connected. Routes are assigned for the network considering the highest demand. The two route networks are checked for fleet cost. Route networks are fine tuned using a set of algorithms for route merging, adding links and route sprouting. Fine tuned route networks are also checked for fleet cost and compared. Network with least fleet cost value and least changes for fleet cost with route network changes is selected as the best network. That means the best network should not be changed considerably in the later stages of operation due to demand variations apart from adding links or changing route network. The method to generate the best network is considered as the methodology to find the optimum network.

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