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- item: Article-Full-textTowards great streets: an empirical approach to study a streetscapeMeetiyagoda, L; Munasinghe, JThis paper presents an attempt to device an empirical method for streetscape analysis. The need for such method is felt in a context that designing streets has been an area of wider concern but without adequately developed guides. Improving streets and their qualities necessitates an appropriate understanding of their presently available characteristics and therefore, demand robust methods for that purpose. The method presented in this paper is evolved upon Alan Jacob specified ‘requirements’ for a ‘great street’. It demonstrates a process for the evaluation of a streetscape in relation to a set of physical attributes, derived from Jacob’s requirements. The attributes are derived though diagnostics analysis of the requirements with the support of the other literature available in this area. Their strength is tested in a selected street segment of the Galle Road in Sri Lanka.
- item: Article-Full-textAn Assessment of off-grid micro hydro potential in Sri LankaFernando, S; Senarath, R; Ananda, R; Sarath, DBViability of using off-grid micro hydro technology for rural electrification was first demonstrated by the Intermediate Technology Development Group (ITDG) in 1991. Following the demonstration phase, ITDG carried out numerous activities to create the enabling conditions for replication of this technology on a wider scale. The technology has gained popularity in Sri Lanka and its application is steadily growing.
- item: Article-Full-textIndustrial pollution reduction programme : waste minimization project at DCSL SeeduwaAmarasinghe, BMWPK; Fonseka, PNP
- item: Article-Full-textDevelopment of a prototype DS-CDMA SystemAbhayawardhana, VS; Hunukumbure, RMM; Dias, DThis paper describes the development of a prototype Direct Sequence Code Division Multiple Access (DS-CDMA) system. The main objective of the work was to design and implement a CDMA system, based on its fundamental theoretical concepts, and thereby gain a clear insight into its operation. A secondary objective was the development of a unit to be used for the demonstration of the salient characteristics of CDMA in a laboratory'. CDMA is a form of spread spectrum communication. Spread spectrum communication, was originally developed as a technique for achieving jamming-resistant military communications. In recent years, CDMA has gained widespread popularity in commercial applications due to the massive capacity gains it promises over conventional FDMA and TDMA techniques. Despite being the newest digital air interface, many telecommunications standards bodies have defined standards based on CDMA technology for modern fixed, cellular and personal communication systems (PCS). Today, it is in fully-fledged deployment in a wide range of applications from high capacity cellular systems to ingenious position location schemes. Therefore, familiarity with CDMA is essential for today's communication engineer.
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- item: Article-Full-textDeveloping a database for timber used in Sri LankaHettiarachchi, MTPUntil recently timbers used for Structural purposes were limited to timber species that had been “tried and tested” over a long period of time. Today, however, these timbers are scarce and expensive, and it has become necessary to use either lesser known indigenous timber species or imported varieties of timber. The lack of easily accessible information on the local varieties of timbers has led to a reluctance by some potential users of timber to use the indigenous varieties for structural purposes. Information relating to different aspects of nearly 300 indigenous species is available from different sources. There is however a need to collate and integrate this information and present it in an easily accessible single source. A database is a suitable form of storage of the information, since it not only stores the information in an easily retrievable format that can be updated but also can be queried, to select suitable species for specific end uses or to find suitable end uses for a given species.
- item: Article-Full-textThermal performance of free-running three-storey houses: an assessment through computer simulationsJayasinghe, MTR; Attalage, RA; Jayawardena, AISri Lanka is presently facing a serious energy crisis due to continuous increase in energy demand annually. One of the solutions for this is energy conservation for which houses are a good candidate. The need for using active means such as fans and air-conditioning can be minimized by planning the houses with desirable passive features. In order to determine the passive performance, computer simulations were carried out for two houses with and without passive elements. A comparison of similar volumes in these two houses indicated that it is possible for the indoor temperature of certain type of volumes to rise about 5°C above the maximum outdoor temperature when passive elements are ignored.
- item: Article-Full-textQuantification of the thermal performance of free-running three-storey housesJayawardena, AI; Jayasinghe, MTR; Attalage, RAThis paper explores the possible means to adopt environmentally-friendly passive techniques to promote thermal comfort inside houses with the view of minimizing the use of energy-intensive active means such as fans. This could reduce the operating cost of houses, growth of demand for electricity in the domestic sector and adverse effects on the environment resulting from human settlement. A three-storey passive house that could be proposed on the basis of qualitative studies was selected for the quantification of its thermal behaviour, using DEROB-LTH computer program, varying the surface colour of the roof, walls and floors. The same house was again simulated after removal of its passive features such as shading devices and balcony roof, and addition of undesirable features such as west-facing windows. For all cases, the same set of probable internal loads were used. The results indicated that the indoor temperature of a functional space of a passive house can be lower as much as by 5°C than that of the same space of the same house containing features that are thermally undesirable. The results also show that, in a passive house, the indoor temperature can be maintained below the maximum outdoor temperature, which occurs around 2 p.m. This is a significant finding that guarantees benefits at both individual and national level if passive techniques are adopted by a sizable population of the country.
- item: Article-Full-textOrientation of roof and openings: their influence on indoor thermal comofrt of single-storey housesJayasinghe, MTR; Priyanvada, AKM; Jayawardena, AIAt present, the selection of the roof type and roof orientation for houses is primarily based on cost and aesthetic considerations, without much regard to the thermal performance of the roof. However, since Sri Lanka is a tropical country, the roof causes significant adverse effects on the thermal comfort indoors and therefore its thermal performance should be carefully considered on selection of the roof type and orientation. Otherwise the resulting warm indoors will cause the occupants to use fans. This is not a healthy development due to the energy crisis the country is now facing. Another aspect that deserves attention is the orientation of openings. This paper investigates the effect of the orientation of the roof and the openings on the indoor thermal comfort of single storey houses. Two roof types commonly adopted in Sri Lanka are considered, namely cement fibre roof with cement fibre flat ceiling and cement fibre roof with sloping cement fibre ceiling. Using DEROB-LTH computer program, a four-room model house was simulated. For two roof orientations, i.e. the ridge along east-west and the ridge along north-south, the simulations were carried out for March, June and December, when different extremes of sun path occur. The results indicate that the roof orientation is not so significant as the orientation of openings on the indoor thermal comfort in single storey houses.
- item: Article-Full-textPassive concepts for improvement of thermal an visual comfort in houses in Sri LankaJayawardane, AI; Jayasinghe, MTR; Attalage, RAOne of the primary requirements of houses constructed in hot humid climatic conditions such as those prevailing in Sri Lanka is that those should be thermally comfortable for the occupants throughout the day and around the year. Most of the single and two storey houses constructed in Sri Lanka have failed to fulfill this requirement. Therefore, a critical review was undertaken to develop passive concepts that can be incorporated in the future houses. It is shown with a detailed study that three storey houses can perform much better than single and two storey houses not only with respect to thermal comfort, but also with respect to visual comfort, functionality, minimisation of flash floods, creation of a desirable micro climate etc. It is also shown that the cost of three storey houses can be in the range of that of the single and two storey houses, when the traditional construction materials are used in an efficient manner. The use of these concepts for houses built in the future in Sri Lanka will be extremely important in order to minimise the electrical energy required for operation of houses; this will be quite useful since the electrical energy sources available for Sri Lanka are limited.
- item: Article-Full-textA Concept of weather window (WW) in managing the rain risks in construction projects of Sri LankaWiratunga, IVH; De Silva, NDifferent weather conditions such as rain, wind and snow would directly impact on. , th, e performance of any construction project. Being a tropical country, the effect from rain wou I be experienced mostly in Sri Lanka. Within this context, risks caused from rain can be defined in financial terms as a loss or gain due to a change in weather conditions over a period of time. Weather records available in the Meteorological Department of previous years are analysed to establish the different rain risk categories based on dry spell, rain spell, and wet spell which are derived from a “wet day ” as defined by the Meteorological Department. In this research, the value used to define the wet day is modified to establish the "weather windows (WWs),” under above rain risk categories, namely as major weather window, moderate weather window and minor weather window. These established WWs are applied to a completed project and analyzed at different risk conditions. It was identified that the concept could be used effectively to manage the rain risks. The results showed that 3.5% of the total project cost would have been saved, if the weather sensitive items such as excavation and earth works, landscaping and external works, etc., of the project were sheduled by analysing the WWs, during the planing stage, even though the rain is considered as an Act of God and a totally uncertain event..
- item: Article-Full-textImplementing value stream mapping tool in the construction industryVilasini, N; Gamage, JRThe purpose of this is paper is to understand the applicability and adoption of the value stream mapping technique in the construction industry. The applicability of the adopted value stream mapping methodology was tested in a pre cast concrete yard which supplies pre cast concrete yard which Supplied pre cast concrete segments to a bridge construction site. A process mapping tool has been used for value stream mapping since it contains high correlation to the existing wastes at the sites. A detailed value stream mapping procedure was developed and validated within this case study. The effectiveness of the value stream mapping methodology was also evaluated at the same site as it was producing approximately five hundred units continuously. The research findings will contribute to a better understanding of the applicability and potential benefits of value stream mapping tool in terms of cycle time reductions and quality improvements.
- item: Article-Full-textEvaluation of stakeholder satisfaction in Tsunami damaged school reconstruction projects in Sri LankaSandanayake, YG; Dissanayake, DMSCSri Lanka is one of the worst affected countries by 2004 Tsunami, which destroyed two third, of the Island's coastline. This necessitated massive reconstruction drive for recovery in all sectors including housing, healthcare, educational and infrastructure. Achieving stakeholder satisfaction is the key for the success of any project and disaster reconstruction projects are of no exception in this regard. The reconstruction of schools has been virtually completed but it is not yet known whether the stakeholders’ interests have been properly addressed. This study therefore aimed at evaluating the stakeholder satisfaction in tsunami damaged school reconstruction projects in Sri Lanka. A literature survey has been carried out on the Tsunami phenomenon, historical facts of disasters in Sri Lanka and damage due to 2004 Tsunami. Data gathered from preliminary interviews and literature survey was used to establish factors of stakeholder satisfaction in questionnaire survey. Data collected using the questionnaire survey was then analyzed using Box Plot analysis. The research reveals that the stakeholders of all categories are satisfied with most of the factors especially with the physical reconstruction aspects such as standard of school buildings, adequacy of classroom and infrastructure facilities, adequacy of disaster preparedness measures and child friendly zoning of buildings. But measures such as disaster early warning systems, practice of warning drills and persistent attention on trauma counselling for affected victims were found to be wanting
- item: Article-Full-textThe effect of textual complecity of contract clauses on contractual disputesRodrigo, VAK; Rameezdeen, RThe heart of every’ construction project is a contract, which plays a dominant role in preventing and resolving disputes by providing comprehensive coverage of all the items of work, duties and responsibilities of the contracting parties, and conflict resolution mechanisms related to all contingencies. By developing an acceptable level of communication among parties through standard and particular contract clauses, a smooth functioning of a construction project without contractual disputes can be achieved. Textual complexity’ can be described as the difficulty of a text to read and understand it by the users. Readability is text-centred; while understandability measures text-reader interaction and is a broader concept. Readability thus measures the textual difficulty’ of a passage; while understandability measures the ability of a reader to gain knowledge from a text, and is contingent not only on syntactical difficulty, but also on reader characteristics such as the reader's background, prior knowledge, interest, and general reading ability. The readability together with understandability’ will offer a better measurement on the level of textual complexity. The author identifies that the textual complexity of contract clauses in terms of readability and understandability has a relationship with the frequency of referring to them in contractual disputes. When the readability and understandability of contract clauses are low, the frequency oj those clauses being referred to in contractual disputes increases. Further, the study revealed that even though the particular conditions are prepared with the intention of making the contract clauses easier, the readability of them become more low and complex at its alteration.
- item: Article-Full-textFactors affecting construction safety management in Sri LankaKanchana Priyadarshani, GH; Karunasena, GSafety at work is an important fact at construction sites. The subject of safety attitudes and safety performance of both management and workers in the construction industry is even more so. In general, accidents at work occur either due to lack of knowledge or training, lack of supervision, lack of means to carry out the task safely or alternatively, due to an error of judgment, carelessness, laziness or total irresponsibility. The standards on quality of physical working conditions were developed based on the lessons accumulated on past accidents and are still based on the investigations and follow-up measures taken after accidents occurred at site. Thus the purpose of this paper is to explore the key factors affecting to Construction Safety Management and utilize the data to enhance the involvement of management to construction safety. The literature survey identifies the key factors affecting to the Construction Safety Management as a whole. To achieve the degree of significance of each factor affecting to the Construction Safety Management in Sri Lanka, a questionnaire was developed and sent to a random sample of top Sri Lankan construction companies. Relative Importance and the Mean Score were calculated to rank the key factors according to their importance. Through this method, it has been identified that the following factors like Management Commitment, Implementation of Safety Supervision Management Measures (Safety Meetings and Safety Training etc.), Project Nature, Jndividua, Involvement, and Economic Investment on Safety are mainly affecting to the Construction Safety Management. The final results enable how to enhance the safety performance of the management with greater involvement.
- item: Article-Full-textStakeholder management in relocation and reconstruction of public school buildings affected by Tsunami disasterRanatunga, RMP; De Silva, L; Hadiwattege, ChandanieDisaster reconstruction is a challengeable job in the construction industry. As it influence, and be influenced by many stakeholders. Stakeholder management is one of the major important disciplines in construction industry projects. This is further emphasized when projects are large and complex by nature such as Tsunami reconstruction. This research starts with basic definitions of the concepts of stakeholder management. It then explores the process involving stakeholder management in disaster reconstruction projects after Tsunami. Case studies were used as the methodology for the research. The semi structured interviews were used to establish the perceptions and the importance of stakeholder management and their impact on project performance. The examination of previous projects by documentary survey was done to identify the relationship and level of stakeholder involvement. The literature review related the findings with research and theories. The findings of research concluded that a large percentage of the delays, difficulties and cost overruns are attributed to risks related to poor needs identification by stakeholders and the absence of clear strategies for risk and stakeholder management. The Author recommends that proper stakeholder management is an important measure for the success of project delivery. The Author further recommends that proper monitoring and coordinating, risks and uncertainties are the key factors to ensure successful project delivery in disaster reconstruction. This approach necessitates the identification of key stakeholder in the project environment at the outset of the project.
- item: Article-Full-textDisability access in public buildingsKeerthirathna, WAD; Karunasena, G; Rodrigo, VAKRapid ageing, rise of wad accidents, manmade and natural disasters debilitating medical conditions and often invisible ailments cause more and more people with lowered ability to move freely. This is equally applicable to Sri Lanka which is adversely impacted by 30 years civil war and there are an estimated 900,000 disable people which mean around 5% disabilities from the population. In this context it is vital to provide them with basic facilities to live independent lives on an equal basis with others and acquire their contribution to national economic development through employing them in effective manner for sustainability. Sustainability in built environment involves promoting efficient buildings and minimizing their burden on environment, involving them on contribution of economic development, while protecting and restoring green systems, and enhancing the well-being of all people in general. Therefore it should focus on barrier free environment when designing buildings. Whilst discussing for the creation of barrier free environment, it has been created some draw backs focus on most people neglect the disability access when planning and designing. Within this context this paper presents existing facilities available for disability access in public buildings in Sri Lankan context including critical review on available policies for building design for disability access. Comprehensive literature review, pilot survey and industrial survey was carried out to assess the disability access in public buildings such as banks, educational, hospital, office and administration, railway and bus stations and results revealed that the attention paid on disability access in public buildings were not up to the satisfactory level.
- item: Article-Full-textCapacity building towards sustainability: context of post disaster waster managementKarunasena, GConcept of Capacity Building is an essential component in development theory and practice. In developing countries, it is identified as a key concept in achieving sustainability. In particular, in post disaster scenarios, focus has been placed upon local capacity building as a means of increasing resilience to natural hazards. In this context, this paper focuses on concept of capacity building and its role on achieving sustainable post disaster waste management. A literature review and pilot study have been conducted to gather information on post disaster waste management in Sri Lanka. Semi-structured interviews were held as the main data collection method and content analysis was used to analyse collected data. Unavailability of a centralized body, poor implementation of rules and regulations; lack of skills and confidence, inadequate funds, lack of communication and coordination were identified as prevailing capacity gaps in post disaster waste management. Thus, finally paper proposes a framework for capacity building for sustainable post disaster waste management.
- item: Article-Full-textConstruction procurement selection: comparative study of public sector vs. private sectorJayasena, HAEC; Rameezdeen, RConstruction procurement selection has been a major research area in recent past. Lots of researches have considered procurement selection by considering the overall construction industry as a one unit. Almost all the previous studies have identified the factors affecting procurement selection but a client wise consideration has not been carried out (Public sector vs. Private sector). Eg: Love et al, (1996), Masterman, (1992), NEDO et al, (1985), Luu et al., (2003), Chan et al, (2001). Since public sector and private sector play equally important roles in the construction industry, factors affecting procurement selection should be separately identified for each sector. Major reason for that is, although there are lots of procurement selection parameters have been identified, the importance level of those factors to the public sector selection may differ from private sector selection. That importance level can be very vital in selecting different types of procurement. Three rounds of Delphi surveys were conducted, to extract a set of exclusive factors and their levels of influence on public sector and private sector and to identify the suitability of available construction procurement options for each sector, with participation of a panel of experts who are engaged in procurement selection in the construction industry.
- item: Article-Full-textConstruction quality : Sri Lankan contractors perspectiveJayarathna, WTL; SenaratneIn today' changing environment, quality is the key to an organisation's success Many construction organisations have turn to adopt quality as a reliable management tool With this perspective, the research problem is articulated for this study as follows: How does the Sri Lankan construction contractors identify and utilize quality m their organisations . The research methodology adopted for this study was qualitative, within which case studies were used to investigate the research question. The primary data collection technique used in the case studies was semi structured interviews. Content analysis and cognitive mapping techniques were used to analyze primary data. The study identified several causes for poor construction quality and current practice of quality planning. The ISO 9000 quality’ management system ,s the most widely practicing or almost only system practicing in construction organisations, as it is a mandatory requirement acted by the ICTAD (Institute for Construction Training and Development). It was also identified that Sri Lankan construction industry is less exposed to new quality approaches such as total quality management, six sigma and benchmarking and etc. Several prerequisites for successful implementation of strategic quality planning in Sri Lankan context are also proposed including a strategic quality framework for construction organisations.