Browsing by Author "Wiratunga, IVH"

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    item: Conference-Abstract
    A concept of weather window (WW) in managing the rain risks in construction projects of Sri Lanka
    Wiratunga, IVH; De Silva, N
    Different weather conditions such as rain, wind and snow would directly impact on the performance of any construction project. Being a tropical country, the effect from rain would 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 define by the Meteorological Department. In this research the value used' to define the wet day is modified to establish the '"weather windows• (WW.s)," 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.lt 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 scheduled by analysing the WWs, during the planning stage, even though the rain is considered as an Act of God and a totally uncertain event.
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    item: Article-Full-text
    A Concept of weather window (WW) in managing the rain risks in construction projects of Sri Lanka
    Wiratunga, IVH; De Silva, N
    Different 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..
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    item: Thesis-Abstract
    Weather risk on construction projects in Sri Lanka
    Wiratunga, IVH; De Silva N
    Almost all the activities III construction projects are outdoor, thus different weather conditions such as rain, wind and snow would directly impact on the performance of any construction project. Being a tropical country, the effect from rain would be experienced mostly in Sri Lanka. Weather risk can be defined as financial gain or loss due to a change in weather conditions over a period of time. Models to manage the weather risk on construction projects could be developed which had already been in practice in a few countries such as US and Japan. Further, such tools have transformed into new business ventures such as insurance schemes too. In these models, if rainy weather prevails beyond a certain predetermined period, contractors can claim the losses incurred by bad weather. Weather records of previous years could be studied, and a proper forecast on seasonal rainfall with Intensities (Precipitation) for current years could be assessed accurately. Then major and minor weather windows (WW) could be identified and the weather sensitive, high cost items which are at a risk are identified. Further, identification of Dry Spell, Rain Spell and Wet Spell are important for proper construction planning. This research aims in developing a strategic plan for construction projects in the planning stage so that the rain risk on the project performance could be minimized. Further, through a strategic plan weather sensitive (WS) items could be identified and avoid the WW periods within the frame work of accepted construction sequence. Finally the weather risk could make an Opportunity not a Threat provided this aspect is properly managed. Keywords: Weather Risk, Construction Industry, Precipitation, Rainfall, Strategic plan, Weather Windows