Papers by Gopinath Kathiravelu
This research involved an investigation into the influence of land use type and rainfall intensit... more This research involved an investigation into the influence of land use type and rainfall intensity on urban stormwater quality using rainfall simulation techniques. The experimental component of the study was undertaken in urban catchments located across the Sunshine Coast in Australia. Initially, a review of the physical characteristics of rainfall, and the different raindrop measurement techniques was undertaken to identify the parameters required to ensure reliable and robust raindrop and rainfall measurement. Early manual raindrop measurement techniques have evolved over time and now include photographic, and more recently, automated disdrometer and laser measurement techniques. The review revealed that while advances in technology have allowed many of the deficiencies of early techniques to be eliminated, challenges still remain in the precise measurement of the size, shape, and velocity of raindrops and rainfall. The different measurement techniques were compared adapted to in...
Water, 2016
For over a century there have been many studies that describe the use of rain drop measurement te... more For over a century there have been many studies that describe the use of rain drop measurement techniques. Initial manual measurement methods evolved due to improved technology to include photographic and, more recently, automated disdrometer and laser measurement techniques. Despite these numerous studies, there have been few comparative reviews of the range of methodologies, and their relative performance. This review explores the raindrop measurement techniques available, and summarizes and classifies the techniques according to the method or principle involved. The requirements of a robust raindrop measurement technique are suggested, and these are reviewed against existing rain drop measurement techniques to provide a comparative guide to the use of the range of techniques available for any research study. This review revealed that while advances in technology have allowed many of the deficiencies of early techniques to be eliminated, challenges remain in relation to the precision of the measurement of the size, shape, and velocity of rain drops.
Demand for new construction methods are triggered due to post tsunami rehabilitations, recent lan... more Demand for new construction methods are triggered due to post tsunami rehabilitations, recent landslides, floods and present developments in the North-East etc. Structurally insulated panels (SIPs) are one such system, which expedite and ease the construction work. In Sri Lanka major cities are located along the coastal belt where corrosion is inevitable. Though corrosion is not an uncommon event, effect of corrosion on load carrying capacity of SIP panels is not well documented in published literature yet. Hence, present study focused on finding the effect of corrosion on load carrying capacity and to propose durability enhancement methods of SIPs. Corrosion-induced damage was simulated in the cementitious structurally insulated panels (CSIPs) by reducing the reinforcing steel volume. Experimental investigations were carried out for SIP panels where three were having GI meshes and the other three were with chicken meshes (40% reduced steel volume) as reinforcement. All panels were testedfor compressive strength after 28 days. Durability enhancement (delaying or preventing corrosion) of CSIPs was tested by casting four panels. One panel was kept as reference panel and other three were sprayed with 0.1M Nacl solution to accelerate corrosion. Among these three panels, one panel was applied with water proofing agent and other was coated with weather shield paint and another was left uncoated. These panels were tested for compression after three months of periodic wetting and drying with salt water. 27.4% reduction in load carrying capacity was observed with chicken mesh. Moreover load carrying capacity of CSIPs were enhanced by 17.5% with weather shield paint coated and by 38.8% with water proofing agent with reference to not treated-but periodically salt sprayed panel. In this paper, in addition to comparing the durability enhancement techniques, there costs were also compared before concluding the paper with recommendations
Gravity type retaining walls have been widely used to retain soil in Sri Lanka. However, it was r... more Gravity type retaining walls have been widely used to retain soil in Sri Lanka. However, it was reported that the performance of gravity type retaining walls during earthquake is poor. In view of the above, it was attempted in this study to develop a methodology to estimate the possible displacements of commonly found gravity retaining walls in Sri Lanka due to expected earthquakes. In addition, it was attempted to recommend an optimum shape for gravity retaining walls to minimize the possible displacements. This work was backed by Mononobe-Okabe theory and Newmark‟s sliding wedge analysis. Using Mononobe-Okabe analysis, threshold acceleration that would cause a relative displacement between retaining wall and soil, was found for different types of retaining walls. Using Newmark‟s method, an analytical model was developed to predict lateral displacements during seismic loadings. Then different acceleration-time histories of earthquakes, which are similar to those observed near Sri L...
Present study attempted to verify the feasibility of producing cement blocks by partially replaci... more Present study attempted to verify the feasibility of producing cement blocks by partially replacing fine aggregates with carbon black contaminated silica sand (CBCSS), which is a by-product of the tyre manufacturing process. In the present study performance tests such as compressive testing and flexural testing were conducted. In addition resistance against rain drops was measured and the quality of water, in case of inundation was also checked. As experimental investigations, eight individual black blocks were cast and tested for compressive strength and nine sample panels were made and tested for flexural and compressive strengths. In addition, pressurized drizzle test was conducted for individual blocks to study the erosion resistance characteristics against rain. Moreover, particularly in lower lands, during floods there is a room for these panels containing CBCSS being immersed under water for certain days. The present study accommodated the above through water quality test and...
There have been numerous successful soil erosion and infiltration studies using artificial rainfa... more There have been numerous successful soil erosion and infiltration studies using artificial rainfall simulation techniques. However, there appears to have only been a limited number of stormwater quality studies that have utilised these techniques successfully. To better understand the reasons for the low success rate in stormwater studies, a comprehensive literature review of previous studies using rainfall simulation techniques to replicate natural rainfall conditions was undertaken. The literature review was performed as part of an ongoing study to guide and direct the development of new rainfall simulator at the University of the Sunshine Coast in Australia. The review found that the characteristics of natural rainfall events are extremely difficult to replicate accurately in mobile rainfall simulator test rigs. The study results also suggest that the characteristics of natural rainfall events are not comprehensively understood, and that there is much scope for increased research...
This paper critically reviews the relevant published literature on rainfall simulators. This was ... more This paper critically reviews the relevant published literature on rainfall simulators. This was done to identify the most important design requirements for the fabrication of rainfall simulators, and to direct the development of a new rainfall simulator at the University of the Sunshine Coast in Australia. The paper also presents results of an experimental investigation into the spatial uniformity of naturally occurring rainfall distribution patterns. The review results suggest that the characteristics of natural rainfall events are not comprehensively understood, and that there is much scope for increased research knowledge in this area.
For over a century there have been many studies that describe the use of rain drop measurement te... more For over a century there have been many studies that describe the use of rain drop measurement techniques. Initial manual measurement methods evolved due to improved technology to include photographic and, more recently, automated disdrometer and laser measurement techniques. Despite these numerous studies, there have been few comparative reviews of the range of methodologies, and their relative performance. This review explores the raindrop measurement techniques available, and summarizes and classifies the techniques according to the method or principle involved. The requirements of a robust raindrop measurement technique are suggested, and these are reviewed against existing rain drop measurement techniques to provide a comparative guide to the use of the range of techniques available for any research study. This review revealed that while advances in technology have allowed many of the deficiencies of early techniques to be eliminated, challenges remain in relation to the precision of the measurement of the size, shape, and velocity of rain drops.
This paper critically reviews the relevant published literature on rainfall simulators. This was ... more This paper critically reviews the relevant published literature on rainfall simulators. This was done to identify the most important design requirements for the fabrication of rainfall simulators, and to direct the development of a new rainfall simulator at the University of the Sunshine Coast in Australia. The paper also presents results of an experimental investigation into the spatial uniformity of naturally occurring rainfall distribution patterns. The review results suggest that the characteristics of natural rainfall events are not comprehensively understood, and that there is much scope for increased research knowledge in this area.
It is in the last five years that the stakeholders of concrete paving blocks (CPBs) are awakening... more It is in the last five years that the stakeholders of concrete paving blocks (CPBs) are awakening to engineer the CPBs in Sri Lanka. Although large scale production of CPBs has already flourished in Sri Lanka, their adherence with stringent standards (both Sri Lankan and International) remains dubious. This reluctance to meet the performance and durability criteria according to codes of practices, curtails the life span of concrete block paved roads to a greater extent.
It is in the last five years that the stakeholders of concrete paving blocks (CPBs) are awakening... more It is in the last five years that the stakeholders of concrete paving blocks (CPBs) are awakening to engineer the CPBs in Sri Lanka. Although large scale production of CPBs has already flourished in Sri Lanka, their adherence with stringent standards (both Sri Lankan and International) remains dubious. This reluctance to meet the performance and durability criteria according to codes of practices, curtails the life span of concrete block paved roads to a greater extent. The scope of the present paper is limited to verifying whether the local concrete paving blocks are made on par with international standards. Sample blocks were obtained from local CPB manufacturers and investigated. Though these blocks met the criteria in Sri Lankan Standard for CPBs for strength classes 2, 3, 4 roads, none of them met the compressive strength criteria for strength class 1 roads. Besides, tensile strength requirement specified in the BS EN 1338: 2003 was met by none of the blocks tested. Since, Sri Lankan Standard is planned to incorporate splitting tensile strength as the dominant measure to assess paving blocks in the near future, this study also attempted to identify a mix proportion to meet the splitting tensile strength requirement specified in BS EN 1338: 2003. When CPBs were casted using CPB making machine, an intolerable strength deviation was observed. A series of tests were conducted to explore the reasons for this. The outcome of which would help the small scale manufacturers to keep strength variations within a tolerable range, when they are using CPB making machines.
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Papers by Gopinath Kathiravelu