Available online at: http://www.ijmtst.com/vol3issue10.html
International Journal for Modern Trends in Science and Technology ISSN: 2455-3778 :: Volume: 03, Issue No: 10, October 2017
Effectiveness of using Geotextiles in Flexible Pavements and Life-Cycle Cost Analysis Yasodhara Vegesana1 | P.S.Nadiu2 | PMS Satish Kumar2 1PG
Scholar, Department of Civil Engineering, Sanketika Institute of Technology and Management , Visakhapatnam, Andhra Pradesh, India. 2Assistant Professor, Department of Civil Engineering, Sanketika Institute of Technology and Management, Visakhapatnam, Andhra Pradesh, India. 3Head of the Department, Department of Civil Engineering, Sanketika Institute of Technology and Management, Visakhapatnam, Andhra Pradesh, India. To Cite this Article Yasodhara Vegesana, P.S.Nadiu and PMS Satish Kumar, “Effectiveness of using Geotextiles in Flexible Pavements and Life-Cycle Cost Analysis”, International Journal for Modern Trends in Science and Technology, Vol. 03, Issue 10, October 2017, pp: 60-71.
ABSTRACT Using geotextiles in between the pavement layers (generally at the interface of subgrade and sub-base) to stabilize weak subgrades has been a well-accepted practice over the past few decades. However, from an economical point of view, a complete life cycle cost analysis (LCCA), which includes not only costs to agencies but also costs to users, is urgently needed to assess the benefits of using geotextile in flexible pavement. Two comparative methods were used to quantify the improvements of using geotextiles in pavements. One is Life Cycle Cost Analysis (LCCA) and the other is Economic Analysis. LCCA is a tool which is generally used after the agency has taken decision to implement the project and seeking to determine the most cost-effective means to accomplish the project’s objectives. Unlike LCCA, EA considers the benefits of an improvement as well as its costs and therefore can be used to compare design alternatives that do not yield identical benefits, as well as to compare projects that accomplish different objectives. In this study, a comprehensive life cycle cost analysis framework was developed and used to quantify the benefits of using geotextile at subgrade level in economic terms. For this, a case study of Dhanbad city in Jharkhand was selected where six roads of different hierarchy are being developed with World Bank funding. As per the soil and material investigations, the CBR value of existing subgrade soil was 4%. However, after using geotextile at subgrade level the equivalent strength was found to be around 8%. Forming both as two alternative case scenarios, both Economic Analysis (using HDM - IV developed by the World Bank) and Life Cycle Cost Analysis was conducted. The study concludes that geotextile layer plays a key role in increasing the pavement CBR value from 4% to 8%. Additionally, it also results in economic benefits as increase of average 1%-1.5% in EIRR value can be noted as compared to the pavement without geotextile layer. The results of LCCA shows that initial construction cost of the alternative with 4% CBR (without geotextile layer) as well as life cycle cost is more than the corresponding cost for the second alternative with 8% CBR (with geotextile layer).Hence, the second alternative (CBR 8% - with geotextile layer) is recommended based on both Economic Analysis as well as LCCA. Hence, for an optimum road flexible pavement design with geotextile incorporated in the system, a life cycle cost analysis that includes user cost as well as economic analysis must be performed. Keywords: HDM (Highway Development and Maintenance), CBR, Geotextiles, LCCA (Life Cycle Cost Analysis).
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