a case study of Bhutan Kunzang Wangdi creator Chen, Jian-Shiuh Chairperson Morisugi, Hisa Examination committee Bergado, Dennes T. Examination Committee Bhutan-Netherlands Bilateral Sustainable Development Project Scholarship donor text th Bangkok Asian Institute of Technology 1996 monographic eng

print

93 leaves Most of Bhutan's road network comprising of more than 3000 km of highways, district and feeder roads is deteriorating at a much faster pace than it can be repaired. Lack of experience in road maintenance and shortage of funds further contributes to increased deterioration. The East-West Highway in particular has suffered considerable deterioration since its construction in the early eighties. Indeed, the tasks of road construction and maintenance are difficult owing to Bhutan's rugged mountainous terrain. At present maintenance needs are decided largely on the basis of past experience rather than on a systematic needs appraisal. The lack of a rational system for pavement evaluation has made PWD rely heavily on past experiences in deciding the maintenance needs. This study presents a method for evaluation of pavement condition based on Pavement Condition Index procedure with particular reference to the maintenance of the East-West Highway. Detailed pavement distress data on the highway stretch between Semtokha to Nobding covering a distance of 95 Km were collected using visual method. For the purpose of analyses this highway section was grouped into two categories depending on the existing surface types. The first group contained 82 pavement sections with premix surface dressing application and the second group comprised of 13 sections with surface dressing application. The pavement condition index (PCI) for each section was determined using the "deduct value" approach. The deduct value represents the amount of deterioration suffered by each designated pavement section. Regression analyses were conducted to establish the pavement deterioration parameters for premix surfacing and surface dressing applications. Adopting the PCI terminal value of 60 as the service life the service life of the premix surface application was found to be 8 years whereas that for surface treatment application was about 6 years. The annual maintenance cost for premix surface pavement was found to be lower than that for surface treatment pavement, implying that in the long run premix surface application is cheaper. A matrix of maintenance costs for various PCI ranges was developed from the maintenance unit costs and the surface density matrix. A fiercest of future maintenance funds requirement was made for a five year planning period (1996-2000) by predicting the pavement condition index in the succeeding years of the planning horizon. An attempt was made to compare the cracking predicted by the PCI method and the cracking progression simulated by HDM-111. The cracking progression simulated by HOM-III was found to be significantly higher than that predicted by the PCI method. However this is a subject of further research. A thesis submitted in partial fulfillment of the requirement for the Degree of Master of Engineering, School of Civil Engineering Thesis (M.Eng.) - Asian Institute of Technology, 1996 Roads Bhutan Maintenance and repair Asian Institute of Technology. http://203.159.5.9/ait-thesis/detail.php?q=B15009 http://203.159.5.9/ait-thesis/detail.php?q=B15009 180698 20260818153916.0