Summary: | 碩士 === 國立成功大學 === 土木工程學系 === 102 === In Taiwan, due to the rapid increased highway network in the past ten years as well as aging of the highway infrastructure, Taiwan Area National Freeway Bureau (TANFB) has encountered great challenge to maintain their highway network in good condition. The major challenge for pavement engineers is to maintain good condition of roadway with least costs. In order to estimate maintenance cost for whole highway network, it is important to know when and how much percent of pavement network fails in the future. In this study, two reliability analysis approaches (failure-time analysis as well as degradation analysis) were performed to estimate the network level pavement service life based on international roughness index (IRI) data collected from the outer lane of Taiwan’s national freeway network during 2006 to 2010. The pavement maintenance threshold of 3, 3.5, and 4 m/km and failure probability 25 percent were used to estimate the pavement service life for pavements in the north, central and south district of national freeway system. The results of failure-time analysis shown that the predicted pavement service life for the north, central and south district of southbound freeway one are 4.9, 4.6 and 1.6 years; of the northbound freeway one are 2.5, 4.8 and 0.8 years; of the southbound freeway three are 2.6, 2.4 and 1.6 years, and of the northbound freeway three are 2.4, 2.6 and 2.9 years. For the degradation analysis, the estimated pavement service life of north, central and south district of freeway one southbound are 2.6, 3.4 and 1.6 years; of freeway one northbound are 2.5, 3.8 and 1.2 years; of freeway three southbound are 3.4, 4.3 and 1.3 years; and of freeway three northbound are 3.2, 3.4 and 2.4 years. In general, both approaches estimate pavement service life of 2 to 5 years that is similar to the maintenance frequency currently adopted by the expert engineers in the TANFB.
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