Dissertation > Excellent graduate degree dissertation topics show

Time-dependent Reliability Analysis of Existing Double-curvature Bridge Strengthened with Augment Section Method

Author: WangZuo
Tutor: KangJunTao
School: Wuhan University of Technology
Course: Bridge and Tunnel Engineering
Keywords: time-dependent strengthening existing double-curvature bridge reliability
CLC: U445.72
Type: Master's thesis
Year: 2011
Downloads: 84
Quote: 0
Read: Download Dissertation

Abstract

Bridges are designed to function over long periods of time. The incidence of structural deterioration increases with bridge age due to corrosion, fatigue and other forms of material property deterioration. During this same period vehicle, loads and legal load limits have been steadily increasing. So existing bridges experience changes in both resistance and applied loads which are time variant. Structural elements composed of concrete and reinforcing steel are frequently determined inadequate to sustain current or new load levels imposed on bridges. There is an increasing need, and a great challenge to repair and update the transportation infrastructure of the world. Recently, a common strengthened method is to use augment section method which can increase load capacity effectively.Using the ex-scholars’ research result for reference, this paper has considered all the affecting factors of resisting force. Based on these factors, the time-dependent models of concrete strength, steel bar strength and sectional area, felt retrogression for concrete and steel bar have been built. The emphases is the changing of steel bar sectional area, taking corrosion of steel bar and factor of fatigue dandification into consideration to build steel bar sectional area time-variation model.Loading is one of the main loading of bridge construction, including statistic loading and vehicle loading, considered as random variable. According to abroad investigation information, introduces random variable model of statistic loading and vehicle loading separately as .per domestic. Statistic loading is normal distribution and vehicle loading is extreme-value I distribution.Based on the models of time-dependent resisting and vehicle loading, this paper has induced the limit states equation of bearing ability of the existing structure, and using the time-dependent reliability analysis double-curvature bridge strengthened. This paper has used finite element programming Midas/Civil to analysis two states of before reinforcement and after reinforcement. To contrast with two states of force, the results have showed that the structure damage is due to large moment, especially the arch feet has endured the largest moment. So the arch feet have been chosen to as the controlled section. Then, the reliability indexes have been calculated. According to these indexes, the working states of the structure have been estimated.

Related Dissertations

CLC: > Transportation > Road transport > Bridges and Culverts > Bridge Construction > Bridge maintenance, repair and remediation > Bridge strengthening
© 2012 www.DissertationTopic.Net Mobile