Risk Assessment Method Of Long-span Self-anchored Suspension Bridge During Construction Stages

Recently, the long-span self-anchored suspension bridge is widely used in our country. The structure which is composed by main cable, main beam, main tower and sling is beautiful and unique and loved by most bridge designers. But the bridge is complicated in structure, difficult in structure design, and immature in structure calculation theory, and as a consequence of lots of high altitude work and various uncertain factors’ influence, the construction process is difficult and prone to accidents. Therefore, in order to reduce accidents and improve the bridge quality, it is necessary to conduct risk assessment for long-span self-anchored suspension bridge. Based on the structural features of long-span self-anchored suspension bridge, analysis on risk assessment methods of the construction is completed, and the details are as follows:① The paper focuses on the construction risk assessment of long-span self-anchored suspension bridge, introduces its current research status, and describes the basic concepts of risk. It defines the construction risk of long-span self-anchored suspension bridge, and describes the general flows of risk assessment.② Combined with the character of long-span self-anchored suspension bridge, we divide the bridge into main tower, main beam and cable by analytic hierarchy process in risk identification in order to fully distinguish risk in the course of construction. then identify main risk factor and its relative weight, and build a bridge construction risk factor sorted list.③In the construction risk evaluation, the paper takes the aspect of risk probability and risk effect into consideration, uses the fuzzy comprehensive evaluation(FCE) to determine the risk level, determines an acceptable level of risk by means of ALARP criterion, and finally sets up a "long-span self-anchored suspension bridge construction risk assessment system ".④ Based on the Songyuan Tianhe bridge, this paper uses the "long-span self-anchored suspension bridge construction risk assessment system" to carry out the risk assessments of this bridge, combines expert investigation method with fuzzy comprehensive evaluation method to evaluate construction risk, and determines the level of overall construction risk and acceptable level of risk, then puts forward some concrete countermeasures for some influential risk factors according to acceptable level of risk.