Analysis Of Continuous Beam Construction Risk Based On Structual System Reliability

The force of the long span prestressed reinforced concrete continuous beam with v supports is more complex,and the construction process is also more complicated,the v leg structure whether construction process is smoothly is the key to the bridge.and also is the key of continuous beam construction risk analysis.This paper aim at studying on the long span continuous girder with v supports.Basing on the Guilin longmen bridge and studying on risk during the bridge construction about this bridge style.First,choosing the fuzzy analytic hierarchy process identify the risk about the continuous beam with v supports.and preparing the corresponding calculation program use the MATLAB software.And also reducing the calculation process about the risk identification.The basic method for reliability analysis not be solved the High-order nonlinear implicit function such as the first-order second-moment method and the second-order second-moment method.So proposing an integrated approach based on the uniform design method-the finite element-the genetic algorithm-the BP neural network-second-the order second-moment method.And preparing the corresponding calculation program use the MATLAB and MIDAS software.It can solves the Risk Probability about the continuous beam with v supports conveniently.Then,establishing the mathematical model about the risk loss in the construction period of the continuous beam with v supports.It can be used to solving the risk probability of the continuous beam with v supports conveniently.Based on the existing risk assessment and decision-making outcomes,and combined with China's national conditions and economic development,establishing the risk acceptance criteria in construction about the continuous beam with v supports.So can make a quantitative evaluation about this bridge style.At last,Making the risk assessment about the flexural failure of the prestressed box beam of the bridge superstructure in the construction period in the engineering background of the longmen bridge.According to the risk acceptance criteria established in this paper,determining that the risk that the main girder of the longmen bridge in the external condition such as predestinate constructing environment and the flow time is acceptable.Simultaneously,according to the evaluation results,suggesting the decision-maker and managers of risk to take measures improve security of the longmen bridge in the construction period.and should pay attention to the more risk factor such as crane girder,section modulus of the main girder,sectional inertia moment,section size,stretching control stress of prestressed tendons in the construction period.