| In recent years,with the progress of science and technology,the modern cable-stayed bridges have been developed rapidly.All kinds of uncertainties in construction have been arisen due to the increase of the span length.The engineering construction of cable-stayed bridges is faced to high risk,so we must take active measures to cope with it.Taking the Nancang Cable-Stayed Bridge in Tianjing as background,starting from actual bridge engineering,this paper is mainly to study on the structure simulation calculation and risk assessment in construction.In this paper,the basic theory of risk assessment is presented.The basic theory of calculation and analysis of cable-stayed bridges is studied.These studies lay a foundation for the simulation calculation and risk assessment in construction of cable-stayed bridges.Then the author uses the large universal finite element software Midas/Civil to establish simulation model of Nancang Cable-Stayed Bridge. Completion stage and each construction stage are calculated and analyzed in detail. Analytic hierarchy process is used to qualitatively identify the construction risk of Nancang Cable-Stayed Bridge.The main risk modes and main risk factors influencing the construction safety are identified.A Computer Language Fortran based on Monte-Carlo method is used to quantitatively estimate construction risk probability. According to acceptable failure probability,construction risk is simply evaluated.Risk control measures for the construction of Nancang Cable-Stayed Bridge are proposed.Study results show that strength failure of main beam is the most important construction risk mode,and cable forces,section size,elastic modulus and material unit weight are the most important construction risk factors.The structure stress in maximum cantilever,closure and completion states is relatively large,so the risk probability may exceed the acceptable range.Some effective measures must be taken to control risk.
|
PDF Full Text Request