Static Reliability Analysis Of Single Cable Plane Cable Stayed Bridge Base On Kriging Method

Single cable plane cable-stayed bridge is widely used in the highway bridge, because ofits economy and with beautiful open inspect sense. Nowadays, the design and construction ofSingle cable plane cable-stayed bridge are basically adopted the deterministic method, whichis not accordance with the structural behavior. The responses of bridge under environmentaleffects are essentially affected by many random factors such as external loadings, materialparameters and geometry factors and so on. As a highly indeterminate and flexible structure,the structural responses of long-span cable-stayed bridges are complex. Analysis methodsbase on probability theory is the hot spot to study the reliability of cable-stayed bridge, andit’s the development trend of complex bridges. This paper combined Kriging method withreliability calculation method, compiled the MATLAB program of improved response surfacebased on Kriging method. And established the static reliability calculation model of singlecable plane cable-stayed bridge, get the following conclusion:(1) Response surface equation is constructed base on Kriging method, which is conbinedwith MC method to calculate the reliability index. The response of each point is forecast bymeans of Kriging, and significant contribution points were selected to update the responsesurface equation to improve the precision. Numerical examples were carried, the resultsindicated that this method is correct and effective.(2) The improved reliability analysis method based on Kriging method is adopt tocalculate the deflection reliability of main girder of Daxie Second Bridge under serviceabilitylimit-state. The results indicated that this bridge has high reliability, the geometric non-lineareffects cannot be ignored. Besides, when the main span was fully occupied with traffic loads,the reliability index of maximum displacement of main girder was significantly lower thanthat the whole bridge was fully occupied with traffic loads.(3) Under the ultimate limit states without wind load, the reliability indexes will be largerthan actual value if the axial force is ignore. And compare the value when the main span wasfully occupied with traffic loads with that the whole bridge was fully occupied with trafficloads. The results indicate that, the prior load case is insecurity than the posterior.(4) Under the ultimate limit states,the bridge has high reliability with strong wind load.And the pillar section plays the control effect. When the wind velocity is small, the live loadarrangement has large effect on reliability of pylon section, when the wind velocity is large,wind velocity has greater effection than live load arrangement. Besides, the attack angle hassignificant influence for reliability analysis.