Study On Pier Structure And Stability For The Super High-pier Continuous Rigid Frame Bridges

Transportation infrastructure runs into an unprecedented opportunity with theimplementation of supremacy development of the West Region. The PC continuousrigid frame bridge becomes the mountainous structure form via valleys and rivers. Formore than one hundred meters high piers of long span continuous rigid frame Bridges,the piers’s structural form directly influence the mechanical behavior of the superstructure, and its state stability also is particularly important at the construction stage.Therefore, the study on pier structure and stability for the super high-pier continuousrigid frame bridges is very necessary. This paper take the design and construction keytechnology research for the super high-pier continuous rigid frame bridge of HeZhangwhich is the science and technology project in GuiZhou Provincial Department ofTransportation (2010-122-017) as the subject source, research the piers structure andstability, including the following contents:As the foundation of structural stability theory, this paper established the model of195meters high variable cross-section pier belongs to HeZhang bridge,155meters highcombination pier form of double thin-wall piers-single pier belongs to TianQiao bridgeand195meters high concrete filled steel tube pier using the universal finite elementprogram of ANSYS beam element and shell element. At the longest cantilevered stage, itanalyzed the double nonlinear stability about three types of piers under the different loadcondition combination. Through the stability coefficient curve, evaluated initial defects,bridge structure and material strength to the influence of the piers stability, also analyzedthe relationship about bridge instability modes and anti-push rigidity, got the beststructural proportion point of combination pier which was that: when two parts piers asan independent structure, the anti-push rigidity on either side of the pier is equal.According to the material mechanics of inertia cross-section bending calculationprinciple, this paper deduced the cross-section bending inertia formula of variablecross-section pier through the cross-section structural parameters. This formula can moreaccurate reflects the bending strength of all cross section compared to the formula whichis simulated by using the general interpolation function.Based on "conjugate beam method" theory, the paper derived the anti-push rigidityformula of variable cross-section pier and combination pier using variable cross-section bridge pier cross-section bending inertia formula. Combined with different structuraltypes of the bridge structure, the calculation error is in engineering tolerance range.Moreover, according to the anti-push rigidity are equal, this paper got the equivalentinertia of variable cross-section of the pier; the results meet well with the valueaccording to Euler formula.