三次样条插值确定拱桥合理拱轴线的方法探讨

探讨了在拱桥设计中利用给定的设计初始条件，计算出合理拱轴线的特征点坐标，应用三次样条插值方法拟合出拱桥设计拱轴线，算例表明三次样条插值方法确定的拱轴线能较精确地逼近拱桥的恒载压力线，从而有效地减少拱桥主拱圈的弯距及剪力。

A Study of Method of Determining Rational Arch Axis Using Three Order Splin Interpolation

Broken line,higher parabola curve and catenary are usually used as the arch axis of long and middle span arch bridge,because these line styles utilize relatively fewer information that the design of arch bridge can offer,so they have obvious bias with the compress line of dead load of arch bridge,which leads to unfavorable momentum and shear force in the structure.This paper studies the method determining the arch axis which utilizes the initial condition of the design to calculate the coordlinates of the compress line of dead load in some points of arch bridge by applying three order spline interpolation function to approach the compress line of dead load gradually at any given precision.An example illustrates that the method has practical value in the design of arch bridge.