钢管混凝土系杆拱桥稳定性分析

基于线性和非线性稳定理论对某钢管混凝土系杆拱桥进行稳定性分析。由数值模拟分析可知，考虑材料与几何双重非线性时稳定性系数计算结果比仅考虑桥梁的几何非线性时小50％。改变桥梁的横撑形式、矢跨比和内倾角并进行计算分析，结果表明，随着横撑数量的增加，桥梁稳定性系数呈线性增长趋势，且K字、X字横撑的设置对桥梁稳定性系数提高更有利；矢跨比从1／8变化到1／3时，桥梁稳定性系数先增加后减小，且此变化范围内，最安全矢跨比为1／5；拱的内倾角从0°变化到8°时，桥梁稳定系数呈抛物线变化趋势，内倾角为6°时稳定性系数最大。

Analysis for Stability of Concrete Filled Steel Tube Tied-arch Bridge

This paper analyzes stability of some concrete filled steel tube tied-arch bridge based on linear and nonlinear stability theories. As known from numerical simulation analysis, the calculated result of stability coefficient in consideration of both material and geometric nonlinearities is less than that only in consideration of geometric nonlinearity of bridge by 50%. The paper conducts calculation and analysis by changing cross arm forms, rise-span ratio and leaning angle, and the result indicates that the stability coefficient of bridge presents the trend of linear increase with increase of cross arms, and the setup of K and X-shaped cross arms is more favorable for improvement of stability coefficient of bridge; as the risespan ratio changes from 1/8 to 1/3, the stability coefficient of bridge decreases after increase, and within this range of variation the safest rise-span ratio is 1/5 ; as the leaning angle of arch changes from 0° to 8°, the stability coefficient of bridge presents the trend of parabolic variation, and is maximal when the leaning angle is 6°.