中小跨径悬索桥主缆线形简化计算方法研究

悬索桥主缆线形的计算在悬索桥设计与施工控制中具有十分重要的意义,针对精确的计算理论在有限元迭代计算中难以收敛和耗费大量计算时间的缺点,考虑到中小跨径悬索桥的小垂度主缆的特点,给出不同重力刚度下索单元与梁单元相互转化的理论依据,从理论上保证了在主缆线形计算中采用梁单元模拟主缆的可行性;介绍了梁单元几何非线性计算的基本原理与基本方法,并通过固镇县浍河二桥主缆线形计算验证了方法的可靠性。实际计算结果表明,对于中小跨径悬索桥主缆线形所采用的这种简化计算方法,具有计算速度快、算法稳定、易于收敛的优点。

STUDY ON SIMPLIFIED CALCULATING METHOD OF MAIN CABLE CURVE OF MEDIUM SPAN SUSPENSION BRIDGE

The calculation for the main cable curve during the design and construction control of suspension bridge is very important. Contrary to the fault of precise calculation theory which is difficult to converge in iteration of finite element and spends a lot of calculation time,taking account of the particularity of small sag on main cable of medium span suspension bridge,the theoretical basis on the transformation between beam element and cable element under different gravity stiffness was proposed. The feasibility of using beam element to simulate cable for calculating the curve of suspension was theoretically ensured. The basic principle and method of geometric nonlinear calculation for beam element was introduced,and the reliability of this method in this paper was proved by calculating the cable curve of the second bridge on Huihe River in Guzhen County. The actual result of the calculation indicated the advantage of rapid computing speed,stable calculating steps and easily converging for the simplified calculating method of cable curve of medium span suspension bridge.