上承式拉索拱桥成桥索力优化研究

Optimization of Cable Tensions of Finished Deck Type Arch Bridges With Diagonal Cables

针对影响矩阵法和单位荷载法建立索力优化计算的数学模型,未考虑施调索力间相互作用的不足,提出了双影响矩阵法,并对其进行理论推导;该方法以拱肋弯曲应变能最小为优化目标建立数学模型,计算无迭代过程,可直接得到优化索力的精确值;并以1座200 m跨上承式拉索组合拱桥为例,采用3种不同的方法进行索力优化计算.结果表明:双影响矩阵法计算速度快、精度高.

Mathematical model is usually established for optimization of cable tension by influence matrix method or unit load method now, without regard to mutual effect between adjusted cable-forces. Aimed at their shortcomings, double influence matrix method for optimization of cable tension is put forward and theoretical derivation is made in this paper. Minimum bending strain energy of arch ribs is considered as optimum object by means of two influence matrixes in this method. Without iterative calculation, exact cable forces could be obtained using this method immediately. Finally, taking a deck type arch bridge with diagonal cable as an example, optimization calculation of cable tension is conducted separately using three different kinds of method in this paper. The research result shows that double influence matrix method has the characteristic of fast operating speed and high precision.