某斜拉桥桥塔锚固区预应力筋优化研究

对某斜拉桥桥塔锚固区布置的双层环向预应力筋进行优化研究。将单位环向预应力筋对锚固区的预应力效应和正常工作拉索荷载对锚固区的索力效应分别单独进行考虑,然后采用线性叠加,得出了两者在锚固区的效应。通过考虑各种约束函数,并结合预应力筋数量最小这一目标函数,对某斜拉桥桥塔锚固区现有的环向预应力筋布置方式进行优化研究。优化研究表明:桥塔锚固区仅仅采用环向预应力筋布置时,长短边的应力和抗裂安全系数都不可能均匀;另外,预应力筋布置在锚固区偏外侧的位置时,所需预应力筋数量最少。

Study on Optimal Layout of Tendons in one Cable-Stayed Bridge Pylon

The ring tendon in anchorage zone of one cable-stayed bridge pylon was optimized in this paper.The effect of single strand and the designed cable force in the anchorage zone were analysised respectively.Through the linear superposition principle,the synthesis effect of them was attained.Combined with all kinds of constraint functions and the object function,which the number of the tendon was the lowest,the existing layout of U tendon in the anchorage zone of the cable-stayed bridge pylon was optimized.The result indicates that the stresses and the anti-cracking coefficients are not unanimous if there are only ring tendons in the anchorage zone.Moreover,the number of the required tendons is the lowest when they are placed partial to the outward anchorage zone.