斜拉桥索塔锚固区双层U形预应力束的张拉控制试验研究

Experimental Study on Tension Control of Double U Tendons in Anchorage Zone of Cable-stayed Bridge Pylon

通过模型试验和有限元分析,确定了双层U形预应力筋的张拉控制程序。比较张拉后模型内部传感器测试的预应力效应和采用空间有限元分析的应力结果,可以检验U形预应力筋张拉后是否达到设计要求的预应力状态,从而得出张拉程序的可靠性。结果表明:正确的张拉操作程序,不仅能将实测张拉伸长值与理论伸长值的偏差控制在规范之内,而且能使得张拉后的预应力效应达到设计的要求。

The procedure for tension control of double U tendons in the cable-stayed bridge pylon is brought forward through the comparison of model experiment and finite element method. The prestressed effect tested by the sensor in the model was compared with that of calculated by the finite element method, which can be used to find out if the stress state in the anchorage zone attained the expected design requirement after tendons stressed. Consequently, the reliability of procedure could be verified. The result indicates that the proper tension procedure not only can emure the deviation of theoretical and measured elongation within the norm, but also make the stress distribution in the anchorage zone meet the design requirements.