斜拉桥索塔锚固区预应力摩阻损失试验研究

为确定结构中的有效预应力水平,对巴东长江大桥索塔锚固区结构中具有多种线形的预应力筋孔道摩阻损失进行了试验研究,介绍了测试原理、方法以及获得的试验成果,并对结果进行了分析.试验获得了不同线形预应力筋在各分级张拉荷载作用下的预应力损失值;采用最小二乘原理,根据测试数据进行回归计算得到了摩阻系数和孔道偏差系数;与中国、美国各相关规范进行了对比,试验发现测试值与规范参考值有一定偏差.对于类似重要工程结构,建议宜采用试验测试方法确定孔道摩阻损失水平.

Study of Prestressing Friction Loss Test for the Anchorage Zone of a Cable-Stayed Bridge

To determine the effect prestressing level,the loss of tube frictional resistance of curved prestressed tendons with varied configurations was tested and studied for the anchorage zone of Badong Changjiang Highway Bridge.The principle,procedure and achievements were introduced and the experimental results were analyzed.The loss value of tendons under each load level was obtained in the test.Based on least square principle,the curvature friction coefficient and wobble friction coefficient were worked out according to the test data.The curvature friction coefficient agreed with the codes while the wobble friction coefficient was lower than the reference value given by the codes.For such important engineering structure,it is suggested that test method should be adopted to determine the level of the friction loss.