基于二级横张法的PC桥梁高强钢丝有效张拉力测试

Test of Effective Tension of High-strength Wire in PC Bridge Based on Transverse Tensioning Method

为了检测PC桥梁高强钢丝的有效张拉力值,采用自主研发的预应力钢索张力测试仪(LCZL-50),在WED系列电子万能试验机上进行了试验测试研究。首先通过试验机将高强钢丝张拉到不同预应力值,应用二级横张原理对高强钢丝进行有效张拉力测试,然后基于最小二乘法对试验测试数据进行分析处理,通过回归计算得出高强钢丝的有效张拉力。将该方法用于实桥测试和计算,结果显示,?5 mm高强钢丝在较小横张力作用下,横张力与横张位移成线性变化,且满足小变形条件,其有效张拉力实测值与理论值的误差小于5%,表明该方法的测试精度满足实际工程需要,可为PC桥梁的维护、加固或改造提供技术依据。

To test the effective tension of high-strength steel wire of PC bridge, experiments were carried out on a WED electronic universal testing machine using a tensioned tension tester （LCZL-50） that is developed independently. First, the high-strength steel wire was stretched to different tension values using a testing machine, then the effective tension of it was tested by transverse tensioning method, and the experimental data were analyzed based on the least squares method. The above method was used in practical bridge test and calculation. The results of comparative analysis of the theoretical value and measured value of PC bridge show that when the 65mm high-strength steel wire was under relatively small transverse tension, the variation of transverse tension and transverse displacement had a linear relationship, and conditions of small deformation were satisfied. The error between the measured value and theoretical value was smaller than 5%, indicating the test precision of this method meets the demands for practical engineering, and may provide technical basis for the maintenance, strengthening or modification of PC bridges.