全数据分析方法在预应力智能张拉中的应用

Application of Full Data Analysis Method in Prestressed Intelligent Tensioning

为充分利用智能张拉系统在张拉过程中采集的大量荷载及位移数据,以某高架桥为依托工程,以湖南联智LZ59N10型智能张拉系统的张拉数据为分析及验算数据,通过分析数据库文档数据转换处理,提出一种针对智能张拉过程数据的全数据分析方法。通过Excel文档绘制"荷载-位移"曲线,根据曲线的波动状态判断预应力束张拉过程的稳定性。若曲线较平顺、无过多锯齿状或其他不规则形状,说明张拉过程较稳定;若曲线不平顺、波动频繁或波动幅度大,则说明张拉过程不稳定。通过主观判断的"拐点"观测法、数据拟合软件最小二乘法,分别分析"荷载-位移"曲线由弧线转变为直线的"拐点",以此选取初始张拉力百分率。两种分析方法对比结果表明:数据拟合法分析得到的初始张拉力百分率最大,与实际情况接近,较为合理;用"拐点"观测法时,通过选取曲线逐渐变成直线位置的荷载值计算得到张拉力百分率,并适当提高2%~3%作为初始张拉力百分率。

To make full use of massive load and displacement data collected by an intelligent tensioning system in the tensioning process,a full-data analysis method aiming at tensioning data was proposed.The tensioning data collected by the Hunan Lianzhi LZ59 N10 intelligent tensioning system from a viaduct construction project were used as the base data,and then they were transformed and further analyzed.Specifically,the"load-displacement"curve was plotted by Excel,and the stability of the prestressing tendon tensioning process was determined according to the state of curve fluctuation.The tensioning process would be considered relatively stable if the curve is smooth without too many zigzags or other irregular shapes.However,an unsmooth curve with frequent or violent fluctuations would be considered an unstable tensioning process.The"turning point"between a curve line and a straight line from the"load-displacement"curve was respectively analyzed by the"turning point"observation method and data fitting method,thus the initial tension percentage could be selected.The results from the two analysis methods show that the initial tension percentage obtained by the data fitting analysis method is larger,which is more reasonable as it is closer to the situation onsite.However,the initial tension percentage is calculated by the load value at the"turning point"using the inflection point observation method should be raised by 2%to 3%for use.