高铁大跨斜拉桥主梁CPⅢ点实时高程预测方法研究及应用

Research and Application of Real-time Elevation Prediction Method of CPⅢPoints in Main Girder of High-speed Railway Long-span Cable-stayed Bridge

针对高铁大跨斜拉桥主梁上CPⅢ点高程的多值性问题,结合昌赣高铁赣江特大桥工程案例,提出一种大跨斜拉桥主梁上CPⅢ点实时高程预测方法。首先,通过最小二乘线性回归法确定主梁上各CPⅢ点对高程变化量与主跨跨中CPⅢ点对高程变化量之间的数学关系式;然后,采用主成分回归分析法,建立各类传感器读数变化量与主跨跨中CPⅢ点对高程变化量之间的多元线性回归方程,从而得到主梁上所有CPⅢ点的实时高程预测模型。采用该预测方法能够保证赣江特大桥主桥上CPⅢ点高程设站精度达到0.7 mm,满足无砟轨道施工精调的精度要求。该方法目前已成功指导了赣江特大桥主梁上无砟轨道的施工精调工作,保证了昌赣高铁顺利建成通车。

In view of the multi-value problem of the elevation of CPⅢpoints on the main beam of the high-span long-span cable-stayed bridge,this paper proposes a real-time elevation prediction method of the CPⅢpoints on the main beam of the long-span cable-stayed bridge based on the Ganjiang extra large bridge project of NanChang-Ganzhou High-speed Railway.The regression analysis method is used to determine the mathematical relationship between the CPⅢpoint-to-elevation variation of the main beam and the CPⅢpoint-to-elevation variation of the main span.Then the principle component regression analysis method is employed to extract the main components that affect the changes of the elevation of CPⅢpoints on the mid-span.On this basis,a multiple linear regression is established between the changes in the reading of various sensors and the changes of the elevation of CPⅢpoints on the main beam.Meanwhile,the real-time elevation prediction model for all CPⅢpoints on the main beam is obtained.It is concluded that this prediction method can ensure 0.7 mm elevation accuracy of CPⅢpoints on the main bridge of the Ganjiang River Bridge,which meets the precision requirements of ballastless track construction fine tuning.So far,this method has successfully guided the fine tuning of the ballastless track construction of the main girder of Ganjiang Extra Large Bridge,and guaranteed the smooth completion of the NanChang-Ganzhou High-speed Railway.