采用钢内导管的斜拉桥索导管精确定位技术研究

Study of Accurate Positioning Technique for Stay Cable Guide Tubes of Cable-Stayed Bridge Using Internal Steel Guide Tubes

为提高斜拉桥索导管空间定位的精度,进一步推动测量定位技术的实用化,对采用钢内导管装置的斜拉桥索导管精确定位技术进行研究。钢内导管是由一根半圆柱体形状的细长轴(中心线处开有微小V形槽)相连双半圆法兰盘的一种装置,其中一端与半圆法兰盘平齐,另一端穿过半圆法兰盘。斜拉桥索导管定位时,在初步定位的基础上,将钢内导管穿入索导管中,利用钢内导管将出塔点坐标和理论锚点坐标由虚点转化为实点,对索导管进行直接精确复测定位,再利用两坐标点所在空间直线方程对实测点进行判别。将该技术应用于台州市椒江二桥上,实践结果表明该技术能简单快速地实现斜拉桥塔端索导管的精确定位,精度能达到5mm以内。

To improve the spatial positioning accuracy of stay cable guide tubes of cable-stayed bridge and further promote the actual implementation of surveying and positioning technique,the accurate positioning technique for stay cable guide tubes of cable-stayed bridge using internal steel guide tubes is studied.The main components of the internal steel guide tube involve a slender semi-cylindrical axle（small V-shaped notches are cut along the central line of the axle）which connects two semi-circular flanges,one end of the axle level with the semi-circular flange and the other end going through the semi-circular flange.During the positioning of the stay cable guide tubes of cable-stayed bridge,after preliminary positioning,the internal steel guide tubes are threaded through the stay cable guide tubes,use the internal steel guide tubes to transform the coordinates of the tube-out-of-pylon points and the coordinates of theoretical anchoring points from imaginary points to actual ones,carry out direct accurate re-measuring and positioning for stay cable guide tubes,and then use the spatial straight line equation of the two coordinate points to judge the actual measuring points.The technique has been used to the Second Jiaojiang River Bridge in Taizhou City.The engineering practice proves that the technique is able to realize the accurate positioning of the pylon-end stay cable guide tubes of cable-stayed bridge in a simple and rapid manner and the accuracy is within 5mm.