移动式三维激光扫描系统在桥面全息变形监测的应用研究

Application of Mobile Three-Dimensional Laser Scanning System in Bridge Deformation Monitoring

传统的桥梁变形监测通常依据数个独立点的变形观测数据,尚未全面把握桥梁各部分的变形状况,本文提出利用移动式三维激光扫描系统进行桥面全息变形监测的方法.以主跨400m的上承式钢桁拱桥为背景,运用该系统进行了长达半年的桥面几何形态数据采集,综合考虑桥面铺装局部破损及桥面板结构连续性的特点对桥面原始扫描数据进行去噪处理;依据去噪后点云数据的邻域点集获取桥面的拟合空间曲面;以两端桥台路面为匹配基准面,对各次拟合桥面空间曲面进行叠差分析获取桥面全息变形数据;与精密水准仪测量结果和有限元仿真分析结果的比较表明,利用移动式三维激光扫描系统和本文的数据分析处理方法获得的桥面全息变形具有较好的精度和可靠性,并较传统的桥面线形检测显著降低了对运营交通的不利影响,有较好的工程应用前景.

Traditional methods of bridge deformation monitoring usually base on deformation data of several independent points,but deformation of each part of the bridge is not fully known. A method for monitoring deformation of bridges by using mobile three-dimensional laser scanning system was presented. A steel truss arch bridge with main span of 400 m was selected as an example. The system had been used to collect the geometric shape of the bridge deck for half a year. Considering the local damage of bridge deck pavement and the continuity of bridge deck,the noise of original data of the bridge deck was reduced. Based on neighborhood points of point cloud data,the fitting surface of the bridge deck is obtained. The road of abutment was taken as the matching datum,and results of the bridge deck deformation were obtained by overlapping and analyzing the each fitting surface. Deformation results were compared with precision level measurement results and finite element analysis results. The comparison shows that using the mobile three-dimensional laser scanning system and the data processing method to obtain deformation has good accuracy and reliability. Compared with the traditional bridge detection,it significantly reduces the adverse effects to traffic. It has good prospect in engineering application.