利用地面三维激光扫描进行桥梁挠度变形分析

针对常规桥梁挠度变形分析方法仅能获取有限数量离散监测点的几何变形,且存在自动化程度低、效率低、局限性大的问题,本文提出了一种基于点云数据的桥梁挠度变形分析方法。首先通过地面三维激光扫描仪获取桥梁变形体上的点云数据,经过精确配准,获取可靠点云数据。然后利用滑动窗口法得到桥梁线形,并通过两期线形叠差分析得到桥梁挠度变化。最后以跨度40 m+65 m+40 m的连续钢构桥实体工程为试验对象,利用本文方法发现该桥梁存在最小值为8 mm、跨中最大值为17.5 mm、平均值为14.9 mm的挠度变形。结果表明,该方法理论严密、计算效率高、简单实用。研究结果对三维激光扫描技术在变形监测领域的深度应用有重要借鉴意义。

Analysis of bridge deflection deformation based on ground three-dimensional laser scanning

Traditional methods of bridge deformation monitoring usually depend on deformation data of several independent points, which has the problems of low automation degree, low efficiency and limitations. In this article, an accurate method for bridge deflection is proposed. This method accurately registers the point cloud data of the bridge obtained by the ground 3D laser scanner. On the basis of obtaining reliable point cloud data, the bridge alignment is obtained by using the sliding window method, and the deflection of the bridge are obtained by using the difference analysis of two periods of data. Taking a continuous rigid frame bridge with a span of (40 m+65 m+40 m) as the experimental object, it is found that there are deflection deformations with a minimum value of 8 mm, a maximum value of 17.5 mm and an average value of 14.9 mm. Results prove that the method is simple and practical, with strict theory, high computational efficiency. It has important reference significance for the deep application of 3D laser scanning technology in the field of deformation monitoring.