三维激光扫描技术在公路隧道施工监测中的应用研究

Application Research of 3D Laser Scanning Technology in Construction Monitoring of Highway Tunnels

以某一隧道工程施工监测为对象,提出一种基于三维激光扫描技术的隧道断面变形监测。采用隧道外强制对中装置,将测量控制装置置于墙体有效的避免控制点变形而影响测量精度;采用全局拼接方法,通过在隧道两端设定标靶,实现点云各点三维坐标属性、反射强度、三维真彩色信息集合;通过隧道分割,根据三维不变矩平移旋转稳定特性,提取隧道中轴线姿态;利用MDP法(最小距离投影算法)进行隧道断面三维变形计算,确定隧道收敛和扩张变形量。通过降低区段选取长度,对区段间的点云信息抽稀,降低点云的密度。对比未进行抽稀和局部测量的激光扫描数据,可以发现采用该方式有效降低了监测过程中变形信号的标准差,缩短了计算量,提高了测量精度。

Based on the monitoring of the construction of a tunnel project,this paper presents a tunnel cross-section deformation monitoring based on 3d laser scanning technology.Using the external force of the tunnel,the measuring control device is placed in the wall to avoid the deformation of the control point and affect the measurement accuracy.By adopting the global Mosaic method,the three-dimensional coordinate properties,reflection intensity and three-dimensional true color information set are realized by setting the target at both ends of the tunnel.Through the segmentation of the tunnel,the axial position of the tunnel is extracted according to the stability characteristic of the 3d invariant moment translation.Using MDP method(minimum distance projection algorithm),the 3d deformation calculation of tunnel section is carried out to determine the convergence and deformation of the tunnel.By reducing the length of the section,the point cloud information between the segments is sparse and the density of the point cloud is reduced.Compare not to dilute and localized measurement of laser scanning data,can be found by using this method effectively reduces the signal in the process of monitoring the standard deviation,shortens the amount of calculation and improve the accuracy of measurement.