光电测量方法在盾构隧道收敛监测中的可行性研究

Feasibility Study of Opt Electric Measurement Methods in Convergence Monitoring of Shield Metro Tunnel

针对盾构隧道收敛监测常见的3种光电测量方法开展可行性研究,并进行对比分析。三维激光扫描技术采用静态架站式数据采集,针对获取的圆形盾构隧道点云数据利用激光雷达隧道测量检测软件进行隧道轴线输入、迭代式断面中心拟合与噪点过滤、断面提取、椭圆拟合、生成断面测点图和椭圆拟合曲线图等处理来获取隧道收敛值;TS60全站仪利用免棱镜测距功能获取收敛值,徕卡D2手持测距仪利用直接测量获取收敛值;通过对3种光电测量方法获取的盾构隧道管环横径值进行数据分析。研究表明:3种测量方法均可以满足地铁隧道收敛变形监测指标要求;针对测量误差在±3 mm内,三维激光扫描和测距仪直接测量的横径值差异较小,且分布区间较为集中;三维激光扫描与全站仪免棱镜测量的横径值差异较为分散;全站仪免棱镜与测距仪测量的横径值差异较小,分布区间较为集中。综合可知,针对隧道横径值测量,三维激光扫描和测距仪测量的效率与效果优于全站仪免棱镜测量;三维激光扫描和手持测距仪两种隧道横径测量方法在技术与精度上是完全可行并且可靠的。

Three common photoelectric measurement methods for shield tunnel convergence monitoring are studied and compared.3D laser scanning technology uses static standing type data acquisition to obtain tunnel convergence value based on laser radar point cloud data of round shield tunnel by means of tunnel measurement detection software to fulfill the processes of tunnel axis input,iterative section center fitting and noise filtering,cross section extraction,ellipse fitting,generating section figure of measuring points and ellipse fitting curve.The TS60 total station uses prism-free ranging function to obtain the convergence value,and the Leica D2 handheld rangefinder uses direct measurement to obtain the convergence value.Based on data analysis of the transverse diameter of shield tunnel pipe ring obtained by three photoelectric measurement methods,the research shows that the three measurement methods can meet the requirements of the convergence deformation monitoring index of metro tunnel.When the measurement error is within±3 mm,the transverse diameters measured by 3D laser scanning and rangefinder are less different,and the distribution intervals are more concentrated.The difference of transverse diameters between 3D laser scanning and total station prism-free measurement is relatively scattered.The diameters measured by total station without prism and range finder have little difference,and the distribution intervals are more concentrated.Based on comprehensive comparison,the efficiency and effect of tunnel cross diameter measurement with 3D laser scanningand DISTO are better than those with prism free total station;3D laser scanning and handheld rangefinder are both feasible and reliable in terms of technique and accuracy.