盾构圆形隧道限界测量成果分析

Results analysis of clearance survey in circular tunnel excavated by shield method

为了更方便、快捷地完成圆形隧道限界测量,采用附有断面测量机载程序的伺服式全站仪采集各个断面上均匀点位的三维坐标,并采用最小二乘原理对数据进行处理.由于所测断面是一个空间圆,需对其测量数据进行三维拟合.首先进行空间平面拟合与球壳拟合,使点到平面或球心的距离的平方和最小,然后再根据平面和球壳的方程求空间圆的表达式.拟合时需检验残差、剔除粗差,并重新拟合,直至满足限差要求,以二倍中误差和某一定值作为限差.根据空间圆的表达式计算出断面的坡度与方位角,该值可作为检验施工质量的一个标准.最后,结合具体工程实例,通过编程对大量数据进行了统计分析,论证了该方法的正确性与可行性.

In order to complete the clearance survey of circular tunnel more conveniently and quick- ly, GeoRobot with the airborne program of section measurement is used for collecting three-dimen- sional coordinates of each homogeneous point on the section, and the data is handled by the least squares principle. As the section is generally an inclined spatial circle, the collected three-dimension-