在地铁隧道竣工检测和运营监测中，盾构断面椭圆度是隧道变形和维修整治的关键指标，对其高效准确地测量是一项重要的工作。随着与日俱增的交通需求和施工技术的快速发展，地铁竣工验收、运维监护对断面测量的精度、效率以及信息全面性等方面的要求越来越高。介绍盾构管片椭圆度的多种测量方法和数据处理原理，并对其优劣性进行对比分析。针对盾构管片断面变形规律的复杂性，利用大量实例数据，统计分析管片椭圆的旋转角、横向收敛、椭圆度等参数的关联和分布情况，发现横向收敛与椭圆度有很强的相关性，且椭圆旋转角超过一定数值对常规水平收敛测量也有影响，即横向与水平直径的偏差不容忽视。因此，横向收敛作为管片结构安全评估的重要参数，将椭圆长轴作为收敛基线更能客观反映实际变形情况，该结果可为类似工程提供一定的参考价值。

In the inspection and operation monitoring of a completed metro tunnel, the ovality of shield sections should be efficiently and accurately measured because it is the key index of tunnel deformation and maintenance. With increasing traffic and the rapid development in construction technology, the accuracy, efficiency, and comprehensiveness of section measurements are required before the acceptance, operation, and maintenance monitoring of a completed metro project. In this paper, various measurement methods and data processing principles of shield segment ovality are introduced, and the comparison and analysis of their advantages and disadvantages are presented. In view of the complexity of the deformation law of the shield segment section, a considerable amount of case data is used to analyze the correlation and distribution of parameters, such as the rotation angle, lateral convergence, and segment ellipticity. A strong correlation was found between lateral convergence and ellipticity. In addition, when the rotation angle of the ellipse exceeds a certain value, it also impacts the measurement of the conventional horizontal convergence, i.e., the deviation between the lateral and horizontal diameters cannot be ignored. Therefore, as an important parameter for the safety assessment of the shield segment, the long axis of the ellipse should be considered as the convergence baseline to reflect the actual deformation situation more objectively, thus providing a reference value for similar projects.

U231

江苏省科技支撑计划项目(BE2014026)