基于通用楔形管片盾构隧道曲线段线路拟合原理、算法及相关规范,提出最小曲线半径判断标准、曲线盾构隧道拟合精度评价指标等概念.分析不同管片参数能够拟合的最小曲线半径及其随管片参数变化的一般规律,并结合实际工程研究管片参数与曲线拟合精度的相关性,探讨不同管片拼装误差对曲线拟合精度的影响,提出典型参数下不同管片拼装误差的允许范围.研究表明:管片环能够拟合的最小曲线半径随管片外径减小、幅宽减小、楔形量增大而减小;楔形量增大在不明显改变管片环质量和整体尺寸的前提下能够有效提高对小半径曲线的拟合能力;管片幅宽减小、楔形量增大在一定范围内能够整体提高盾构隧道曲线段拟合精度;管片环外向偏位对管片环拟合误差影响较小,其内向偏位对拟合误差影响较大;管片环轴线偏向对管片环拟合误差影响较大,轴线内偏向的影响大于外偏向的影响.
The curve fitting algorithm of curved shield tunnels assembled by universal wedge segments was discussed, based on which,the concepts including the criteria of minimum curve radius and the evaluation indexes of the fitting precision of the curved shield tunnel were proposed. Through the analysis on the variation laws of minimum curve radius and fittin g precision versus typical segment ring parameters, and combined with engineering practice, the influence of different assembling error types on the fittin g precision of subsequent rings was discussed and the allowable ranges of the assembling errors were calculated. The results of this study indicated that the minimum curve radius that segment rings could fitdecreased along with the reduction of the ring diameter and width , and increment of the ring taperness. The increment of the taperness could significantly improve the fitting ability of segment rings for small-radius curve without observably changing the weight and size of the whole rings. The decrease of the width of the segment rings and increase of their taperness could improve the curve fittin g precision in a specific range. The assembling errors of subsequent segment rings were less affected by the initial outward deviation of segment rings, but significantly affected by the in itial inward deviation, and initial disorientation of the axis of segment rings. The impact of initial inward diso-rientation outweighed that of outward disorientation on the assembling errors of subsequent segment rings.