长大隧道贯通前铺轨CPⅡ导线陀螺方位约束应用探讨  

Discussion on Application of a Gyroscopic Coordinate Azimuthal Constraint in CPⅡTraverse Adjustment Prior to Long-tunnel Breakthrough

作　　者：王广科 王正邦 陈光金 付宏平 WANG Guangke;WANG Zhengbang;CHEN Guangjin;FU Hongping(The First Engineering Co.,Ltd.of China Railway Tunnel Group,Chongqing 401123,China;Shaanxi Railway and Underground Traffic Engineering Key Laboratory(FSDI),Xi′an 710043,Shaanxi,China)

机构地区：[1]中铁隧道集团一处有限公司,重庆401123 [2]陕西省铁道及地下交通工程重点实验室(中铁一院),陕西西安710043

出　　处：《隧道建设（中英文）》2021年第1期60-66,共7页Tunnel Construction

摘　　要：在隧道未整体贯通的条件下,采用边掘进边在贯通段提前实施铺轨的施工方案时,为解决利用平导、无方位角附合条件下进行相向施工的无砟轨道难以准确对接的技术难题,提出洞内CPⅡ导线采用高精度陀螺仪加测方位边保障导线方向精度的方法。通过对2种坐标方位角的精度匹配与较差限差标准、隧道铺轨建筑限界匹配检查方法、高精度陀螺仪CPⅡ导线的闭合差法检查、横向偏差与建筑限界匹配优化检查等方面进行探讨,得出特长隧道CPⅡ陀螺导线的约束应用条件为:CPⅡ导线坐标方位角与陀螺坐标方位角精度相当,坐标方位角较差及导线全长相对闭合精度满足隧道二等限差要求,与隧道建筑限界的匹配应得到优化,且洞内CPⅡ中联测的施工控制导线点横向偏差要求在隧道施工净空裕量范围(5 cm)以内。按照陀螺方位边的约束应用标准,确定隧道洞内CPⅡ导线采用陀螺方位约束的计算方法。目前,隧道已经贯通,无砟轨道铺轨全部完成,各项指标满足施工验标要求,表明CPⅡ导线采用陀螺方位约束的方法可用于隧道工程实践。When adopting a construction scheme consisting of excavation followed by laying of tracks prior to tunnel breakthrough,there is a technical problem with accurate docking of ballastless tracks through parallel adit without an azimuthal-closure check condition.Consequently,a method ensuring the directional accuracy of the CPⅡtraverse by measuring the azimuth with a high-precision gyroscope is proposed.By discussing the accuracy matching and poor tolerance standards of the two azimuthal coordinates as well as confirming the matching of tunnel-track-laying construction clearance,checking the closure error of the high-precision gyroscope,and optimizing the matching between the lateral deviation and the construction clearance,the following constraints for using a CPⅡgyroscope in an extra-long tunnel are obtained.(1)First,the accuracy of the CPⅡtraverse-coordinate azimuth and gyroscope-coordinate azimuth is almost the same;(2)the closure error of the coordinate azimuth and relative-closure errors of the extreme-length traverse meet second-class tolerance requirements for the tunnel;(3)matching of gyroscope with the tunnel-construction clearance should be optimized;and(4)the lateral deviation of the construction-control traverse points in CPⅡshould be within 5 m of the tunnel-construction-clearance distance.According to the constraints for application of gyroscope azimuth side,a method for the calculation of constrained gyroscope azimuth is determined for CPⅡtraverse in the tunnel.The results of this method show that every indicator complies with the requirements of the inspection standards of construction.This indicates the feasibility of the CPⅡtraverse-based method for the constrained gyroscope azimuth in the tunnel.

关 键 词：特长隧道 铺轨测量 CPⅡ导线 陀螺方位 约束平差 建筑限界 

分 类 号：U45[建筑科学—桥梁与隧道工程]