隧道整体贯通前无砟轨道铺设的测量技术实践

Practice in measurement technology of ballastless track construction before the extra-long tunnel breakthrough totally

以某铁路隧道工程实践为例,针对其没有建立CPⅠ/CPⅡ控制网,且前期采用线路坐标系、后期采用施工独立坐标系施工掘进的特殊情况,从施工独立控制网的可利用性分析技术、施工独立坐标系长度投影变形分析技术、隧道实际中线及建筑限界的高精度联测技术、洞外线路中线纳入洞内中线整体拟合技术、基于建筑限界满足要求确定铺轨理论中线技术等方面进行论述,提出了实测边长差异变化量的长度投影变形分析法,兼顾建筑限界的最小二乘拟合法,保证了后续掘进段落的中线与已铺轨段落的中线衔接一致,解决了隧道整体贯通前进行无砟轨道分期铺设的工程难题。隧道已经通车安全运营近3年,可供特长隧道先期铺设无砟轨道参考借鉴。

In this paper,taking a railway tunnel engineering practice as an example,aiming at the special situation that the CPⅠ/CPⅡ control network is not established,and the line coordinate system is adopted in the early stage and the construction independent coordinate system in the later stage,this paper discusses the usability analysis technology of construction independent control network,length projection deformation analysis technology for construction independent coordinate system,high precision connection surveying technology of tunnel actual center-line and location of construction clearance,total least square fitting technology of center-line in tunnel and outside tunnel,the technology of determining the theoretical center-line of track laying based on meeting the requirements of construction clearance,etc.. The method of length projection deformation of difference between measuring value and adjusted value of length is adopted,and the least square fitting method of construction clearance is taken into account,which ensure that the center-line of the subsequent tunnelling paragraph is in line with the center-line of the paved paragraph.and solves the engineering problem of laying ballastless track by stages before the extra-long tunnel breakthrough totally. The tunnel has been operated safely for nearly three years,which can be used as a reference for laying ballastless track before the extra-long tunnel breakthrough.