多点后方交会法在地铁竖井联系测量中的应用

竖井联系测量工作的可操作性及准确性对矿山法隧道施工至关重要。以广州市轨道交通21号线某标段2号隧道为研究对象,基于施工竖井结构及现场环境的特殊性,对用于辅助测量的4根钢丝距离和角度进行观测,再利用多点后方交会及钢丝坐标传递原理实现井上和井下坐标传递。研究表明,在隧道开挖至40~60 m、100~150 m、贯通前150~200 m处3个位置开展联系测量工作,可获得井下控制点坐标和方位;利用测量基线指导隧道施工,隧道最大横向贯通误差为38.8 mm,横向贯通限差为±100.0 mm,贯通测量成果良好。结果表明:基于多点后方交会法联系测量技术在地铁竖井联系测量工作中可以快速实现高精度的坐标、方位传递,指导隧道施工,弥补传统常规联系测量方法的不足。

Application of Multipoint Rear Intersection Method in Connection Survey of Subway Shaft

The operability and accuracy of shaft connection survey is important to tunnel mining method construction.The 2#tunnel of a section of Guangzhou Metro Line 21 was used for research.Based on the construction of shaft structure and environment of the site,the distance and angle of 4 steel wires used for auxiliary measurement were observed,and the coordinate transfer function of borehole and downhole was realized by using multi-point resection and wire coordinate transfer principle.The research shows that the coordinate and azimuth of the control points can be obtained when the tunnel is excavated to 40~60 m,100~150 m and 150~200 m before the construction process is completed.While the survey baseline is adopted to guide the tunnel construction,the maximum transverse penetration error of the tunnel is 38.8 mm,the transverse penetration limit difference is±100.0 mm,and the result of penetration measurement is qualified.The results show that the technology based on the multi-point resection method can efficiently realize the highprecision coordinate and azimuth transmission in the subway shaft connection survey work,which can guide the tunnel construction and make up for the deficiency of the traditional connection survey method.