School of Geospatial Information, Information Engineering University

为控制隧道控制网平差时的误差累积问题,提高隧道控制网平差精度,设计了3种约束方案。首先,考虑到测站铅垂线之间的不平行性,依据控制网规模计算测站铅垂线与储存环中心铅垂线之间的夹角,在平差时顾及该约束,使平差模型更加严密。然后,为提高隧道控制网的平面精度,使用全站仪对距离较远的控制点进行长边夹角测量,在平差过程中附加长边夹角约束。其次,按照一等水准规范,对隧道地面点进行水准测量,基于水准测量结果,采用最小二乘转换方法,将控制网转换至水平面,进一步提高控制网竖向精度。最后,对周长为1360m的隧道控制网进行仿真试验。结果表明,顾及测站垂差及水准点高程或高差平差值可提高控制网竖向精度;附加长边夹角约束可提高控制网平面精度;同时顾及测站垂差、长边夹角观测值及水准高程或高差平差值可提高控制点的点位精度,验证了约束条件的有效性。研究成果可为相关工程布设控制网提供参考。

To control the error accumulation problem and improve the accuracy of the adjustment of tunnel control network, this study designed three constraint schemes. Firstly, considering the non-parallelism between the plumb- lines of the station, the angle of the plumb-line between the station and the storage ring center was calculated based on the control network. This constraint condition was taken into account during adjustment, making the adjustment model more rigorous. Secondly, in order to improve the plane accuracy of the tunnel control network, a total station was used to measure the long side angle of the control points that were far away, and the angle constraint was added in the adjustment process. Thirdly, the first-order levelling measurement was carried out for tunnel ground points. Based on the results of levelling, the control network was transformed to the horizontal plane by using the least square transformation method to further improve the vertical accuracy of the control network. Finally, a simulation experiment was conducted on a tunnel control network with a circumference of m. The results indicate that considering the difference of the plumb-line between stations and benchmark leveling or elevation difference and adjustment value can improve the vertical accuracy of the control network. Adding the constraints of the angle of the long side can improve the plane accuracy of the control network. Simultaneously considering the angle of the plumb- line between stations, long side angle observation values, and benchmark leveling or elevation difference and adjustment value can improve the accuracy of control point positions, verifying the effectiveness of constraint conditions. The research results can provide a reference for the deployment of control networks in related engineering projects.

国家自然科学基金项目(41974216)