上海地面沉降精准监测基准网构建关键技术研究

Study on key technologies of benchmark network construction for land subsidence precision monitoring in Shanghai

上海地面沉降进入微量沉降阶段,对地面沉降测量精度提出更高要求。本文基于40余年地面沉降测量数据,利用中误差、先验中误差、限差等测量误差理论,选取了连续观测时间较长、空间分布均衡的稳定基岩标组建成地面沉降监测基准网。将地面沉降水准网从一点起算的自由网优化为多点起算的附合网,避免了水准网“一点定向”的不足,有效减少了测量误差的积累,显著提升了地面沉降监测精度。自2008年实施以来,经14年的实践验证,构建的地面沉降监测基准网具有更强的稳定性和可靠性,成为微量地面沉降监测的重要测量基准。同时也成为上海轨道交通等城市生命线工程和城市基础设施正常运行安全监测的重要保障,并对长三角一体化地面沉降防控继续发挥引领作用。

The land subsidence in Shanghai has entered the stage of micro-subsidence,which puts forward higher requirements for the measurement accuracy of land subsidence.Based on 40 years of land subsidence measurement data,this paper uses the measurement error theories such as medium error,prior medium error,and tolerance,and selects stable bedrock markers with long continuous observation time and balanced spatial distribution to form a ground subsidence monitoring benchmark network.The ground subsidence leveling network is optimized from one point to the free network calculated from multiple points,which avoids the shortage of "one-point orientation" of the leveling network and effectively reduces the accumulation of measurement errors.Since its implementation in 2008,after 14 years of practice verification,the constructed land subsidence monitoring benchmark network has more significant stability and reliability,and has become an important measurement benchmark for trace land subsidence monitoring.At the same time,it has also become an important guarantee for the normal operation and safety monitoring of urban lifeline projects and infrastructure such as Shanghai rail transit,and continues to play a leading role in the integrated prevention and control of land subsidence in the Yangtze River Delta.