A displacement-relay videometric method for surface subsidence surveillance in unstable areas

• Published in: Science China. Technological sciences 2015-06, Vol.58 (6), p.1105-1111
• Main Authors: Yu, QiFeng, Jiang, GuangWen, Shang, Yang, Xu, Yong, Liu, XiaoLin, Fu, SiHua, Guan, BangLei, Zhu, XianWei
• Format: Article
• Language: English
• Subjects: c方法; Engineering; 不稳定; 位移; 地表沉降; 地面沉降监测; 测量仪器; 相机设计; 继电器
• ISSN: 1674-7321; 1869-1900
• DOI: 10.1007/s11431-015-5811-6

When measuring the surface subsidence of unstable areas such as railroad beds and large construction fields, it is not practical to always find stable positions to install measurement instruments. Yet installing those instruments in unstable positions will cause measurement errors or even the complete failure of long-term subsidence surveillance. In this paper, the innovative con- cept and its method of ＂displacement-relay videometrics＂ are proposed. With the method, a double-headed camera is designed, and two constraints, the ＂fixation constraint＂ and the ＂homologous constraint＂, are established to construct the displace- ment-relay measurement equations, which can concurrently give the subsidence of the points to be measured and the positions where the cameras are fixed. The method and its measurement system are thus capable of automatically measuring the surface subsidence under the condition that the cameras are mounted on unstable locations over long durations. Therefore, the method has the broad prospect of undertaking automatic, long-term and continuous measurement for surface subsidence in engineering projects such as railroad beds, bridges and the ground beds of tall buildings. The proposed method opens a new area that cam- eras can be mounted on unstable platform to make high accuracy measurements, which is of great significance for applications.