关键词: 地下工程, 隧道, 监测方法, 激光收敛测量, 现场测量试验, 精度评估

Abstract: A new laser convergence monitoring method is proposed, combining with the advantages of the current two measurement methods, i.e. traditional convergence measurement and total station measurement. For the traditional convergence measurement method and total station measurement method, both have some disadvantages, such as high operation requirements, the construction disturbance and difficult to long-term monitoring, etc. risen from by the former, and lower accuracy raised by the latter. Laser ranging technology used by total station measurement has been adopted, at the same time direct-measure strategy used by traditional convergence measurement also has been followed. By virtue of the existing laser ranging products, the measuring apparatus required by the new method has been designed and processed out. The apparatus consists of five parts which are laser rangefinder, rangefinder base, connecting rod, connecting sleeve and measuring base. According to the specific implementation steps, the measurement precision in on-site engineering environment has been tested and estimated in the tunnel of Chengchao Iron. The test results show that the new method is low-cost, simple operation, good stability, and the measurement precision can reach 0.7 mm. Therefore it is useful for universal application of convergence monitoring to the process of construction of underground engineering.

Key words: underground engineering, tunnel, monitoring method, laser convergence monitoring, on-site test, precision assessment