ABSTRACT
In order to meet the needs of monitoring the deformation of surrounding rock in large sections, soft rock medium tunnels and underground engineering, a free station method based on the electronic total station is put forward in this paper, where the principle, implementation process, target design and protection, and measurement system error analysis of convergence measurement of the surrounding rock are described in detail. This method can quickly and accurately complete the subsidence of the surrounding rock vault and headroom convergence. Moreover, it can meet the requirements of tunnel monitoring and measurement accuracy and overcome the disadvantages of traditional convergence gauges, such as high safety risk, difficult operation, and slow measurement speed, boasting the advantages of small construction interference, high speed and non-contact, which provides a new test method for underground engineering construction monitoring.
