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.