Abstract: To monitor the tunnel primary support, relying on the Shimengang tunnel and the Songgangshan tunnel of the high-speed railway line from Ganzhou to Shenzhen, field monitoring on the displacement of primary support of the tunnel is carried out. Firstly, the monitoring data was classified and summarized according to the surrounding rock level, tunnel depth and construction method. And then, by taking the exponential, logarithm and hyperbolic functions to perform a trial calculation of the envelope regression analysis on the data, the function relation formula of primary support displacement and the distance from the excavation face was obtained, and the proportion of the primary support displacement and the limit displacement of each section of the tunnel was given. Finally, compared the statistical analysis results with the current high-speed railway tunnel specifications, the suggested values of primary support displacement control standard of each section of both tunnels were given. The results show that: the primary support displacement of Ⅲ, Ⅳ and Ⅴ surrounding rock of both tunnels in the deep buried section is much shorter than the limit displacement specified by the current code. The primary support displacement control standard differs greatly from the specification. The primary support displacement of the tunnel tends to be stable after the distance from the excavation face exceeding 6 times the diameter.

Key words: high-speed railway tunnel, primary support, monitoring measurement, deformation control criterion, regression analysis