中文摘要：

硐室围岩的变形监测是地下工程施工中的一项重要内容，如何研制改进现有的监测仪器，获得最接近实际的围岩变形信息是工程人员非常关心的问题。介绍了新型套管式同轴多点位移计的监测原理、结构，给出了监测结果换算的理论公式。通过隧道工程的实测分析，此位移计监测获取的围岩变形信息，可以揭示硐室开挖后围岩变形规律，确定合理的二次支护施作时间和施工方法，预测大变形等地质灾害，为信息化施工提供依据。

英文摘要：

The monitoring of the deformation of surrounding rock was one of the most important contents in underground construction project. How to improve the current monitoring instruments and obtain the closest value to the actual deformation information of the surrounding rock was an interesting problem of many engineers. The monitoring principles and structure of the spigot coaxial rod extensometer （SCRE for short） were introduced. Likewise, the monitored data of theoretical conversion formula were given. On the basis of actual measurements, analysis of tunnel construction and the monitored deformation infomation of the surrounding rock, the deformation regularity of surrounding rock after the excavation of cavern was disclosed, and the optimum support time and construction method were determined. The proposed method could be employed to predict geological disasters such as large deformation and to provide basis to the information-based construction.