Study on the behavior of concrete lining and rock mass during shaft excavation by means of short step method

Sakai, Kazuo*; Koike, Masashi*; Aoki, Tomoyuki*; Yamamoto, Takuya*; Hatsuyama, Yoshihiro*; Yamazaki, Masanao

In a construction project of the Horonobe URL, vertical shafts are excavated now by the Short Step method. This paper examines the behavior of concrete lining and rock mass around the shaft. To reflect the excavation sequence, a 3-D analysis is performed, modeling rock mass and support members around an advancing face. The analysis shows well specific phenomena of the Short Step method, as in the rock mass displacement and lining stress. It also reveals lining stress distribution are complex. In future, it is important to investigate lining stress through detailed measurements.