Assessment the applicability of hollow core rockbolts in deep tunnels at JP-Ⅱhydropower station
The JP-II hydropower tunnels project is the deepest underground engineering in china, each tunnel approximately 16.7 km in length, 13m in diameter and maximum 2525m in overburden. The hollow bolts make the grouting process much more reliable, but rebar’s elongation rate only 6％ which may cause some risk in deep tunnel construction. In this paper we discuss how to use rock mechanic and construction experience from transportation tunnels of JP-II project to assess the applicability of hollow core bolts in deep hydropower tunnels. Firstly, in-situ stress along the tunnels is discussed based on measurement, site brittle failure position around the tunnel and core discing position at deep site. Then the constitutive of deep brittle rockmass and related property determine method is carried out to discuss. The boundary condition and rockmass property of numerical model are calibrated using site geophysical data in transportation tunnels. At last the elongation of hollow core botls after installed are predicted base on numerical model in different condition, i.e. excavation method, and these result used to support the decision making of hollow core bolts’ application.
Weijiang Chu Chunsheng Zhang Jing Hou
East China Investigation and Design Institute Under CHECC
国际会议
香港
英文
1-5
2009-05-19（万方平台首次上网日期，不代表论文的发表时间）