Abstract:

The tailrace tunnel with varying roof height of Pengshui hydropower station has such features as large excavation area, large opening ratio, thin rock pillars between tunnels and poor stability of the rock pillars. Comparison is made on the proposed highstrength rockbolting reinforcement option and the traditional noncohesive prestressed anchor cable reinforcement option. In the end, the proposed highstrength rockbolting reinforcement option is adopted, which ensures the stability of the connection between the rock pillars and the thin reinforced concrete walls and achieves good results.

Key words: tailrace tunnel with varying roof height, highstrength rockbolt, Pengshui hydropower station