In this study, non-blasting tunnelling methods in hard granite are discussed based on the actual tunnelling results and in-site testing data. Machine tunnelling with a TBM is excluded from this discussion.
Followings are obtained from the study.
1. The boring of the slot is very important because it not only provides the starting position of secondary demolition but also cuts off the tunnel face from the remaining side rock.
2. The preparatory demolition operation with expansive cement, hydraulic wedge or hydraulic fracturing equipment is highly advisable.
3. The efficiency of the secondary demolition with hydraulic breakers depends a lot on the weight of the breakers.
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