さく孔深さの影響を考慮した長尺さく孔データと岩盤特性の関係に関する検討

1.はじめに

2.トンネルの概要およびさく孔探査・TBM掘削データ

 2・1 トンネルの概要

 2・2 さく孔データ

 2・3 TBM掘削データ

3.正規化したさく孔速度と掘削体積比エネルギー

4.TBMデータから求めた岩盤強度と地質性状の関係

 4・1 岩盤強度と坑壁観察に基づく地質性状の関係

 4・2 岩盤強度と支保パターンの関係

5.さく孔データと岩盤強度・地質性状の関係

 5・1 区間@(TD850m〜1,320m

 5・2 区間A(TD1,650m〜1,920m)

 5・3 区間B(TD2,650m〜2,900m)

 5・4 区間C(TD2,920m〜3,120m)

6.断層破砕帯におけるさく孔データ

 6・1 鈴鹿花崗岩中の小断層

 6・2 鮎川層群中の小断層

 6・3 鈴鹿花崗岩と鮎川断層の境界断層(黒滝断層)

7.まとめと今後の課題

参考文献

キーワード:岩石,凝灰岩,クリープ,三軸圧縮試験,可視化,横方向変形


Correlation between Drilling Data and Rock Mass Properties Focused on the Effect of Hole Length

Abstract

On tunnel excavation, a prediction of geological conditions ahead of face is of the utmost importance to keep rapid driving and safety works. Fukui et al. in 2004 investigated the drilling performance at Suzuka tunnel with special care to the effect of hole length up to 50 m, and proposed V*(normalized penetration rate) to estimate rock mass properties ahead of face. In this study, the method proposed by Fukui et al. was fully discussed and slightly modified. Thereafter, the method was applied to estimate rock mass properties at Suzuka tunnel and systematic in-situ measurements of V* were carried out through the tunnel. It was found that the reciprocal of V* is a good indicator for rock mass properties and suits the in-situ usage. The reciprocal of V* has strong correlation with rock mass strength estimated by TBM cutting force and very useful to estimate and predict the rock mass properties ahead of face. For example, a fracture zone can be predicted by an abrupt change of the magnitude.

Key words: rock drill, long-hole drilling, tunnel, forefield exploration, rock mass property