A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Deformation behaviour of a large underground cavern
Summary The Imaichi underground power station, with a cross sectional area of 1420 m2, which is now under construction by Tokyo Electric Power Co., Inc., is one of the largest underground caverns in the world. Due to the considerable depth of the over-burden of 400 m, the horseshoe-shaped section was adopted for the first time in Japan to minimize excesive stress concentration on the surrounding bedrock and keep loosened zones to a minimum. The bedrock consists of sandstone, slate, siliceous sandstone and breccia. The rock is generally hard and compact, with few fractured zones which may have an adverse influence on the excavation of the cavern. The supporting system of the cavern consists of prestressed rock anchors, rock bolts and shotcrete. Approximately 800 instruments, mainly multiple stage extensometers, were used to monitor behaviour of the surrounding rock during excavation of the cavern. With the exception of some cracks which occurred in a portion of the shotcrete when about half the height of the cavern had been excavated, excavation work was completed without any major trouble. In spite of the symmetrical shape of the cavern, the deformation behaviour of the surrounding rock during excavation was remarkedly asymmetric. The reason for this was concluded to be the peculiar deformation behaviour exhibited by Breccia during stress relief, as shown by in-situ rock tests, etc., and analysis of deformation data after completion of the excavation work.
Deformation behaviour of a large underground cavern
Summary The Imaichi underground power station, with a cross sectional area of 1420 m2, which is now under construction by Tokyo Electric Power Co., Inc., is one of the largest underground caverns in the world. Due to the considerable depth of the over-burden of 400 m, the horseshoe-shaped section was adopted for the first time in Japan to minimize excesive stress concentration on the surrounding bedrock and keep loosened zones to a minimum. The bedrock consists of sandstone, slate, siliceous sandstone and breccia. The rock is generally hard and compact, with few fractured zones which may have an adverse influence on the excavation of the cavern. The supporting system of the cavern consists of prestressed rock anchors, rock bolts and shotcrete. Approximately 800 instruments, mainly multiple stage extensometers, were used to monitor behaviour of the surrounding rock during excavation of the cavern. With the exception of some cracks which occurred in a portion of the shotcrete when about half the height of the cavern had been excavated, excavation work was completed without any major trouble. In spite of the symmetrical shape of the cavern, the deformation behaviour of the surrounding rock during excavation was remarkedly asymmetric. The reason for this was concluded to be the peculiar deformation behaviour exhibited by Breccia during stress relief, as shown by in-situ rock tests, etc., and analysis of deformation data after completion of the excavation work.
Deformation behaviour of a large underground cavern
Mizukoshi, Tatsuo (author) / Mimaki, Youichi (author)
Rock Mechanics and Rock Engineering ; 18 ; 227-251
1985-10-01
25 pages
Article (Journal)
Electronic Resource
English
Deformation behaviour of a large underground cavern
| Online Contents | 1985
Monitoring of behaviour of underground powerhouse cavern
| British Library Online Contents | 1994
Monitoring of Behaviour of Underground Powerhouse Cavern
| British Library Online Contents | 1994
Rock Behavior of Large Underground Cavern During Excavation
| British Library Conference Proceedings | 1997
Observational construction management for large underground cavern excavation
| British Library Conference Proceedings | 1999