Rock mass classification and support for cavern analysis

• Main Author: Chia, Emmanuel Song Jie
• Other Authors: Zhao Zhiye
• Format: Final Year Project
• Language: English
• Published: 2017
• Subjects: DRNTU::Engineering::Civil engineering
• Online Access: http://hdl.handle.net/10356/70688
• Institution: Nanyang Technological University

Q-system and Rock Mass Rating (RMR) are common and dependable rock classification systems used widely by rock engineering industry to distinguish different quality of rocks. These rocks have rock mass properties such as rock strength and deformation modulus, which varies according to their qualities and in turn influence the stability of the rock cavern. Other factors such as the use of supports like bolting and shortcrete also contribute to the cavern’s stability but the focus of this report will be on the characterization of rock mass. With the shortage of land, rock engineering has become increasingly important in Singapore as the government explores the use of underground spaces. Even though several excavation projects have been successfully completed in Singapore, such as the Jurong Rock Cavern (JRC) project, much research is still ongoing to discover safer and more efficient ways for underground construction of caverns. This study will explore the effects of cavern dimensions and in-situ stress ratio, applied across five different quality of rocks, through the use of rocscience programme which judges stability based on critical Strength Reduction Factor (SRF) values. It will also evaluate JRC’s choice of 20m by 27m as their primary cavern dimension and suggest an alternate set of dimensions which may be safer.