Multi-scale Block Stability Prediction Methods of Large Span Underground Cavern Group Surrounding Rock(PDF)
《地球科学与环境学报》[ISSN:1672-6561/CN:61-1423/P]
- Issue:
- 2015年第02期
- Page:
- 93-101
- Research Field:
- 工程地质
- Publishing date:
Info
- Title:
- Multi-scale Block Stability Prediction Methods of Large Span Underground Cavern Group Surrounding Rock
- Author(s):
- ZHANG Fa-ming; YU Cheng; HU Meng-jiao; HU Da-ke; LI Xue-zheng
- 1. School of Earth Science and Engineering, Hohai University, Nanjing 210098, Jiangsu, China; 2. PowerChina Zhongnan Engineering Corporation Limited, Changsha 410014, Hunan, China
- Keywords:
- complex rock mass; geometry-mechanics coupling; structural surface; block; stability analysis; geological mechanism; underground cavern
- PACS:
- P642.3;TU457
- DOI:
- -
- Abstract:
- The surrounding rock of underground cavern is a structure with different scales and forms carved by structural surface in different scales. These structures are the main factors causing the instability of surrounding rock during the construction period, and the specific location is uncertain before the excavation of underground cavern, so that it is difficult to reinforce the surrounding rock. It is important to predict the outcrop position of structure surface on the excavation surface based on the genesis and scale of structural surface with different scales, according to the structure surface data investigated by exploration cavern. From the genesis of structural surface, structure model of surrounding rocks of large span underground cavern was built by geometry-mechanics coupling simulation method. The fitting of large scale fault, fracture zone and bedding surface was calculated according to the mechanical genesis and fault mechanism. The fitting of random structural surface was calculated with random simulation method by the characteristics of joint persistence ratio of structural surface according to the statistical results of field structural surface. Geometric forms of blocks composed by structural surfaces were confirmed based on orthogonal test and block theory, the distribution of multi-scale blocks was searched, and the distributions of special, semi-special and random blocks were found. Further, the blocks, which might be destroyed, were found and reinforced on the excavation surface of cavern by ultimate balance theory. Finally, the program UNDGD2.0 was developed to analyze the stability of multi-scale structural surface combination based on the geometry-mechanics genesis. A pumped storage power station under construction was taken as an example, the types and scales of block combination on different excavation surfaces in underground cavern were searched, and the stability of partial blocks composed by structural surfaces was analyzed in order to confirm and design optimally the excavation scheme of underground cavern. The results show that the research findings are rational.
Last Update: 2015-04-02