Study on the stability of rock mass around large underground cavern based on numerical analysis: A case study in the Cai Mep project
Hanoi University of Mining and Geology, Hanoi, Vietnam
- Received: 8th-Nov-2021
- Revised: 24th-Feb-2022
- Accepted: 21st-Mar-2022
- Online: 31st-July-2022
- Field: Civil Engineering
Geotechnical problems are complicated to the extent and cannot be expected in other areas since non-uniformities of existing discontinuous, pores in materials and various properties of the components. At present, it is extremely difficult to develop a program for tunnel analysis that considers all complicated factors. However, tunnel analysis has made remarkable growth over the past several years due to the development of numerical analysis methods and computer development, given the situation that it was difficult to solve the formula of elasticity, viscoelasticity, and plasticity for the dynamic feature of the ground when the constituent laws, yielding conditions of ground materials, geometrical shape and boundary conditions of the structure were simulated in the past. Actual problems have been successfully analyzed in addition to simple analysis and more reasonable design and construction management materials have been obtained. The stability of rock mass around an underground large cavern is the key to the construction of large-scale underground projects which have to divide into different parts stages. Rock bolt and shotcrete are important means to ensure the stability of the underground cavern. The objective of the paper is to evaluate the stability of a large cavern in the Cai Mep project in Ba Ria- Vung Tau by numerical method. The results from numerical simulations show that the stability of rock support of the cavern is in fair agreement with the original design calculation. The maximum displacement of rock mass surrounding caverns, maximum compressive stress and tensile stress in shotcrete, and the maximum axial force of rock bolt obtained by Rocscience -RS2- Phase2 software are the main parameters in the stability assessment.
Chang S. B., Moon H. K., (1998). A Study on the Quantitative Evaluation of the Load Distribution Factors Considering the Design Conditions of Tunnel Especially for the Ring-cut Excavation Method. Geotechnical Engineering Vol.14 No.5, pages 5-15, Korean Geotechnical Society.Gu, S., Zhou, P., Sun, W., Hu, C., Li, C., Wang, C., (2018). Study on the Stability of Surrounding Rock of Underground Circular Cavern Based on the Anchor Reinforcement Effect. Advances in Civil Engineering. Volume 2018, Article ID 4185070, 18 pages. https://doi.org/10.1155/ 2018/4185070.Hoek, E., Diederichs, M.S. (2006). Empirical estimation of rock mass modulus. International Journal of Rock Mechanics and Mining Sciences, 43: 203-215.Hyosung VINA Chemicals Co.,Ltd., (2019). Report on technical design of underground storage Cai Mep-LPG-CV-GR-U-0002. Vung Tau.Palmstrom A., Broch E., (2006). Use and misuse of Rock mass classification systems with particular reference to the Q-system. Tunnels and Underground Space Technology, 575-593.Ren, Q., Xu, L., Zhu, A., Shan, M., Zhang, L., Gu, J., Shen, L., (2019) Comprehensive safety evaluation method of surrounding rock during underground cavern construction, Underground Space, 6(1): 46-61. https://doi.org/10.1016/j.undsp.2019.10.003Rocscience Inc., User’s Guide, 1998-2001, 2D finite element program for stresses and estimating support around underground excavations. Rocscience Inc.Vo, T. H., Phung, M. D., (2005). Rock mechanics applying in the underground construction and mining. Publishing House for Science and Engineering, Hanoi, Viet Nam. 460 pages.Yu, Y. and Xuebao, G., (2008). Stability study of large underground caverns under high geostress September. Chinese Journal of Rock Mechanics and Engineering 27:3768-3777.Yu, Y. and Xuebao, G., (2012). Study of stability and supporting measures of chamber arch crown for large span underground caverns. September. Chinese Journal of Rock Mechanics and Engineering 31:3643-3649.