Two- and three-dimensional stability analysis of underground storage caverns in soft rock (Cappadocia, Turkey) by finite element method

• Published in: Journal of mountain science Vol. 19; no. 4; pp. 1182 - 1202
• Main Author: Sari, Mehmet
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.04.2022; Springer Nature B.V
• Subjects: Analysis; Caverns; Classification systems; Deformation; Deformation effects; Design; Design engineering; Dimensional stability; Earth and Environmental Science; Earth Sciences; Ecology; Environment; Finite element analysis; Finite element method; Geography; Optimization; Original Article; Preliminary designs; Rock; Rock masses; Rocks; Safety factors; Shelf life; Software; Stability; Stability analysis; Three dimensional analysis; Two dimensional analysis; Underground caverns; Underground storage; Weak rock; Cappadocia; Turkey; Numerical modeling; FEM analysis; Soft rock; Underground storage cavern; Rock mass failure
• ISSN: 1672-6316; 1993-0321; 1008-2786
• DOI: 10.1007/s11629-021-7047-1

Engineering design in soft rocks and its stability analysis exerts many challenges to rock engineers. Many engineering works in Turkey’s Cappadocia region must face and tackle the existing sites covered by the soft rocks. This study is aimed to examine the stability condition of a typical underground storage cavern (USC) excavated in a soft rock in this region. For this purpose, two- and three-dimensional stability analyses of the USCs were performed using the finite element method (FEM). Because of the inherent difficulty in characterizing soft/weak rock masses in the region using traditional classification systems, the stability of a typical USC was evaluated by representing the rock mass condition with two distinct scenarios in FEM analysis. While these structures were unstable according to the 2D analysis conducted in RS2 software in the worst-case scenario, they were stable in the 3D analysis using RS3 software in both scenarios. Besides, feasible cover depths were examined to assess their possible effects on the factor of safety and deformation measurements. It was found that 15 m seems to be an optimal depth for excavating a typical USC in the soft rocks exposed in the region. The 3D FEM results provide valuable information to optimize the future planning and preliminary design of USCs.