m Javadi - Department of Underground Structures, Sahel Consulting Engineers, Tehran, Iran,
b ebrahimian - Department of Underground Structures, Sahel Consulting Engineers, Tehran, Iran,School of Civil Engineering, University of Tehran, Tehran, Iran,
a.n dehghan - Department of Underground Structures, Sahel Consulting Engineers, Tehran, Iran,

Hydrocarbon storage in underground facilities has rapidly grown during the last four decades due to the innovations in rock engineering and advantages of underground methods. Through underground storage methods, unlined rock cavern (URC) is the second cheapest method and is the best alternative for operational storage purposes because of their wide availability, efficiency, and flexibility in loading and unloading the liquid hydrocarbon products. However, application of URCs for storage of hydrocarbon requires more attentions for design, construction, and utilization than other usual underground excavations such as road and water supply tunnels and hydropower caverns. The complexity of different technical and engineered concerns related to the URCs for storage of hydrocarbon calls for precise and comprehensive design processes. This issue is investigated in this paper by developing a comprehensive flowchart for design of URCs for hydrocarbon storage. The aim of this paper is to present the design framework and guidelines of unlined rock caverns for hydrocarbon storage. To reach this goal, the concepts of unlined cavern utilization for hydrocarbon are firstly introduced, and a work breakdown structure is presented on the basis of the utilizations and requirements of hydrocarbon storage in unlined mined rock caverns. Then, a flowchart of design process of URCs is presented by using the structural design model based on particular aspects of the project including, input and output data, ground behavior and rock mass structure and various elements of the rock engineering system. The discussed issues in this paper prove useful and can be practically applied in different phases of technical work including feasibility study, conceptual, and detailed design analysis

Hydrocarbon Storage, Unlined Cavern, Design Flowchart, Hydraulic Confinement, Water Curtain