Field monitoring and stability analysis of underground crude oil storage caverns in construction phase

Field monitoring is one of the important methods to ensure construction and operation safety of large underground facilities. The construction of underground crude oil storage caverns just commences in China. There are no standards of field monitoring and examples for data analysis. Based on the experience on the first crude oil storage caverns in China, the monitoring principles and implementation method of underground crude oil storage caverns are introduced by fully considering engineering features, geological conditions and economic applicability. The monitoring results show that surrounding rock convergence, crown settlement, internal displacement and surrounding rock loose circle of most monitoring sections are in the ranges of 4~8 mm, 3~6 mm, 4~8 mm, 0.9~1.8 m, respectively, and the anchor bar stress and contact stress are less than 50 MPa and 0.5 MPa, respectively. It is concluded that: (1) The deformation and support stress of the rock mass are low. Its stability is good and the design of support scheme is reasonable. (2) The monitoring results from a comprehensive scheme can reflect the overall stability of the underground crude oil storage cavern. (3) The stability has the characteristics of spatial and time evolution.