Parameter sensitivity of rock mass integrity for a pilot underground crude oil storage caverns during construction phase

Underground crude oil storage caverns with the containment of groundwater is one of the methods for storage of crude oil. In the method, the containment property of saturated rock mass is taken advantage. Therefore, the integrity of rock mass is of great importance for the construction of underground crude oil storage caverns. Triaxial compression tests have been performed to determine the properties of the rock mass of a pilot underground crude oil storage caverns. The parameter sensitivity analysis of rock mass integrity is performed for a pilot underground crude oil storage caverns subject to construction. According to the test results, it is found that the integrity of rock specimen is damaged at the occurrence of volumetric dilation. The friction angle at this point could be used to determine the excavation induced loose zone in the construction of underground facilities. The extension of the excavation induced loose zone and the degree of loose in the zone are more sensitive to friction angle than to dilation angle. The change in stress distribution in pillar of caverns is more sensitive to friction angel than to dilation angle. The crown settlement is more sensitive to friction angle to dilation angle, but side wall convergence is sensitive to both friction angle and dilation angle. This study could be helpful in the assessment of rock mass integrity and in the design of containment system for underground crude oil storage caverns.