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Abstract Reasonable distance between caverns is indispensable for the safety and normal operation of underground storage caverns. Many factors such as complex geological and operation conditions，high variability and stochastic behavior of material parameters influence the safety of caverns. In this paper，taking account of stability and sealability，Mohr-Coulomb criterion and damage-dilatancy criterion are used as main failure criterion. Then distributions of plastic area and damage-dilatancy area under different conditions under different distances between gas storage caverns and operating pressures are calculated by a two-gas storage cavern numerical calculation model. Failure probabilities of elements nearby the caverns are also calculated by response surface method combining with Monte-Carlo method. The calculation results indicate that：at normal operation conditions，plastic area and failure probabilities of elements nearby the caverns increase obviously with the decreasing distance between storage caverns. At the same time，damage-dilatancy area increases remarkably with the decreasing distance between storage caverns；the damage-dilatancy area even connects the two caverns when operation pressure is low. When operation pressures of two caverns are different，the influence of differential pressure on failure probabilities of elements nearby the caverns diminishes gradually with the increasing distance between storage caverns. According to the calculation results of stability and sealability，taking two times of cavern diameter as the minimum distance between gas storage caverns is reasonable.
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Received: 30 July 2010
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2011, Vol. 30 
