基于能量判据的盐岩库群整体稳定性分析方法

GLOBAL STABILITY ANALYTICAL METHOD OF CAVERN GROUP IN SALT ROCK BASED ON ENERGY CRITERION

针对能源储备地下库群整体稳定性评价,发展考虑有限元强度折减法的变形稳定理论,建立基于K-?E关系曲线的库群整体稳定性和破坏的关键判据,其中,K为强度折减系数,?E为塑性余能范数。塑性余能范数是不平衡力的范数,其大小表征库群整体稳定性;不平衡力明确展现库群失稳破坏的部位和模式。研究单储库、双储库、多储库以及金坛盐矿油气储库群的整体稳定性和失稳破坏演化规律。考虑洞径、洞距、夹层、内压、失压和布置方式等多种因素的影响,从而确定最大洞径,最小洞室间距以及库群最小稳定内压和最优布置方式。研究表明。

In order to assess the global stability of underground cavern group for energy reserves,deformation stability theory which considers the strength reduction approach of finite element method is developed.The global stability criterion of cavern group is established based on the K-DE relation,where K is the strength reduction factor and DE is the plastic complementary energy norm.The plastic complementary energy norm is the norm of unbalanced force,whose magnitude indicates the global stability of cavern group.The unbalanced forces clearly exhibit the position and pattern of the unstable failure.The global stabilities and unstable failure evolution laws of the single cavern,double cavern,multi-cavern and Jintan oil-gas storage cavern group in salt deposit are studied.Multiple influencing factors such as cavern diameter,cavern spacing,weak intercalation,internal pressure,pressure loss and cavern layout are considered.As a result,the maximum cavern diameter,the minimum cavern spacing,the minimum stable internal pressure and the optimal layout mode of cavern group are determined.The results show that the deformation stability theory provides practical and effective theory and method for the global stability assessment and unstable failure analysis of cavern group.