盐岩密集储库群布置方式优化及连锁破坏研究

STUDY OF LAYOUT OPTIMIZATION AND CHAIN DESTRUCTION OF DENSE STORAGE GROUP IN SALT ROCK

将基于不平衡力和最小塑性余能范数的地下洞群稳定性判别方法引入FLAC3D,推导其在FLAC3D中的等价形式,并证明可以用最大不平衡力和塑性区范围判断库群的稳定性,用FLAC3D中的不平衡力分布和调整过程表征库群的破坏位置和扩展路径。从合理的储库间距和密集库群的平面布置形式这2个方面对密集储库群的布置方式进行优化,指出1.5倍洞距为经济安全洞距,正三角形布置为库群最优化的平面布置形式。对库群中的2种破坏源进行对比计算,结果表明非边缘腔为破坏源时,对库群整体稳定性的影响较边缘腔为破坏源时更大。采用正三角形布置方式,先对单个非边缘腔突发失压的工况进行稳定性分析,考虑盐岩长期强度的折减,再对同一模型进行稳定性分析,并将结果应用于库群连锁破坏分析中,作为确定先期失稳部位的依据。对库群进行连锁破坏数值计算分析,结果表明单腔突发失压不易引起库群连锁破坏。

The stability criterion for underground caverns based on the unbalanced force and the minimum plastic complementary energy is introduced into the software fast Lagrangian analysis of continua in three dimensions （FLAC3D）,and its equivalent form is deduced. The rationality of using the maximum unbalanced force and the plasticity distribution to determine the stability and using the unbalanced force distribution and adjustment process to indicate the destruction location and evolution path of storage group is demonstrated. The layout of dense storage group is optimized from two aspects of the reasonable space between two caverns and the layout pattern,respectively. The results show that distance 1.5 times of cavern diameter is safe and economic between two caverns;and equilateral triangle layout is the optimal plane layout pattern. Two kinds of destruction sources in the storage group are compared. The results show that the influence of sudden pressure loss starting from internal caverns is more significant and cause more serious damage than that from the outlying caverns. The stability of single internal cavern with sudden pressure loss is analyzed by using equilateral triangle layout. Considering the long-term strength reduction of salt rock,the stability of the same model is carried out. The results are applied to the chain destruction analysis later as an indicator of local failure. The chain destruction process is studied by numerical simulation;and the results show that the sudden pressure loss in single cavern doesn′t tend to cause chain destruction of storage group.