基于强度折减法的盐岩地下储库腔群安全稳定性研究  

SECURITY AND STABILITY RESEARCH FOR SALT-ROCK GAS STORAGE CAVERNS GROUP BASED ON STRENGTH REDUCTION METHOD

作　　者：贾超[1] 李朋[1] 张强勇[1] 

机构地区：[1]山东大学土建与水利学院,山东济南250061

出　　处：《岩石力学与工程学报》2012年第A02期3666-3672,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展计划(973)项目(2009CB724607);山东省优秀中青年科学家科研奖励基金(BS2011NJ012)

摘　　要：将强度折减理论引入到盐岩地下储气库库群的安全稳定性研究中,提出库群失效破坏的临界标准。静力分析以塑性区贯通作为失效破坏临界判据,长期流变分析中失效破坏的临界判据包括塑性区贯通以及腔体体积收缩达到极限值。腔群整体安全系数计算通过搜索折减系数F,将岩体力学强度参数按F进行折减,使模型计算结果正好达到库群失效破坏的临界标准来实现。以金坛盐岩地下储气库为例,利用FLAC3D软件建立库群数值模型,根据强度折减理论对其进行静力分析和长期流变分析,获得不同条件下的库群整体安全系数。计算表明:静力分析中,随着折减系数的不断增大,腔周塑性区不断发展,腔群的整体安全系数为2.25;长期流变分析中,随着折减系数的增大,储库腔群的主要破坏因素由体积收缩逐渐转变为塑性区的发展贯通,在与静力分析相同的数值模型及内压条件下,库群运行50 a的整体安全系数为1.83。同时,探讨安全系数同矿柱间距、压强工况以及库群破坏模式之间的关系,为类似盐岩储气库库群安全运营和稳定性评价提供科学依据。Strength reduction theory is introduced into security and stability research of the underground gas storage caverns group,and critical failure criterion of caverns is put forward.In the static analysis,critical failure criterion is transfixion of equivalent plastic strain among caverns.In the long-term rheological analysis,critical failure criterions include transfixion of equivalent plastic strain among caverns and the limiting shrinkage state of caverns volume.Rock material strength parameters are reduced by reduction factor（F） step by step and the general safety factor of caverns is obtained when the calculated results just reach critical failure criterions.Jintan salt-rock underground gas storage is taken as an example.Numerical model is created by using the software of fast lagrangian analysis of continua in three-dimention（FLAC3D） and the model is analyzed both in static state and long-term rheological state based on strength reduction theory.The general safety factors of caverns are obtained in different conditions.In the static analysis,equivalent plastic strain among caverns develops continually with the increasing of the reduction factor and the general safety factor of caverns is 2.25.In the long-term rheological analysis,the key failure factor of the caverns transforms gradually from volume shrinkage to transfixion of the equivalent plastic strain among caverns.With the same numerical model parameters and internal pressure as the static analysis,the general safety factor of caverns is 1.83 after the system operates for 50 years.The relationships among safety factor,pillar spacing,pressure condition and failure mode are discussed.It is useful for safe operation and stability evaluation to other similar salt-rock underground gas storages group.

关 键 词：岩石力学 储库腔群 强度折减 安全系数 静力分析 长期流变分析 

分 类 号：TU45[建筑科学—岩土工程]