液-固-土耦合下黄土区大型储液罐群的多维地震动响应及振动控制研究

It is difficult to accurately grasp the mechanical behavior and failure reasons of liquid storage tank under earthquake action. Smaller spacing will result in interaction between adjacent tanks through the foundation; in addition, loess is very sensitive to dynamic action, so the liquid storage tanks in loess area will be in a more complex stress state. Based on the early research foundations on seismic control of liquid storage structure and composite foundation of liquid storage tank in loess area, considering group effect, liquid-solid-soil interaction, loess dynamic characteristics and multi-dimensional earthquake, a three-dimensional numerical calculation model of liquid storage tank group in loess area will be established, and the rationality of the calculation model will be verified by shaking table test. In order to quantitatively study the influence of group effect on dynamic responses and dynamic stability of composite foundation of liquid storage tanks in loess area, a group effect evaluation method based on dimensionless index will be proposed, and the failure mechanism of composite foundation will also be revealed. Besides, the mathematical model between system responses and influence parameters will be established, and the influence of each parameter on the group effect will be evaluated by the dimensionless sensitivity. Based on the study of group effect, the vibrating barrier device of foundation will be developed, the control effect of isolation, vibrating barrier device and isolation + vibrating barrier device on the dynamic responses and group effect of liquid storage tanks in loess area will be discussed, and the optimal vibration control method will be put forward. It will provide a theoretical basis for the engineering application and an effective way for earthquake disaster prevention of liquid storage tanks in loess area.

地震作用下储液罐的力学行为和破坏原因难以被准确把握。较小的间距将导致相邻储液罐通过地基产生相互影响，再加黄土对动力作用十分敏感，从而使得黄土区储液罐会处于更加复杂的受力状态。本项目结合前期储液结构减震控制和黄土区储液罐复合地基已有研究基础，拟考虑群效应、液-固-土耦合、黄土动力特性及多维地震，建立黄土区储液罐群三维数值计算模型，并借助振动台试验验证计算模型的合理性。提出基于无量纲指标的群效应评价方法，定量化研究群效应对黄土区储液罐动力响应及复合地基动力稳定性的影响规律，并揭示复合地基破坏机理；同时建立系统响应与影响参数之间的数学模型，由敏感度评价各参数对群效应的影响大小；在群效应研究基础上，研发地基振动屏障装置，探讨隔震、振动屏障装置及隔震+振动屏障装置对黄土区储液罐群动力响应和群效应的控制效果，提出最优振动控制方法。进而为黄土区储液罐的工程应用提供理论依据，为其地震灾害预防提供有效途径。

地震作用下储液罐的力学行为和破坏原因难以被准确把握，储液罐往往成群布置，较小的间距将导致相邻储液罐通过地基产生相互影响，从而使得黄土区储液罐会处于更加复杂的受力状态。首先，考虑群效应及液-固-土耦合，建立了黄土区储液罐的三维数值计算模型，基于群效应影响系数定量化研究了结构-土-结构相互作用对黄土区储液罐动力响应的影响规律，得到群效应对壁板有效应力、液体晃动波高和地基水平位移都有着明显的放大作用。其次，在群效应对地震响应影响规律的研究基础上，研发了地基振动屏障装置，探讨了振动屏障装置对黄土区相邻储液罐动力响应的控制效果，得到振动屏障装置对于相邻储液罐自身地震响应和液体晃动波高都具有显著的控制效果，进而提出了相邻储液罐的新型振动控制方法。再次，在基于振动屏障控制储液罐地震响应的基础上，针对单个储液罐又开展了减震控制研究，考虑液-固-土耦合效应，探讨了滑移隔震-限位耗能混合控制及隔震-摆式TMD混合控制对储液罐动力响应的减震效果，并且对比研究了不同震源机制近断层脉冲地震作用下隔震与非隔震储液罐的动力响应，得到混合控制体系对于储液罐的减震效果显著。最后，考虑极端情况，基于概率方法研究了地震作用下隔震储液罐的碰撞问题，得到近场脉冲地震作用下隔震储液罐的碰撞概率最大，增大初始间隔能够显著降低碰撞概率。本项目研究成果可为黄土区储液罐的减震设计提供理论依据，并为其防震减灾提供有效的途径。