摘要
外罐是确保LNG储罐安全的关键设施,研究长周期地震动作用下外罐的动力性能对LNG储罐具有重要意义。本文以160000 m^(3)LNG储罐为背景,考虑了重力与预应力筋作用,采用集成化的通用结构分析与设计软件SAP2000建立外罐的三维有限元模型,分析了外罐的变形、加速度和基底剪力以便证实长周期地震动作用下外罐受力性能良好并在控制范围内,在此基础上,引入由叠层橡胶隔震支座与软钢阻尼器组成的新型并联隔震装置,分析长周期地震动对外罐隔震性能的影响,研究结果表明,由于地震动的随机性、模糊性和不确定性,外罐基础隔震设计必须考虑长周期地震动的影响。新型隔震装置对短周期地震动而言是有效的,长周期地震动作用下隔震失效;当Mexican地震动卓越周期与隔震周期接近时,隔震外罐发生共振现象,其顶点位移为El Centro地震动作用下顶点位移的2.74倍,其基底剪力为El Centro地震动作用下基底剪力的7.31倍,隔震层位移达到385.49 mm,为外罐设计提供技术支撑和理论依据。
The outer tank is the key facility to ensure the safety of the LNG storage tank,and it is of great significance to study the dynamical performance of the outer tank under the long-period ground motion.The outer tank of a 160000m^(3)LNG storage tank was taken as the research object in this study.First of all,the three-dimension finite element model of the outer tank in consideration of the gravity and prestressed tendon effects was set up by using the general structural engineering analysis and design software SAP2000.And then the acceleration,deformation,and base shear of the outer tank were analyzed so as to demonstrate that the mechanical behavior of the outer tank under the long-period ground motion was good and within the controllable range.Finally,a new parallel isolation device consisting of the laminated rubber isolation bearing and the mild steel damper was introduced to study the influence of the long-period ground motion on the base isolation performance of the outer tank.The results proved that the effect of the long-period ground motion must be considered in the base isolation design of the outer tank because of their strong randomness,ambiguity,and uncertainty.The isolation device was effective for the short-period ground motion,but invalid for the long-period ground motion.When the predominant period of Mexican ground motion was close to the base isolation period,resonance phenomenon occurs in the outer tank,the horizontal displacement of the vertex was 2.74 times than that of El Centro ground motion,the base shear was 7.31 times than that of El Centro ground motion,and the displacement of base isolation system reached 385.49 mm.Therefore,it provides technological support and theoretical basis for the design of the outer tank.
作者
林树潮
周一君
Lin Shuchao;Zhou Yijun(Xijing University,Xi'an 710123,China Shaanxi Key Laboratory of Safety and Durability of Concrete Structures,Xi'an 710123,China;Post-doctoral Mobile Station of Civil Engineering,School of Civil Engineering,Tianjin University,300072,China;College of Civil and Architectural Engineering,North China University of Science and Technology,Tangshan 063210,China)
出处
《特种结构》
2021年第2期34-41,共8页
Special Structures
基金
唐山市重点研发计划项目(19150232E)
河北省省属高校基本科研业务费(JQN2020027)。
关键词
LNG
储罐
长周期地震动
双线性滞回特性
基础隔震
有限元分析
LNG storage tank
Long-period ground motion
Bilinear hysteretic characteristic
Base isolation
Finite element analysis
