软土场地大型LNG储罐组合滑移隔震

Combined sliding seismic isolation of large LNG storage tank in soft site

针对建设在沿海软土场地上的大型液化天然气(LNG)储罐面临隔震困难的问题,本文提出了一种可复位、耗能、抵抗大变形的新型隔震方案,并研发了相应的带有阻尼器反力墙的组合隔震层。为了验证新型组合滑移隔震方案的控制效果,以外罐壁剪力、脉冲剪力、单桩剪力、晃动波高和隔震层水平变位为主要性能指标,分别对铅芯橡胶支座隔震储罐、复摩擦摆支座隔震储罐和组合隔震储罐在地震作用下的动力响应进行了对比分析。结果表明:在操作基准地震(OBE)作用下,上述3种隔震方案均有明显的隔震效果(晃动波高除外),但在安全停运地震(SSE)作用下,只有组合滑移隔震方案能够承受大震下隔震层产生的较大水平变位,而且组合滑移隔震对LNG储罐晃动波高在OBE及SSE地震作用下均有较好的控制效果。

Liquefied natural gas(LNG)storage tank belongs to urban lifeline project,adopting seismic isolation technology to ensure its seismic safety is the development trend in the future. but the seismic isolation is a problem faced by LNG storage tank built in the coastal soft site. To solve this problem,a new combined sliding isolation scheme,which can be self-centering,energy dissipation and resistance to large deformation is proposed,and a combined isolation layer with damper reaction wall is developed. In order to verify the control effect of the new combined sliding seismic isolation scheme,taking outer tank shearing force, impulse shearing force, single pile shearing force, sloshing wave height and the horizontal displacement of seismic isolation layer as the main performance indicators,the dynamic response of lead rubber bearing isolation tank, friction pendulum isolation tank and combined isolation tank under earthquake were analyzed and compared respectively. The results show that under the action of operating basis earthquake(OBE) earthquake,the above three isolation schemes all have obvious isolation effect(except sloshing wave height),but under the safe shutdown earthquake(SSE) earthquake,only the combined sliding seismic isolation scheme can resist the large horizontal displacement of the isolation layer under large earthquake,and it has better control effect on the sloshing wave height of the LNG storage tank both under OBE and SSE earthquakes.