考虑SSI效应的立式储罐水平基础隔震研究

Seismic response of vertical storage tanks with horizontal base isolation considering soil-structure interaction(SSI)

立式储罐在地震作用下破坏严重,损失较大。为了降低立式储罐在水平地震激励下的地震响应,考虑土与结构相互作用对储罐地震响应的影响,将立式储罐基础隔震体系简化为3质点5自由度力学模型。依据Ham ilton原理建立立式储罐基础隔震体系的控制方程,给出了立式储罐基底剪力、倾覆弯矩、晃动波高和应力的理论表达。选取150 000m3储罐,采用W ilson-θ法对其进行了地震动响应分析。结果表明:储罐基础隔震体系能够降低储罐的地震响应;为获得理想的地震响应,场地、隔震周期和阻尼比存在优化取值区间;储罐抗震与减震设计要视设计安全需要来决定是否考虑土与结构的相互作用。

The vertical storage tanks are usually seriously damaged in strong earthquakes.In order to reduce seismic response of the vertical storage tanks under horizontal strong earthquake,the isolation system of the storage tank is simplified as a 3-mass 5-degrees-of-freedom model with considering soil-structure interaction.The governing equation is established based on Hamilton principle,and theoretical expressions of the base shear,overturning moment and stress are given.Seismic response analysis of a 150 000m3 storage tank is carried out with the Wilson-θ method.The results show that storage tank with the base isolation system could reduce the seismic response.It should be necessary to take the best site and optimal values of isolation period and damping ratio into account.Seismic and isolation design of storage tanks depends on design safety needs to decide on whether to consider soil-structural interaction.