村镇滑移隔震建筑瞬时输入能量的参数敏感性分析

Parameter sensitivity analysis of the instantaneous earthquake input energy for rural building structures supported on sliding base-isolation systems

以村镇建筑为研究对象,以滑移隔震结构的瞬时输入能量为响应指标,采用正交试验的方法对比分析了刚度比、隔震层第二阶段刚度系数、隔震层限位装置的屈服位移、隔震层摩擦系数、系统质量比和上部结构自振周期等6个参数对系统瞬时输入能量的敏感程度及影响规律,探寻对系统隔震效果最有利的参数取值,以期对村镇滑移隔震结构的设计应用提供一定的理论支持。结果表明:瞬时输入能量对本文所研究的系统参数的敏感性均与地震动的幅值和场地条件有关;在本文所考虑的参数范围内,上部结构自振周期对瞬时输入能量的影响最为显著,隔震层摩擦系数对瞬时输入能量的影响不显著;质量比对瞬时输入能量的影响与场地条件有关,在该参数大约取值为15时瞬时输入能量可以取到一个较小值,而当该参数大约取值为20时,瞬时输入能量可以取到一个较大值;隔震层限位装置的屈服位移对瞬时输入能量影响较为显著,但无明显规律可循,在该参数取值大约为0.006m或0.015m时,瞬时输入能量均可取到较小值;刚度比和第二阶段刚度系数总得来讲对瞬时输入能量的影响不显著。

Taking the stiffness ratio,the post-yield stiffness coefficient,the yield displacement of the limit device for isolation layer,the friction coefficient,the mass ration and the natural period of the superstructures as the influencing factores,sensitivity degree and influence law of the instaneous earthquake input energy is carried out for rural building structures supported on sliding base-isolation system in order to explore the parameter value that are most favorable to the seismic effect and provide certain theoretical support for the design and application of rural building structures supported on sliding base-isolation system.In the analysis,the orthogonal experiment method is adopted,and the instaneous earthquake input energy is treated as the only response index.The present study shows that the sensitivity of the instaneous earthquake input energy to the above parameters always depends on the amplitudes of earthquake motions and the engineering site conditions.The natural period of the superstructure exhibits a demonstrable effect on the instaneous earthquake input energy,while the friction coefficient of the isolation layer has no significant effect on it in the whole parameters range of concern.The effect of the mass ratio on the instaneous earthquake input energy is related to the engineering site conditions,and the instaneous earthquake input energy can achieve a smaller value when the mass ration is about 15,but it can get a bigger one when the mass ratio is about 20.The yield displacement of the limit device for isolation layer has a significant influence on the instaneous earthquake input energy,but there is no obvious rule to follow,and the instaneous earthquake input energy can achieve a smaller value when the yield dispalcement of the isolation layer is about 0. 006 m or 0. 015 m.It is also discovered that the stiffness ratio and the post-yield stiffness coefficent have ralatively weak effect on the instaneous earthquake input energy.