叶昆, 张子翔, 朱宏平. 近场地震竖向分量对LRB基础隔震结构地震响应影响分析[J]. 工程力学, 2016, 33(4): 49-57. DOI: 10.6052/j.issn.1000-4750.2014.04.0315
引用本文: 叶昆, 张子翔, 朱宏平. 近场地震竖向分量对LRB基础隔震结构地震响应影响分析[J]. 工程力学, 2016, 33(4): 49-57. DOI: 10.6052/j.issn.1000-4750.2014.04.0315
YE Kun, ZHANG Zi-xiang, ZHU Hong-ping. INFLUENCE OF NEAR-FIELD VERTICAL GROUND MOTIONS ON THE SEISMIC RESPONSE OF LRB BASE-ISOLATED STRUCTURES[J]. Engineering Mechanics, 2016, 33(4): 49-57. DOI: 10.6052/j.issn.1000-4750.2014.04.0315
Citation: YE Kun, ZHANG Zi-xiang, ZHU Hong-ping. INFLUENCE OF NEAR-FIELD VERTICAL GROUND MOTIONS ON THE SEISMIC RESPONSE OF LRB BASE-ISOLATED STRUCTURES[J]. Engineering Mechanics, 2016, 33(4): 49-57. DOI: 10.6052/j.issn.1000-4750.2014.04.0315

近场地震竖向分量对LRB基础隔震结构地震响应影响分析

INFLUENCE OF NEAR-FIELD VERTICAL GROUND MOTIONS ON THE SEISMIC RESPONSE OF LRB BASE-ISOLATED STRUCTURES

  • 摘要: 该文主要对比分析了近场区竖向地震动对LRB基础结构动力响应的影响。首先,在ABAQUS有限元软件中建立了较为精确的有限元模型:上部结构采用纤维模型以考虑隔震结构在近场地震作用下可能出现的塑性变形,隔震层采用能反映隔震支座水平和竖向力学性能相互耦联的"Ryan-Kelly"力学模型;同时,综合考虑隔震支座的剪切破坏和拉压破坏以确定支座的破坏界限;在此基础上,分别进行隔震结构在水平地震单独作用和水平竖向地震联合作用下的动力分析,对比分析结果可知:近场区竖向地震动对于隔震支座的破坏模式影响较大,在较大的竖向分量作用下,隔震支座可能会在剪切破坏之前先发生拉压破坏;对于上部结构的动力响应,竖向地震动的影响具有随机性,但同样不可忽略,在某些工况下,考虑竖向地震作用会较大幅度地降低其水平动力响应。

     

    Abstract: This paper mainly concerns the influence of near-field vertical ground motions on the seismic response of base-isolated structures equipped with lead rubber bearings. Firstly, a relatively precise finite-element model was presented in ABAQUS finite element software. The fiber model was adopted to simulate the superstructure as plastic deformation may occur under the near-field ground motion, and the "Ryan-Kelly" mechanical model was introduced into the software as a user-defined element to consider the coupling effects between the horizontal and vertical mechanical behavior of the bearings. Moreover, to analyze the influence of near-field vertical ground motion on the failure mode of the bearings, a failure boundary was determined by comprehensively considering the maximum horizontal displacement, the buckling limit under pressure and the maximum tensile stress of the bearings. A comparative study based on the model was conducted to analyze the influence of near-field vertical ground motions on the seismic response of base-isolated structures. The results show that the vertical ground motion significantly affects the failure mode of the bearings and may cause the bearings to buckle under pressure or to be damaged under tension before they exceed the horizontal displacement limit. The results also show that in some cases, the seismic response of the superstructure is reduced when the vertical ground motion is taken into consideration.

     

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