【作者】 王栋；

【导师】 杜永峰； 黄锐；

【作者基本信息】 兰州理工大学 ， 建筑与土木工程（专业学位）， 2021， 硕士

【摘要】 塔楼偏置高层建筑结构,由于同时存在结构沿竖向收进后的刚度突变及结构质心与刚心不重合形成偏心两种结构布置不规则的情况,在水平地震作用激励下,两种不规则情况相互影响,结构受力复杂且不易预测薄弱部位,在地震作用下容易使结构形成较大震害,造成结构整体或局部倒塌,也对结构设计造成较大难度。本课题结合某塔楼偏置复杂高层建筑结构工程案例,项目位于设防烈度8度(0.2g)地区,地上24层,带5层裙房,房屋高度89.50m,采用框架-剪力墙结构。首先按传统抗震结构与按采用基础隔震技术的隔震结构的两种方法完成结构设计,针对该塔楼偏置抗震结构所特有的不利动力响应,当采用基础隔震技术后的显著变化进行了分析比较,得出了隔震结构扭转因子明显小于抗震结构、振动变形明显集中于隔震层、结构响应以平动为主、前2～3阶振型对底部剪力贡献较大,高阶振型对底部剪力的影响较小、采用隔震技术后楼层扭矩折减系数小于剪力折减系数等结论。对上述两种实际的设计模型进行了罕遇地震作用下的弹塑性分析,对比了大震下结构整体抗震性能及主要抗侧力构件的损伤,得出了在满足同等外部条件及规范要求的前提下,隔震结构主要抗侧力构件的损伤明显小于抗震结构,采用隔震技术可有效提高该类复杂结构抗震性能,减轻结构关键部位的损伤。分析了基础隔震塔楼偏置复杂高层建筑结构采用设缝方案与连体方案时,两种方案在罕遇地震下抗倾覆性能的差异,得出采用连体方案时对高层主塔的整体抗倾覆安全度高于设缝方案的结论。针对塔楼偏置复杂高层建筑结构所特有的主裙楼差异沉降变形、后浇带设置及其对支座轴力、结构内力的影响进行了分析与讨论,得出了高层基础隔震建筑当纵向长度较大、地基压缩性较高时,应考虑基础不均匀沉降对支座轴力的不利影响,沿纵向两端部的支座配置时宜适当加大截面;在隔震层屈服承载力抗风验算时应考虑横向倾斜沉降引起的支座附加水平力;应该合理考虑沉降后浇带的设置及施工模拟计算,减小主裙楼差异沉降对两侧结构附加内力的影响,当未设置后浇带或提前封闭后浇带时,应进行详尽的分析,保证支座的受压与受拉承载力满足要求等结论。最后以该工程实例为研究对象,对比分析了单塔塔楼偏置隔震结构、考虑基础沉降的单塔塔楼偏置隔震结构、施工模拟考虑沉降后浇带的单塔塔楼偏置隔震结构三种模型在极罕遇地震作用下发生侧向增量倒塌的概率,定量评估了不同情况下单塔塔楼偏置隔震结构的抗倒塌能力,结果表明考虑基础整体倾斜沉降的单塔塔楼偏置隔震结构的损伤指数和失效概率均明显高于未考虑基础沉降影响的单塔塔楼偏置隔震结构。本课题研究得出的结论,可为同类工程的设计提供借鉴。更多还原

【Abstract】 The high-rise building structure with offset tower become a special structural system.Due to the sudden change in stiffness after the structure is retracted in the vertical direction and the non-coincidence of the mass center and the stiffness center of the structure,there are two types of irregularities in the layout of the eccentric structure.The two irregular situations affect each other under the excitation of horizontal earthquakes,so the structural forces are c omplicated and the weak parts are difficult to predict.Under the action of earthquakes,it is easy to cause the structure to form greater seismic damage,cause the structure to collapse in whole or in part,and also cause great difficulty in the structura l design.This subject combines a complex high-rise building structure engineering with a tower offset.The project locates in an area with a fortification intensity of 8 degrees(0.2g),24 floors above the ground,with a 5-story podium,the height of the building is89.50 m,and the frame shear wall structure is adopted.Fir st,the structure design is completed by the two methods of traditional seismic structure and seismic isolation structure.According to the unique adverse dynamic response of the seismi c structure with the tower offsetting,the significant changes after us ing the base isolation technology are analyzed and compared.It is concluded that the torsional factor of the seismic isolation structure is significantly smaller than that of the seism ic structure,the vibration deformation is concentrated on the isolatio n layer,the structural response is mainly translational,the first 2～3 vibration modes have a greater contribution to the bottom shear force,the higher modes have less impact on the bottom shear,and the floor torque reduction coefficient is smaller than the shear force reduction coefficient after adopting the seismic isolation technology.The elastic-plastic analysis of the above two practical design models under rare earthquakes is carried out,and the overall seismic performance of the structure and the damage of the main lateral force resisting members under large earthquakes are compared.The analysis shows that the damage of the main lateral force resisting members of the seismic isolation structure is significantly less than that of the seismic structure on the premise of meeting the same external conditions and code requirements.The seismic isolation technology can effectively improve the seismic performance of this kind of complex structure and reduce the damage of the key parts.The difference in the anti-overturning performance of the two schemes under rare earthquakes when the joint scheme and the jointed scheme are adopted for the complex high-rise seismic isolation structure with offset tower was analyzed in this paper.The anti-overturning safety is higher than that of the joint scheme.When the bearings at both ends along the longitudinal direction are configured,the section should be appropriately increased.When checkin g the wind resistance of the yield-bearing capacity of the isolation la yer,the additional horizontal force of the bearing caused by transverse inclined settlement should be considered.The setting of the post-settlement pouring zone and the construction s imulation calculation should be considered to reduce the influence of t he differential settlement of the main podium on the additional internal forces of the structure on both sides.When the post-pouring zone is not set or closed in advance,detailed anal ysis should be carried out to ensure that the bearing capacity of the b earing meets the requirements and other conclusions.Finally,taking the engineering example as the research object,the probability of lateral incremental collapse of single tower offs etting isolation structure,single tower offsetting isolation structure considering foundation settlement,and single tower offsetting isolation structure considering post-cast strip settlement in construction simulation under extremely rare earthquake is compared and analyzed.The results show that the damage index and failure probability of the single tower offset isolation structure considering the overall inclined settlement of the foundation are significantly higher than that of the single tower offset isolation structure without considering the influence of foundation settlement.The conclusions drawn from the research of this subject can provide a reference for the design of similar projects.更多还原