多重灾害下带组合控制伸臂桁架超高层结构受力机理与设计理论

Damped outriggers of super-tall buildings, which induce dampers to outriggers, can well dissipate the energy input to the structures. However, damped outriggers adopt the single type of displacement-dependent (DD) outrigger or velocity-dependent (VD) outrigger, which cannot simultaneously achieve the optimal control effect under multiple hazards like earthquake and wind. Combined control outriggers, which combined both DD and VD outriggers according to the engineering demands under multiple hazards, are proposed in this project. By use of combined control outriggers, the aim of this project is to control the dynamic responses of super-tall buildings under dynamic hazards. This project will start from building a 600-meter-tall typical super-tall building benchmark with multiple outriggers. The sub-structure experiments on DD and VD outriggers from the benchmark will be tested and the parameters of the damped outriggers are identified. Introduced the identified parameters of outriggers, the refined analytical model of the benchmark will be built and, under earthquake and wind excitations, parameter analysis of the benchmark with combined control outriggers will be performed. The working mechanism of combined control outriggers is studied to put forward the optimal distribution of combined control outriggers for super-tall buildings. The control effect of combined control outriggers will be investigated through shaking table test and numerical wind tunnel test. With the verified effect, the relationship between elasto-plastic displacement demands of super-tall buildings and performance parameters of combined control outriggers will be built. And, the performance-based design method of the super-tall buildings with combined control outriggers will be proposed. This project forms the fundamental basis to realize the resilience of 600-meter-tall super-tall buildings under multiple hazards.

消能减震伸臂桁架通过在超高层结构伸臂桁架中引入阻尼器，更好地耗散结构输入能量。然而，目前消能减震伸臂桁架采用单一的位移相关型伸臂桁架或速度相关型伸臂桁架，无法同时达到地震和风荷载等多重灾害作用下的响应控制最优。本项目提出组合控制伸臂桁架，即根据多重灾害作用需求设置伸臂桁架，以实现对超高层结构动力灾变的综合控制。拟针对600米级典型超高层基准结构，实施位移相关型和速度相关型伸臂桁架子结构试验，识别子结构力学参数；建立带组合控制伸臂桁架超高层基准结构精细化模型，变参数研究地震和风多重灾害作用下受力机理，建立组合控制伸臂桁架最优布置方程；通过模拟地震振动台试验和数值风洞试验，验证组合控制伸臂桁架超高层结构振动控制效果；采用增量动力分析法，建立超高层结构弹塑性位移需求与组合控制伸臂桁架体系的性能关系，建立结构基于性能的设计方法。本项目将为实现多重灾害下600米级超高层结构的可恢复功能做出基础研究。

对伸臂桁架结构系统的研究一般从普通伸臂桁架到单一消能减震伸臂桁架，而对于组合消能减震伸臂桁架结构系统的研究较少；研究中地震作用和风荷载往往单独研究，而关于这两种甚至更多种灾害共同作用下组合消能减震伸臂桁架结构系统的作用机理和优化设计的研究未开展。因此，本课题针对以上问题重点展开了多重灾害下组合控制伸臂桁架超高层结构的最优化抗震性能研究：提出了不同类型伸臂桁架结构系统时域内的数值简化模型；研究了消能减震伸臂桁架结构系统中阻尼器加载制度；分析了多重灾害下伸臂桁架超高层结构抗震性能；并提出多重灾害下不同类型伸臂桁架结构系统频域模型。本项目所提出的不同类型伸臂桁架结构系统多重灾害下的最优伸臂桁架位置和最优阻尼参数的概率模型或拟合表达式，可简洁且方便地应用于工程实际的方案设计中。工程结构在地震与风荷载耦合作用下的动力反应和易损性均大于单种灾害的作用，并且两者的耦合作用与地震和风的相对强度有着密切的关联，对于风敏感性较强的超高层建筑结构应开展多重灾害耦合作用分析，确保其安全性，避免相应的经济损失。