Dynamic response characteristics of super high-rise buildings subjected to long-period ground motions

Spectrum characteristics of different types of seismic waves and dynamic response characteristics of super high-rise building structures under long-period ground motions were comparatively analyzed. First, the ground response wave （named LS-R wave） of a soft soil site with deep deposit, taking long-period bedrock seismic record as input, was calculated by wave propagation method. After that, a TOMAKOMAI station long-period seismic record from the Tokachi-Oki earthquake and conventional E1-Centro wave were also chosen. Spectrum characteristics of these waves were analyzed and compared. Then, a series of shaking table tests were performed on a 1：50 scale super high-rise structural model under these seismic waves. Furthermore, numerical simulation of the prototype structure under these excitations was conducted, and structure damages under different intensive ground motions were discussed. The results show that： 1） Spectrum characteristics of ground response wave are significantly influenced by soft soil site with deep deposit, and the predominant period has an increasing trend. 2） The maximum acceleration amplification factor of the structure under the TOM wave is two times that under the E1-Centro wave; while the maximum displacement response of the structure under the TOM wave is 4.4 times that under the E1-Centro wave. Long-period ground motions show greater influences on displacement responses than acceleration responses for super high-rise building structures. 3） Most inelastic damage occurs at the upper 1/3 part of the super high-rise building when subjected to long-period ground motions.

Effects of high modes on the wind-induced response of super high-rise buildings

For super high-rise buildings, the vibration period of the basic mode is several seconds, and it is very close to the period of the fluctuating wind. The damping of super high-rise buildings is low, so super high-rise buildings are very sensitive to fluctuating wind. The wind load is one of the key loads in the design of super high-rise buildings. It is known that only the basic mode is needed in the wind-response analysis of tall buildings. However, for super high-rise buildings, especially for the acceleration response, because of the frequency amplification of the high modes, the high modes and the mode coupling may need to be considered. Three typical super high-rise projects with the SMPSS in wind tunnel tests and the random vibration theory method were used to analyze the effect of high modes on the wind-induced response. The conclusions can be drawn as follows. First, for the displacement response, the basic mode is dominant, and the high modes can be neglected. Second, for the acceleration response, the high modes and the mode coupling should be considered. Lastly, the strain energy of modes can only give the vibration energy distribution of the high-rise building, and it cannot describe the local wind-induced vibration of high-rise buildings, especially for the top acceleration response.

Discussion on the Construction of Anti-smoke Construction Technology in Super High-rise Buildings

In recent years with the increasing number of super high-rise buildings and the ever-expanding scale the anti-smoke construction technology has attracted more and more attention.Based on this situation,this paper analyzes the smoke control technology of super high-rise buildings.The paper analyzes the importance of the application of anti-smoke construction technology in super high-rise buildings,analyzes the problems in the construction of smoke control and super high-rise buildings.The anti-smoke construction technology was studied and I hope that it can benefit the application of anti-smoke construction technology in high-rise buildings.

Collapse simulation of a super high-rise building subjected to extremely strong earthquakes

In recent years, super high-rise buildings (>500 m) are developing very quickly and become an important frontier of civil engineering. The collapse resistance of super high-rise buildings subjected to extremely strong earthquake is a critical problem that must be intensively studied. This paper builds up a nonlinear finite element model of the tallest building in China, Shang- hai Tower (632 m), and proposes the modeling method and failure criteria for different structural elements. The dynamic char- acters of this building are then analyzed, and the possible failure modes and collapse processes due to earthquakes are pre- dicted, as well as the corresponding collapse mechanism. This work will be helpful in collapse prevention and the seismic design of super high-rise buildings.

An improved ground motion intensity measure for super high-rise buildings

Ground motion intensity measure (IM) is an important part in performance-based seismic design. A reasonable and efficient IM can make the prediction of the structural seismic responses more accurate. Therefore, a more reasonable IM for super high-rise buildings is proposed in this paper. This IM takes into account the significant characteristic that higher-order vibration modes play important roles in the seismic response of super high-rise buildings, as well as the advantages of some existing IMs. The key parameter of the proposed IM is calibrated using a series of time-history analyses. The collapse simulations of two super high-rise buildings are used to discuss the suitability of the proposed IM and some other existing IMs. The results indicate that the proposed IM yields a smaller coefficient of variation for the critical collapse status than other existing IMs and performs well in reflecting the contribution of higher-order vibration modes to the structural response. Hence, the proposed IM is more applicable to seismic design for super high-rise buildings than other IMs.

某大底盘多塔超高层结构分析与设计

某项目为1栋带3座塔楼的大底盘多塔超高层结构,塔楼均匀分布于裙房北侧,分别为部分框支剪力墙和剪力墙结构体系。针对塔楼偏置问题进行了分析,并采用盈建科、PERFORM3D、ETABS等软件对结构进行了多塔模型和单塔模型的整体计算对比、罕遇地震下的动力弹塑性分析及温度效应分析。多塔与单塔模型整体指标吻合较好,内力接近,同时根据分析结果对结构构件采取相应的构造加强以满足性能目标。结果表明,项目结构形式及构件截面合理,具有良好的抗震性能。

深圳某超高层结构设计重点及难点分析

深圳某超B级高度的超高层塔楼,采用钢管混凝土框架柱+钢筋混凝土框架梁+钢筋混凝土核心筒结构。塔楼相对于裙房部分有较大的偏心,同时因为建筑功能要求存在有多处跃层透空空间。采用盈建科、ETABS等软件对项目进行了整体计算、构件设计及楼板应力分析。针对塔楼偏置、楼板不连续、核心筒收进等不规则项,对于结构构件采取适当的构造加强,以满足抗震性能目标。对于外框梁不闭合的问题,采取对比分析,确保水平地震剪力可有效传递。结果表明,项目结构体系选择恰当,结构布置、构件截面取值合理,具有良好的抗震性能。

昆明时代广场超限高层建筑结构设计

昆明时代广场地下3层,地上28层,总高度97.9m,采用框支剪力墙结构体系,属B类高度结构,同时具有高位转换、大底盘多塔等复杂超限情况,文中介绍其结构布置和选型、结构抗震性能化设计目标、结构静力推覆(Pushover)和整体计算分析等,并针对结构特点,结合超限审查专家的意见,介绍设计中采取的针对性措施,可供类似工程结构设计参考。

超高层建筑裙房钢结构工程综合施工技术

以某超高层建筑裙房的钢结构施工为例,围绕钢结构安装、狭小空间内的塔吊布置以及钢结构幕墙屋面施工技术,对裙房钢结构工程综合施工工艺进行了介绍。有限元分析结果显示,在专业一体化管理的指导下,施工完成后的钢结构最大应力和最大变形均符合相关要求,可为今后超高层建筑裙房钢结构施工提供技术手段和参考。

广州光大橡园结构设计

广州光大橡园是一个带转换层的多塔楼大底盘高层建筑,地下室单层建筑面积达33000m2,文中重点介绍该项目地基基础、抗浮、超长混凝土结构以及转换层设计等几个关键环节,供同行参考。

水平力作用下塔楼与裙房楼层剪力传递分析

通过结构模态分析、水平力作用下裙房与塔楼连体位置内力应力分析,探讨了裙房与塔楼连接区域实际工作性能,并根据双塔大底盘结果提出了构造加强措施,为今后类似工程的施工提供了参考依据。

合肥华润中心动力弹塑性分析

以合肥华润中心为例,采用Perform3D软件对结构进行了罕遇地震下弹塑性分析,并检验了结构抗震安全性,计算结果显示结构具有较好的弹塑性工作性能,满足大震不倒的设防要求。

广西某高层综合楼结构受力分析与加强措施

为了确保不规则超限高层建筑结构的抗震安全性能,对广西某新建综合楼进行了结构受力分析与相应的加强措施。综合楼采用钢筋混凝土框架剪力墙结构体系,结构存在扭转不规则、楼板不连续、塔楼偏置、穿层柱等不规则问题,属于特别不规则超限高层建筑。利用YJK、Midas等软件对主体结构进行了反应谱、弹性时程、楼板应力、弹塑性时程和裙房大跨度梁受力等分析,结构各项指标的计算结果均满足受力以及规范要求,确保了结构具有良好的抗震性能。

广州东方文德广场超限高层设计

广州东方文德广场由A～D共4幢住宅塔楼和E幢办公塔楼组成,塔楼最大高度119.3m。本工程存在平面不规则、竖向不规则、错层、大底盘多塔楼和高位转换等超限情况,属于复杂高层建筑结构。结构设计时从抗震概念设计出发,适当提高结构抗震性能目标,采用不同的计算软件进行结构分析,采取有针对性的构造加强措施,从而确保了结构的抗震安全性。

小底盘高裙房双塔超高层结构单塔模型选择方法

由于各塔楼之间的扭转耦联,小底盘高裙房双塔楼结构表现出复杂的结构特性。根据整体模型计算的自振周期,很难判断具体属于哪个塔楼。为控制周期比,需要建立多个单塔模型来验算周期比,单塔模型的剖分应使其计算的位移、内力与整体模型计算结果尽量一致。以某实际工程为例,提出了小底盘高裙房双塔结构单塔模型的剖分方法,对3个计算模型进行结构静力弹性分析,比较了各模型的自振周期、位移比、剪重比和刚重比,得出一些有益的结论,可为类似工程的设计提供借鉴。

合肥华润中心超限结构设计要点

合肥华润中心结构设置一道防震缝兼作伸缩缝,将整体结构分成北部大底盘双塔及南部裙房两个部分。主要针对北部大底盘双塔部分的结构设计进行阐述。通过大底盘双塔结构及单塔结构两种模型的分析比较,得到塔楼的主要性能、塔楼及裙房地震剪力的传递规律;进行了全过程的施工模拟,考察超长结构温度效应及加强措施;针对塔楼跨层柱进行了屈曲分析,保证跨层柱的稳定性;对塔楼墙转柱区域进行了精细的有限元计算分析,保证转换区域结构的安全性。