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.

高位转换超高层住宅动力弹塑性时程分析实例

洲头咀A7栋楼为高位转换的超限高层。本文基于梁柱塑性铰和剪力墙纤维模型,利用MIDAS Buliding软件实现了超高层建筑结构的弹塑性时程分析,验证结构是否满足"大震不倒"的设防水准要求。研究了在大震作用下结构将出现的破坏模式、塑性发展特点等,寻找结构薄弱部位和薄弱构件,提出相应的加强措施。计算结果表明,在给定地震波的罕遇地震作用下,结构整体受力性能良好,能满足罕遇地震下的抗震性能目标。

洲头咀A5、A6、A7栋超限高层结构抗震设计

洲头咀A5、A6、A7栋楼为一大底盘多塔带高位转换的超限高层。本文主要对其结构布置、抗震计算分析及结构概念设计等方面进行了介绍。针对其多塔高位转换这一主要超限特点,采用了基于性能的抗震设计。经多模型、多软件的比较分析及弹性、弹塑性补充计算,保证设计能够覆盖结构的各种实际受力状态。对结构的薄弱部位采取增强配筋,以及设置钢骨梁、柱等特殊构造措施,使结构的抗震性能满足规范及性能目标的要求。