The Structural Design of Tall and Special Buildings

Chen, Xin; Er, Guo‐Kang; Pan Iu, Vai

doi: 10.1002/tal.2075pmid: N/A

In this paper, the governing equations of the outrigger‐braced structure are formulated by considering the influence of core‐wall width. The axial forces in the columns are considered as unknowns and the compatibility of the column's axial deformation is considered in formulating the governing equations. Then, the governing equations for the optimum locations of outriggers are formulated by minimizing the top drift of central core wall. After that, the influence of core‐wall width on the optimum outrigger locations, the drift‐reduction efficiency and moment‐reduction efficiency is investigated numerically. Some results are presented for the reference in the preliminary design of the outrigger‐braced structures.

doi: 10.1002/tal.2026pmid: N/A

No abstract is available for this article.

Zhou, Ying; Chen, Qidong; Wu, Hao; Wen, Hongchang; Nong, Xingzhong; Wu, Yongsheng; Xiao, Peng

doi: 10.1002/tal.2098pmid: N/A

This research deals with a frame‐supported shear wall for urban over‐track building of vehicle depot in Chisha, Guangzhou, China, which is characterized by its remarkable height of 160.8 m. Technical issues are commonly encountered in these kinds of buildings due to discontinuous vertical structural rigidity, large podium, and structural transition. These challenges significantly impact the engineering process, especially when the rigidity difference between transfer story exceeding the threefold, as well as the building height exceeds limit as in code. In this paper, a shaking table test was developed based on a 1:10 scaled model of the structure. Using similarity theory, the dynamic similarity relationship was established for the design of the model. Subsequently, the experimental model was constructed with the configuration of critical parameters such as mass design, sensor placement, and seismic test conditions. This was followed by in‐depth analysis, recording component failures and investigating key aspects such as dynamic characteristics, that is, acceleration and displacement responses and shear force distribution under different earthquake intensities. A theoretical seismic response of the prototype structure was derived from the test results. The shaking table tests confirmed that the structure met the stringent seismic design requirements as prescribed in the Chinese standards, with no damage under minor earthquakes, repairability under moderate earthquakes, and collapse prevention under rare earthquakes. The results of the study provide valuable insights along with improvement measures for the design and development of similar urban over‐track buildings, potentially contributing to more efficient land use in urban China.

Sun, Mengmeng; Li, Qiusheng

doi: 10.1002/tal.2102pmid: N/A

In operational modal analysis (OMA), only structural responses are typically available. In this context, bias and variance (uncertainty) errors may exist in modal estimates (especially damping estimates), resulting in inaccurate determination of the modal properties of large‐scale structures under harsh excitations. To this end, a hybrid OMA framework based on the modal decoupling, the natural excitation technique, the random decrement technique (RDT), and improved eigensystem realization algorithm (ERA) with the automated stabilization diagram is presented to perform high‐accuracy modal estimates with uncertainty quantification for large‐scale structures under normal and severe ambient excitations. The accuracy and effectiveness of the hybrid framework for identifying the modal parameters are validated by numerical simulation study of a framework structural model. Furthermore, the hybrid framework is applied to analyze recorded acceleration responses of a supertall building with 600‐m height under normal excitations and typhoon condition to verify its applicability in field measurements. The numerical simulation and field measurement studies demonstrate that the hybrid framework can not only perform precise modal estimations with uncertainty quantification through a single ambient vibration measurement but also effectively reveal the variations of modal properties of supertall structures under harsh excitations from multiple perspectives. This paper aims to enhance the reliability and accuracy of modal estimation for engineering structures and further provide insight into the variations of dynamic properties of large‐scale civil structures under severe excitations.

Xu, Qiang; Xu, Liping; Meng, Linghui; Liu, Yuyang; Bai, Yinhui

doi: 10.1002/tal.2096pmid: N/A

In order to study the dynamic characteristics and human‐induced vibration response of light steel foamed concrete composite floor (LCSF), the vibration characteristics of 4.2 m × 5 m LCSF model were tested under the condition of opposite side support, and the natural vibration frequency of LCSF was obtained. The orthogonal anisotropic elastic plate and the simulated beam element were used, respectively, to compute the natural vibration frequency of the LCSF, and the estimated findings were compared with those obtained from measurements. The discrepancy between the calculated results and the measured results of the approximate beam element using the natural vibration frequency calculation technique is around 13%, but the error for the plate element using the calculated results and the tested results is about 23%. To examine the floor's vibration response under the factors of step frequency, walking path, pedestrian density, and load distribution, the LCSF underwent a human‐induced vibration test. The test results show that the fundamental frequency of the LCSF specimen is about 11 Hz, which can meet the requirements of the specification. However, the vibration response of the LCSF specimen under different conditions of pedestrian load is significantly different. With the acceleration of step frequency and the increase and concentration of load, the floor's vibration response becomes more visible. In the route test, it is established that LCSF has the attribute of a unidirectional plate. The natural vibration frequency of similar floor slab can be calculated by the method of simulating the natural vibration frequency of beam element. The findings can serve as a guide for LCSF research and implementation.