The Structural Design of Tall and Special Buildings

Li, Bo; Han, Zhen; Zhang, Xinxin; Yang, Qingshan; Li, Chen; Sun, Lin

doi: 10.1002/tal.2056pmid: N/A

Atmospheric flow is the main factor affecting the wind load of urban buildings. The measured data observed continuously from the 325‐m‐tall Beijing Meteorological Tower (BMT) during 2013–2017 is employed to investigate the vertically‐layered structure and surface roughness parameters of the urban boundary layer. Based on the local similarity theory and analysis results of the atmospheric stability and local friction velocity, it can be determined that the height of 80 m is near the bottom of the inertial sub‐layer, the range below this height belongs to the roughness sub‐layer, 140 m belongs to the inertial sub‐layer, and 200 m and 280 m are in the mixing layer. The local friction velocity at 80 m can be considered a relatively reliable value as the friction velocity. Moreover, seasonal effect on local friction velocity is minimal. According to the fitting result of near‐neutral strong wind samples by the log‐law, it is concluded that to obtain a more accurate wind speed profile, all layers should be included when picking fitting heights. In addition, surface roughness parameters are affected by the wind direction and speed. The variation according to the wind direction corresponds to the topographical distribution surrounding the BMT, and the higher range of wind speed may be more applicable for estimating surface roughness parameters.

Zheng, Tiancai; Ge, Qi; Xiong, Feng; Li, Guo; Xue, Yu; Deng, Xiang

doi: 10.1002/tal.2065pmid: N/A

This study investigates the flexural performance and degree of composite action (DCA) of precast concrete sandwich panels (PCSPs) with four types of connectors. Five full‐scale specimens were designed, and 4‐point bending tests were performed. The specimens included four PCSPs utilizing glass fiber reinforced polymer (GFRP) truss connectors, steel truss connectors, concrete rib connectors, and GFRP pin connectors, respectively, along with a solid panel (SP). The results indicated that the flexural performance and DCA provided by the four types of connectors followed an ascending order as follows: GFRP pin‐type connectors, GFRP truss connectors, steel truss connectors, and concrete rib‐type connectors. Moreover, the study presented a novel method for calculating DCA, namely, the neutral axis method, which was compared with the displacement and strain methods. The reasonableness and accuracy of the neutral axis method in calculating DCA during the linear elastic stage were verified. Results indicated that the neutral axis method provided more precise and reasonable DCA that closely matched the experimental results compared with the displacement and strain methods. Additionally, the neutral axis method was simpler to calculate DCA and had a broader range of applications. Finally, the study provided recommendations for the optimal application scenarios of each calculation method.

doi: 10.1002/tal.1966pmid: N/A

No abstract is available for this article.

Hamidia, Mohammadjavad; Jamshidian, Sara; Afzali, Mobinasadat; Safi, Mohammad

doi: 10.1002/tal.2062pmid: N/A

This paper presents a novel method for estimating the seismic peak interstory drift ratio (IDR) in reinforced concrete (RC) columns after an earthquake using surface crack image analysis. The quantitative representation of the complexity and irregularity of crack images in damaged RC columns is obtained through the consideration of the generalized fractal dimensions. The authors have compiled a comprehensive database consisting of 445 crack maps obtained from cyclic experiments conducted on 110 rectangular RC column specimens exhibiting double‐curvature deformation mode. This database is utilized by the authors to develop and validate the proposed procedure. The research database contains a wide range of structural and geometric features. Five closed‐form equations are developed with the objective of estimating the peak IDR experienced by the RC columns during a seismic event. The predictive equations are derived through the utilization of symbolic regression technique, with the input parameters varying according to the availability of columns characteristic parameters. Results reveal that generalized fractal dimensions, especially D−1, are strong vision‐based indicator of damage in RC columns having correlation coefficients with IDR ranging from 0.82 to 0.92 across the considered plans. The seismic peak IDR obtained through the empirical equations can serve as the input engineering demand parameter (EDP) in the seismic loss estimation frameworks. This allows for the determination of the probability of exceeding damage states for structural and nonstructural components of concrete buildings. Finally, the practical implementation of the methodology is examined by its application to an actual case of a damaged column during the Kermanshah earthquake of magnitude 7.3 that occurred in 2017.

Ocak, Ayla; Bekdaş, Gebrail; Nigdeli, Sinan Melih

doi: 10.1002/tal.2063pmid: N/A

Tuned liquid dampers provide structure control with the help of the liquid mass in tanks that are attached to the structure. The mass ratio affects the optimum tuned liquid damper (TLD) parameters. This study examines the effect of mass ratio on the control performance of TLD devices in providing seismic control of structures with different damping ratios. For this purpose, TLD devices with different mass ratios were placed on two different single‐story steel and reinforced concrete structure models, and their performance under earthquake excitation was investigated. TLD parameters for obtaining the optimum displacement level in the 0.5‐ and 1.0‐s structure natural period for both structure types were optimized with the Jaya algorithm (JA), which is a metaheuristic algorithm. By using the optimum TLD parameters, the structural displacement and total acceleration values were obtained by the critical earthquake analysis. When the results are examined, it is understood that TLD mass increase from a 20% mass ratio for both structure types and selected structure periods does not have a significant effect on TLD control performance.

Dong, Xiaohui; Tang, Zhenyun; Du, Xiuli

doi: 10.1002/tal.2055pmid: N/A

Real‐time hybrid simulation is a testing method that combines physical experiments and numerical simulations, which can increase the dimensions of experimental specimens and reduce the error of scaling testing. Currently, the maximum degrees of freedom of numerical models are 7000 in real time. To improve the scale of numerical simulation in real time, a testing framework based on Python and graphics processing unit was proposed in this paper. The maximum degrees of freedom of the numerical model exceeded 24,000 with the testing framework. The testing capacity of real‐time hybrid simulation was significantly improved by the graphics processing unit calculations.