The Structural Design of Tall and Special Buildings

Pinto‐Cruz, Mao Cristian

doi: 10.1002/tal.70070pmid: N/A

The current Brazilian standard NBR 6118, along with similar codes, evaluates global second‐order effects due to wind actions through a stability coefficient (α$$ \alpha $$) and an amplification factor (γz$$ {\gamma}_z $$), both of which require detailed structural modeling, incremental iterations, and significant computational cost. Given the significance of second‐order effects—which amplify internal forces, lateral displacements, and interstory drifts—this paper addresses both conceptual inconsistencies and computational burdens by proposing exact, closed‐form solutions for the calculation of the stability coefficient α$$ \alpha $$ and the amplification factor γz$$ {\gamma}_z $$. The proposed solutions are derived using the continuous method approach, modeling the structure as an equivalent continuous generalized sandwich‐type beam—an extension of the classical sandwich beam obtained by its serial coupling with a shear beam. This specific serial coupling allows for an accurate reproduction of the four fundamental deformation mechanisms: global bending, global shear, local bending, and local shear. First, an analytical expression is proposed for computing the stability coefficient α$$ \alpha $$, which modifies the classical equation by introducing a dimensionless parameter μ$$ \mu $$. This parameter accounts for the influence of the four deformation mechanisms and may either reduce or amplify the value proposed by the NBR 6118 code. Subsequently, two analytical expressions are proposed for computing the amplification factor γz$$ {\gamma}_z $$. The first is derived directly from a static analysis in which the second‐order moment is obtained through a series of incremental moment applications, loading the structure successively from its previously displaced configuration. The second is based on a dynamic analysis that relates second‐order effects to the fundamental period of the structure. The proposed analytical expressions enable the incorporation of second‐order effects through a single‐step first‐order analysis and are applicable to planar structural systems and regular symmetric buildings. Numerical applications show that the proposed expressions exhibit maximum errors of −6.26% for the stability coefficient α$$ \alpha $$ and +1.65% for the amplification factor γz$$ {\gamma}_z $$, confirming their reliability for safe and practical use in structural engineering analysis and design.

Yan, Feifei; Zhang, Jingke; Zhang, Lixiang; Xu, Hongsheng; Wang, Nan; Yan, Changgen

doi: 10.1002/tal.70107pmid: N/A

Inclined historic masonry towers are highly vulnerable to seismic forces due to the combined effects of material degradation and geometric nonlinearity, yet existing studies often neglect their interactions. This study develops a nonlinear finite element (FE) framework incorporating plastic damage constitutive laws to address this gap. The White Temple Tower (inclination angle 0.394°) is used as a case study, where a high‐fidelity 3D model is constructed and validated against empirical formulas, achieving an error margin below 5%. Key findings reveal that inclination amplifies seismic responses: under El Centro, Dingxi‐Minxian, and Lanzhou artificial waves, horizontal accelerations at the tower apex increased by 22%, 28%, and 13%, respectively, while vertical accelerations rose by 24%, 22%, and 11%. Displacement responses similarly escalated, with horizontal increments of 1.2, 1.7, and 0.4 mm, and vertical increments of 0.1, 0.1, and 0.04 mm. The acceleration amplification coefficient curves present a “C” shape, with the maximum horizontal acceleration amplification effect occurring at the top, while the vertical acceleration amplification coefficient is greatest at the base. This indicates that the vertical component should not be disregarded in seismic analysis. Damage evolution followed three distinct phases: (1) micro‐crack accumulation (PGA = 0.2 g, damage factor DF = 0.12), (2) localized spalling (PGA = 0.4 g, DF = 0.37), (3) global plastic failure (PGA = 0.6 g, DF = 0.9), with damage initiating within 2–3 s of seismic loading. Notably, small earthquakes (PGA = 0.2 g) produced acceleration amplifications 1.5 times greater than large earthquakes, emphasizing the critical role of low‐intensity seismic events in triggering early‐stage damage. Additionally, the Buddha niches, eave edges, as well as the top and bottom of the tower experience significant stress, serving as key criteria for prioritizing reinforcement interventions. This study advances the seismic resilience assessment of historic masonry towers by offering a systematic evaluation method and a replicable modeling framework.

Jafarpour, Sina; Zahrai, Seyed Mehdi; Asghari, Abazar

doi: 10.1002/tal.70106pmid: N/A

Tall telecommunication towers are highly vulnerable to seismic and wind‐induced vibrations due to their slender geometry, low damping, and long fundamental periods. Existing control systems often struggle to balance adaptability, energy efficiency, and real‐time feasibility. This study introduces a fully data‐driven semiactive control framework for the Milad Tower, integrating magnetorheological (MR) dampers modeled via artificial neural networks (ANNs) with four control strategies: linear quadratic regulator (LQR), fuzzy logic controller (FLC), model predictive controller (MPC), and adaptive neuro‐fuzzy inference system (ANFIS). The tower was subjected to 21 spectrally matched ground motions, categorized into near‐field with pulse, near‐field without pulse, and far‐field earthquakes, tailored to its long‐period dynamics using wavelet‐based spectral matching. Among all strategies, MPC achieved the greatest peak and RMS response reductions, lowering RMS displacement and acceleration by 73.3% and 40.3%, respectively, but required the highest control effort (60.9%). ANFIS matched or slightly exceeded MPC's performance while consuming less energy (54.6%) and demonstrated superior adaptability, especially under high‐pulse near‐field events by preventing control saturation. FLC consistently outperformed LQR but lagged behind ANFIS in adaptability. These results underscore the effectiveness of combining ANN‐based damper modeling with intelligent, data‐driven controllers, offering a high‐performance and energy‐efficient solution for real‐time seismic mitigation in tall telecommunication structures.

Arunvaratharaj, T.; Suresh kumar, P.

doi: 10.1002/tal.70105pmid: N/A

This study introduces a novel hybrid mechanism that integrates posttensioning tendons with advanced shear connectors to enhance the structural performance of composite fiber deck–concrete systems. The primary objective is to overcome challenges such as interface debonding, inefficient load transfer, and excessive deflection that often compromise the durability and efficiency of existing composite structures. To evaluate the proposed system, a series of experimental tests were conducted on scaled composite specimens incorporating the hybrid mechanism. Parameters such as load‐bearing capacity, midspan deflection, shear resistance, and energy absorption were systematically measured under both static and dynamic loading conditions. Finite element modeling and analytical simulations were also employed to validate and complement the experimental findings. The results demonstrated that the hybrid system achieved up to a 30% increase in load‐carrying capacity and a 20% reduction in deflection compared to traditional configurations. These findings confirm the effectiveness of the hybrid approach in enhancing structural stiffness, promoting uniform stress distribution, and improving the overall resilience and serviceability of fiber‐reinforced composite deck systems.

Verma, Himanshoo; Sonparote, Ranjan S.

doi: 10.1002/tal.70109pmid: N/A

This study employs computational fluid dynamics (CFD) to investigate the interference effects of side tall buildings (interfering building [IB]) on a tall rectangular building (primary building [PB]). Various configurations involving an IB and a PB are examined, with the IB being shifted in the x, y, and x‐y directions. Key aerodynamic parameters including force coefficients (CF), moment coefficients (CM), and mean pressure coefficients (CPMEAN) on the PB are analyzed to quantify the impact of IB locations. Findings reveal that shifting the IB by 0.2 L (L is the length of PB) in the x or y direction leads to significant increases in CF and CM. Critical IB locations are identified, emphasizing the importance of specific displacement scenarios on building faces. Additionally, CPMEAN analysis highlights the heightened sensitivity of certain faces to IB positioning. Notably, the study underscores the substantial increase in pressure on the back face of the PB in certain configurations, necessitating careful consideration during construction. Furthermore, asymmetry in wake regions is observed, particularly near the right side face (U), indicating the need for special attention to side faces in similar building arrangements. These findings offer valuable insights for optimizing tall building designs in urban environments.

doi: 10.1002/tal.2151pmid: N/A

No abstract is available for this article.

Zhang, Yantai; Gu, Yujie; Zhang, Jingpu; Zheng, Kaiqi; Wen, Jiayi; Leng, Yubing; Wei, Yang

doi: 10.1002/tal.70108pmid: N/A

This study advances the performance‐based plastic design (PBPD) method for the application of buckling‐restrained braces (BRB) in laminated bamboo frame (LBF) structures. A vulnerability analysis discusses the key parameters involved in the design method and their impact on the reinforcement effectiveness. Multistripe analysis was employed to generate vulnerability curves for both structures across various limit states, while Latin hypercube sampling (LHS) was utilized to sample modeling parameters. The addition of BRB supports markedly increases the lateral stiffness of LBF structures, thereby improving their seismic performance. The analysis reveals that the effectiveness of BRB diminishes from approximately 50% to around 20% as the ultimate drift ratio (θu) increases. In the PBPD method, the important design parameter—story shear ratio (p)—is also affected by θu. As θu rises, the p‐value that achieves maximum median intensity in the vulnerability function increases. Furthermore, the inclusion of BRB reduces the overall modeling uncertainty of the structure, indicating that modeling uncertainty significantly influences the vulnerability curves of LBF structures. Under the excitation of near‐field earthquakes, the annual collapse probability of the BRBLBF structure was found to comply with existing regulations and requirements.