The Structural Design of Tall and Special Buildings

Liu, Zhenzhen; Ma, Xiaoxia; Li, Na; Chen, Juan; Lu, Yiyan

doi: 10.1002/tal.2155pmid: N/A

Fiber‐reinforced concrete‐filled steel tube (CFST) adopts the microskeleton and bridging effect of fibers, thereby optimizing the confinement effect between the steel tube and concrete core while reducing the concrete core friability. This structure offers a viable solution for solving the interface disengagement and insufficient ductility problems of conventional CFSTs. For further theoretical research and engineering application, the mechanical properties of fiber‐reinforced CFSTs under different loading conditions are reviewed. The research results are summarized, and future research scopes are suggested. The literature review shows that adding fibers improves the ductility of CFSTs significantly but the bearing capacity only slightly. The bond strength between steel tube and concrete core is enhanced by fibers, and the degradation in the bond strength is simultaneously delayed. However, in existing research, the mechanical properties and design method are still inadequate. More experimental works, further theoretical analyses, and numerical simulation should be undertaken to establish the quantitative relations between the generalized fiber parameters and structural performance of CFSTs. Future research should propose a unified design theory of fiber‐reinforced CFST structures based on service performance requirements.

Chen, Junling; Lin, Wenmin; Li, Jinwei

doi: 10.1002/tal.2156pmid: N/A

More and more prefabricated steel–concrete hybrid wind turbine towers have been built because of their better lateral stiffness than those of the full steel towers, in which epoxy resin joints are commonly adopted at the horizontal joint between two ring units for improving the erection speed. In fact, epoxy resin joints are designed in the same way as dry joints due to the very thin thickness of epoxy resin layer, in which epoxy resin only acts as a leveling blanket and sealer for jointing and compensates for the unevenness of the contact surface between two ring units. The current design method for the resistance to torsional moment at the horizontal joint is not reasonable because of the unreasonable assumption of Saint‐Venant's torsional theory. The integral expressions of the ultimate torsional moment at the horizontal joint with and without shear force are derived, respectively. The solution of the integral expressions for the ultimate torsional moment is realized by Python programming. The refined finite element analyses of two cases are compared with the existing small‐scale tests with segmental aluminum tubes, which verifies the calculation accuracy of the proposed integral method. In the modified integral model of the ultimate torsional moment, a correction term of the resistance to torsional moment and a more suitable distribution of shear stress under the action of horizontal shear force are proposed to obtain a more accurate ultimate torsional moment. Finally, 36 sets of cases with typical dimensions and axial forces in practical engineering are analyzed by the proposed integral model in the absence of horizontal shear force. One six‐parameter model for calculating the ultimate torsional moment is fitted by the least square method. A discount factor is proposed to consider the influence of the horizontal shear force on the ultimate torsional moment.

Lima, Douglas Mateus; Medeiros, Iálysson da Silva; Santos, Romário Barros; Medeiros Alas, Luis Ernesto; López‐Yánez, Pablo Aníbal

doi: 10.1002/tal.2158pmid: N/A

Aiming to achieve efficient structural performance, this article presents a methodology for the design of the shell structure and dimensioning of the connections of an S355J2 tubular steel tower with a height of 80 m, compatible with a SWT‐2.3‐93 wind turbine. The tower is made up of three segments, interconnected by flanged connections made of high‐strength steel. The analysis considers various load cases, taking into account stress and resistance in different directions, as well as designing connections using Petersen's theory, according to maximum strength and fatigue criteria. The results indicate that the circumferential stresses are nearly negligible compared with the resistant stresses, while the shear stress is significantly higher at the base due to the torsional moment. Meridional stress determines the stability of the structure, requiring consideration of internal pressure for safety. Maximum stress values range from 135.00 to 168.47 MPa, depending on the location along the tower height. Flanged connections meet the strength and fatigue criteria, with the first flange enduring 63.0% of the fatigue effect and the second, 39.7%. Therefore, the results provide reliable information and methodologies for tower design, contributing to the practical and efficient development of these structures.

Tian, Jianbo; Liu, Gaoju; Li, Bolin; Xia, Yuanyuan; Zhou, Wenjing; Liang, Gang

doi: 10.1002/tal.2154pmid: N/A

To better meet the evolving requirements of industrialized building system, this paper introduces a novel approach by proposing the utilization of a plate‐reinforced composite (PRC) coupling beam, which incorporates a steel bar truss deck as a substitute for the conventional reinforced concrete (RC) slab. In order to study the effect of different types of RC slabs on the performance of PRC coupling beams, the low‐cyclic reversed loading test was carried out on three PRC coupling beams. The differences of failure modes, load bearing capacity, stiffness degradation, and energy dissipation capacity of each coupling beam are analyzed. The finite element software ABAQUS is used to analyze the stress distribution in the concrete, steel plate, and reinforcement skeleton of the novel coupling beam. The results show that the incorporation of a steel bar truss deck in PRC coupling beams with a small span‐to‐depth ratio can effectively enhance their shear bearing capacity and energy dissipation capacity. The inclusion of a slab significantly enhances the load‐bearing capacity of the coupling beam, while the utilization of a steel bar truss deck in PRC coupling beams greatly improves their overall bearing capacity. The PRC coupling beams featuring a steel bar truss deck exhibit superior load capacity compared to those with conventional RC slabs. The cumulative energy dissipation at the damage point in PRC beams with a steel bar truss deck is 1.39 times greater than that of the coupling beam without slabs and 1.18 times higher than that of the coupling beam with traditional RC slabs.

Xue, Bin; Lu, Wensheng; Yang, Yongqiang; Ren, Xiangxiang

doi: 10.1002/tal.2159pmid: N/A

Under earthquake excitations, the lead core inside the lead‐rubber bearing (LRB) generates heat, causing the mechanical degradation of LRBs. However, the heating effect is not commonly considered in the seismic analysis and design of base‐isolated structures with LRBs, which may underestimate the seismic response of structures, especially under ground motions with certain specific characteristics. This paper aims to reveal the influence of ground motion characteristics on the heating effect and provide useful references for the seismic analysis and design. In this study, the validated LRB model considering heating effect was employed in a base‐isolated building calibrated by testing data. Ground motion characteristics including amplitude, duration, and frequency content were separated by spectrally equivalent and different records. The results indicate that the rate and peak of the lead core temperature rise are strongly correlated to ground motion characteristics. Seismic responses ignoring the heating effect are underestimated, and this underestimate varies as the amplitude, duration, and frequency content change and reaches up to 60% in the studied case. Note that seismic responses of the isolation system are more affected by heating effects than the superstructure, and the duration shows a more significant influence on the stiffness degradation of LRBs than the frequency content. It is strongly recommended that the required duration of ground motions should be raised and the low stories of the superstructure should be reinforced for isolated structures with LRBs. The significant duration indicator DS5–95 is more reasonable than DS5–75 in the analysis of the heating effect.

doi: 10.1002/tal.2032pmid: N/A

No abstract is available for this article.

ZhongJun, Yu; Jianfeng, Wang; Zhibing, Zou

doi: 10.1002/tal.2152pmid: N/A

For super high‐rise buildings with a height of more than 400 m, differential settlement control of foundation is a crucial aspect in structural design. In previous engineering cases, except that the foundation or piles can be directly supported on bedrock, basement wing walls were commonly used to coordinate the differential settlement of foundation between the perimeter columns and the core. However, wing walls could also have negative effects on the basement usage. This article studied and compared the effects of arranging basement wing walls and adjusting pile length on differential settlement of the foundation. The scheme of adjusting pile length considering the interaction between piles, foundation, and superstructure was proposed to control differential settlement of the foundation, and the effectiveness of canceling basement wing walls was verified. Subsequently, a calculation program was developed to automatically optimize pile lengths by region. Finally, the above achievements were applied to the project of China International Silk Road Center Building with a building height of 498 m, making it the tallest building in China located on nonrock stratum and without basement wing walls.