Shear-lag effect and its effect on the design of high-rise buildings

For super high-rise buildings, the analysis and selection of suitable structural solutions are very important. The structure has not only to carry the gravity loads (self-weight, live load, etc.), but also to resist lateral loads (wind and earthquake loads). As the buildings become taller, the demand on different structural systems dramatically increases. The article considers the division of the structural systems of tall buildings into two main categories - interior structures for which the major part of the lateral load resisting system is located within the interior of the building, and exterior structures for which the major part of the lateral load resisting system is located at the building perimeter. The basic types of each of the main structural categories are described. In particular, the framed tube structures, which belong to the second main category of exterior structures, seem to be very efficient. That type of structure system allows tall buildings resist the lateral loads. However, those tube systems are affected by shear lag effect - a nonlinear distribution of stresses across the sides of the section, which is commonly found in box girders under lateral loads. Based on a numerical example, some general conclusions for the influence of the shear-lag effect on frequencies, periods, distribution and variation of the magnitude of the internal forces in the structure are presented.

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Parametric Analysis of the Shear Lag Effect in Tube Structural Systems of Tall Buildings

Applied Sciences ◽

10.3390/app11010278 ◽

2020 ◽

Vol 11 (1) ◽

pp. 278

Author(s):

Ivan Hafner ◽

Anđelko Vlašić ◽

Tomislav Kišiček ◽

Tvrtko Renić

Keyword(s):

Parametric Analysis ◽

Numerical Models ◽

Tall Buildings ◽

Structural Systems ◽

Structural Elements ◽

Structural System ◽

Shear Lag ◽

Shear Lag Effect ◽

Lag Effect ◽

Secondary Structural Elements

Horizontal loads such as earthquake and wind are considered dominant loads for the design of tall buildings. One of the most efficient structural systems in this regard is the tube structural system. Even though such systems have a high resistance when it comes to horizontal loads, the shear lag effect that is characterized by an incomplete and uneven activation of vertical elements may cause a series of problems such as the deformation of internal panels and secondary structural elements, which cumulatively grow with the height of the building. In this paper, the shear lag effect in a typical tube structure will be observed and analyzed on a series of different numerical models. A parametric analysis will be conducted with a great number of variations in the structural elements and building layout, for the purpose of giving recommendations for an optimal design of a tube structural system.

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Lateral Displacement and Shear Lag Effect of Combination of Diagrid-Frame

E3S Web of Conferences ◽

10.1051/e3sconf/20183401009 ◽

2018 ◽

Vol 34 ◽

pp. 01009 ◽

Cited By ~ 1

Author(s):

Roslida Abd. Samat ◽

Fong Teng Chua ◽

Nur Akmal Hayati Mohd Mustakim ◽

Sariffuddin Saad ◽

Suhaimi Abu Bakar

Keyword(s):

Lateral Displacement ◽

Tall Buildings ◽

Ground Level ◽

Lateral Load ◽

Tall Building ◽

Shear Lag ◽

Shear Lag Effect ◽

Lag Effect ◽

Level 1 ◽

Diagrid Structure

Diagrid system, which is the portmanteau of diagonal grid member, is an exterior lateral load resisting system for tall building that has gained a wide acceptance in the design of tall buildings. There is abundance of researches that studied the efficiency of diagrid systems, which are constructed from the ground level to the top of the buildings in resisting the lateral load. Nevertheless, no study had been performed on the effectiveness of the diagrid that is constructed above other tall building systems despite the existence of a few buildings in the world that employ such system. The objective of this research is to understand the behavior of the lateral displacement and shear lag effect due to wind load when the diagrid structure is constructed above a frame. Models of 60-story buildings with a footprint of 36m x 36m were analyzed by using Staad.Pro software. The level where the diagrid members started was altered. The lateral displacement was reduced to 60.6 percent and 41 percent of the lateral displacement of a building with full frame system when the combination of frame-diagrid that had the diagrid started at Level 1 and Level 45, respectively were employed. Furthermore, the shear lag ratio was reduced from 1.7 to 1.3 when the level where the diagrid started was increased from Level 1 to Level 45.

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Study of shear lag effect in a hybrid structural system for high-rise buildings

Technology Drivers: Engine for Growth ◽

10.1201/9780203713143-23 ◽

2018 ◽

pp. 153-158

Author(s):

Deep Modi ◽

Paresh V. Patel ◽

Digesh Joshi

Keyword(s):

Structural System ◽

Shear Lag ◽

Shear Lag Effect ◽

High Rise ◽

Lag Effect

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Analytical Study on Effect of Geometry of Tall Buildings on Diagrid Structural Systems Subjected to Lateral Loads

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.857.47 ◽

2016 ◽

Vol 857 ◽

pp. 47-52

Author(s):

Elsa Alexander Anjana ◽

R. Renjith ◽

Binu M. Issac

Keyword(s):

Response Spectrum ◽

Tall Buildings ◽

Structural Systems ◽

Lateral Loads ◽

Structural System ◽

Structural Efficiency ◽

High Rise ◽

Time Period ◽

Architectural Planning ◽

And Performance

Structural design of high rise buildings is governed by lateral loads due to wind or earthquake. As the height of building increases, the lateral load resisting system becomes more important than the structural system that resists the gravitational loads. Recently, diagrid structural system are widely used for tall buildings due to its structural efficiency and flexibility in architectural planning. Diagrid structural system is made around the perimeter of building in the form of a triangulated truss system by intersecting the diagonal and horizontal members. Diagonal members in diagrid structural systems can carry gravity loads as well as lateral loads. Lateral loads are resisted by axial action of the diagonals compared to bending of vertical columns in framed tube structure. The structural efficiency of diagrid system also helps in avoiding interior and corner columns, thereby allowing significant flexibility with the floor plan. In this paper, effect of lateral loads on steel diagrid buildings are studied. Square and rectangular buildings of same plan area with diagrid structural system is considered for the study. Diagrid modules extending upto 2,4,6,8 and 12 storeys are evaluated. Static analysis for the gravity loads, wind and earthquake and response spectrum analysis are carried out for these different combinations of plan shape and diagrid modules and performance of all these diagrid models i.e., storey displacement, storey drift and modal time period are evaluated and compared in this study.

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ANALYSIS OF MAXIMUM DEFORMATION OF HIGH RISE BUILDINGS WITH OUTRIGGER SYSTEM AGAINST WIND LOAD

Jurnal Infrastruktur ◽

10.35814/infrastruktur.v6i2.1736 ◽

2020 ◽

Vol 6 (2) ◽

pp. 141-149

Author(s):

Fadli Kurnia ◽

Resti Nur Arini ◽

Dwi Ariyani ◽

Soni

Keyword(s):

Tall Buildings ◽

Wind Load ◽

Wind Loads ◽

Structural Systems ◽

Maximum Deflection ◽

Lateral Loads ◽

Optimum Location ◽

Maximum Deformation ◽

High Rise ◽

Story Drift

Outrigger structural systems are quite effective using the lateral loads on tall buildings, one of the main benefits of utilization outrigger is that it can reduce deformation and the danger of inter-story drift caused by lateral loads acting on the building. In this case, wind loads will be viewed as a lateral load because the wind load acting on tall buildings can also cause deformation of the building. The implementation of the outrigger system is viewed from different positions to see the deformation that occurs and the placement of the maximum location. The results of the analysis of wind loads reviewed on these buildings have proven that the use of outriggers in buildings can reduce displacement by 19.58%, and inter-storey drifts by 13.24%, which is applied in a position of ½ of the building height. The optimum location of the outrigger installation can also be determined by calculating the analysis of the maximum deflection that occurs on the 40th floor.

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