scholarly journals Structural Improvements for Tall Buildings under Wind Loads: Comparative Study

2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Nicola Longarini ◽  
Luigi Cabras ◽  
Marco Zucca ◽  
Suvash Chapain ◽  
Aly Mousaad Aly
Keyword(s):  
Comparative Study ◽  
Tall Buildings ◽  
Force Balance ◽  
Wind Loads ◽  
Wind Tunnel Testing ◽  
Optimal Balance ◽  
Mass Damper ◽  
Wind Actions ◽  
Design Loads ◽  
Italian Design

The behavior of a very slender building is investigated under wind loads, to satisfy both strength and serviceability (comfort) design criteria. To evaluate the wind effects, wind tunnel testing and structural analysis were conducted, by two different procedures: (i) Pressure Integration Method (PIM), with finite element modeling, and (ii) High Frequency Force Balance (HFFB) technique. The results from both approaches are compared with those obtained from Eurocode 1 and the Italian design codes, emphasizing the need to further deepen the understanding of problems related to wind actions on such type of structure with high geometrical slenderness. In order to reduce wind induced effects, structural and damping solutions are proposed and discussed in a comparative study. These solutions include (1) height reduction, (2) steel belts, (3) tuned mass damper, (4) viscous dampers, and (5) orientation change. Each solution is studied in detail, along with its advantages and limitations, and the reductions in the design loads and structural displacements and acceleration are quantified. The study shows the potential of damping enhancement in the building to mitigate vibrations and reduce design loads and hence provide an optimal balance among resilience, serviceability, and sustainability requirements.

A New Generation of Tools for the Design of Tall Buildings Subjected to Wind Loads

2008 ◽  
Author(s):  
Emil Simiu ◽  
Rene D. Gabbai
Keyword(s):  
Structural Engineering ◽  
Tall Buildings ◽  
Building Envelope ◽  
Force Balance ◽  
Wind Loads ◽  
Individual Member ◽  
Engineering Practice ◽  
Wind Effects ◽  
Uncertainty Estimates ◽  
Internal Forces

Current approaches to the estimation of wind-induced wind effects on tall buildings are based largely on 1970s and 1980s technology, and were shown to result in some cases in errors of up to 40%. Improvements are needed in: (i) the description of direction-dependent aerodynamics; (ii) the description of the direction-dependent extreme wind climate; (iii) the estimation of inertial wind effects induced by fluctuating aerodynamic forces acting on the entire building envelope; (iv) the estimation of uncertainties inherent in the wind effects; and (v) the use of applied wind forces, calculated inertial forces, and uncertainty estimates, to obtain via influence coefficients accurate and risk-consistent estimates of wind-induced internal forces or demand-to-capacity ratios for any individual structural member. Methods used in current wind engineering practice are especially deficient when the distribution of the wind loads over the building surface and their effects at levels other than the building base are not known, as is the case when measurements are obtained by the High-Frequency Force Balance method, particularly in the presence of aerodynamic interference effects due to neighboring buildings. The paper describes a procedure that makes it possible to estimate wind-induced internal forces and demand-to-capacity ratios in any individual member by: developing aerodynamic and wind climatological data sets, as well as aerodynamic/climatological directional interaction models; significantly improving the quality of the design via rigorous structural engineering methods made possible by modern computational resources; and properly accounting for knowledge uncertainties. The paper covers estimates of wind effects required for allowable stress design, wherein knowledge uncertainties pertaining to the parameters that determine the wind loading are not considered, as well as estimates required for strength design, in which these uncertainties need to be accounted for explicitly.

Optimizing Skyscrapers' Spatial Integrated DSF-MTMD System Under Wind Loads

2019 ◽  
Author(s):  
Oren Lavan ◽  
Liran Anaby
Keyword(s):  
Structural Engineering ◽  
Tall Buildings ◽  
Point Of View ◽  
Wind Loads ◽  
Optimization Approach ◽  
Wind Effects ◽  
Mass Damper ◽  
Double Skin ◽  
The Cost ◽  
Formal Optimization

<p>From a structural engineering point of view, wind effects pose one of the major challenges to tall buildings. From a performance/architectural point of view, climatologic aspects pose a major challenge. Remedies for each challenge separately have been proposed. One of the remedies for wind effects is the Tunes-Mass-Damper (TMD) or multiple TMD's. To mitigate climatological issues, the Double-Skin-Façade (DSF) has been developed. Recently it has been suggested to take advantage of the space between the two skins of the DSF system to allocate TMD's.</p><p>In this work, another step is taken towards a single remedy for both challenges. A modified version of the TMD-DSF system proposed by Moon (2016) is presented. That is, parts of the mass of the DSF envelope itself are used as part of a multiple TMD (MTMD) system. This is obtained by connecting these parts to the building using springs and dampers while allowing the DSF to move parallel to the floor edges. Furthermore, the DSF-MTMD system is optimized using a formal optimization approach. The optimization indicates which parts of the envelope should be connected to the building rigidly and which should be used as TMD's. Furthermore, the properties of the springs and the dampers are determined by minimizing the cost associated with transforming the DSF system to a DSF-MTMD system and limiting wind responses to desired values.</p>

Dynamic Wind Load Combination for a Tall Building Based on Copula Functions

2017 ◽  
Vol 17 (08) ◽  
pp. 1750092 ◽  
Author(s):  
M. F. Huang ◽  
Zhibin Tu ◽  
Qiang Li ◽  
Wenjuan Lou ◽  
Q. S. Li
Keyword(s):  
Wind Tunnel Test ◽  
Time History ◽  
Tall Buildings ◽  
Wind Load ◽  
Probabilistic Methods ◽  
Force Balance ◽  
Wind Loads ◽  
Exceedance Probability ◽  
Copula Functions ◽  
Combination Rules

Dynamic wind loads on tall buildings can be decomposed into three components, i.e. two translational components and one torsional component. When one component reaches its maximum, the other two components have low probability to take their maximum values. It is common to use combination coefficients for estimating the mean extremes of linearly combined wind loads. The traditional design practice for determining wind load combinations relies partly on some approximate combination rules and lacks a systematic and reliable method. Based on the high frequency force balance (HFFB) testing results, wind loads can be acquired in terms of time history data, which provides necessary information for the more rigorous determination of combination coefficients by probabilistic methods. In this paper, a 3D copula-based approach is proposed for determining the combination coefficients for three stochastic wind loads associated with a specific exceedance probability and a set of 3D realizable equivalent static wind loads (ESWLs) on tall buildings. Using the measured base moment and torque data by the HFFB wind tunnel test, a case study is presented to illustrate the effectiveness of the proposed framework to determine the dynamic wind load combinations and associated 3D realizable ESWLs on a full-scale 60-story building.

EFFECT OF HEIGHT AND ORIENTATION OF INTERFERING BUILDINGS ON WIND LOADS ON TALL BUILDINGS

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Bharat Chauhan ◽  
Ashok Ahuja
Keyword(s):  
Wind Tunnel ◽  
Research Work ◽  
Tall Buildings ◽  
Relative Orientation ◽  
Force Balance ◽  
Wind Loads ◽  
Wind Tunnel Experiments ◽  
Cross Sectional ◽  
Sectional Shape ◽  
Component Force

The research work presented in this paper investigates the effect of interference on wind loads on a tall building (instrumented building) having rectangular cross-sectional shape due to the presence of two interfering buildings close to the instrumented building. The effect of interference on the instrumented building is studied with the variation of height and relative orientation of the interfering buildings with respect to the instrumented building. Wind tunnel experiments are undertaken using five component force balance load cell and the results are reported in the form of X-Y plots. The effect of interference in both shielding as well as enhancing the wind load on the instrumented building, is seen to increase with the increase in the height of the interfering building. Negative drag force is also observed in few cases where shielded part of the instrumented building is large. Value of torsion on the instrumented building is observed to be as high as ten times of that in the isolated case.

Wind loads on roof-mounted isolated solar panels of tall buildings through wind tunnel testing

Solar Energy ◽  
2022 ◽  
Vol 231 ◽  
pp. 607-622
Author(s):  
S.F. Dai ◽  
H.J. Liu ◽  
J.H. Yang ◽  
H.Y. Peng
Keyword(s):  
Wind Tunnel ◽  
Tall Buildings ◽  
Wind Loads ◽  
Wind Tunnel Testing ◽  
Solar Panels ◽  
Tunnel Testing

Design recommendations for wind loading on buildings of intermediate height

1989 ◽  
Vol 16 (6) ◽  
pp. 910-916 ◽  
Author(s):  
T. Stathopoulos ◽  
M. Dumitrescu-Brulotte
Keyword(s):  
Tall Buildings ◽  
Building Code ◽  
Wind Loads ◽  
Wind Loading ◽  
Code Design ◽  
Building Models ◽  
Concordia University ◽  
Open Country ◽  
Design Loads ◽  
Wind Pressures

The National Building Code of Canada (NBCC) specifies wind loads for the design of tall (height, H > width, W) and low (H < 10 m, or H < W and H < 20 m) buildings. Since there are no specifications for the design of buildings of intermediate height, the present project has been undertaken to help define wind loads appropriate for the design of such buildings. The experimental study was carried out at the boundary layer wind tunnel of the Centre for Building Studies at Concordia University. The methodology used for this project consisted of testing five square building models (12, 25, 55, 100, and 145 m high) under conditions simulating strong turbulent wind blowing over an open country terrain exposure. Both the lowest and the tallest buildings were tested for validation purposes. Statistics of wind induced pressures were measured at several points and areas on the walls and the roof of all buildings for both normal and oblique wind directions. Experimental data show good agreement with previous studies of buildings of similar height tested under different environmental and proximity conditions. Results for the intermediate height buildings are presented in the paper. Wind pressures are compared with the NBCC specifications for low and tall buildings. Key words: building, code, design, loads, pressure, roof, wall, wind.

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