Application of Genetic Programming for Determination of Wind Loads on Tall Buildings

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

Volume 3: Design; Tribology; Education ◽

10.1115/esda2008-59059 ◽

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.

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Parametric Analysis of Rotational Effects in Seismic Design of Tall Structures

Applied Sciences ◽

10.3390/app11020597 ◽

2021 ◽

Vol 11 (2) ◽

pp. 597

Author(s):

Milan Sokol ◽

Rudolf Ároch ◽

Katarína Lamperová ◽

Martin Marton ◽

Justo García-Sanz-Calcedo

Keyword(s):

Seismic Design ◽

Parametric Study ◽

Tall Buildings ◽

Soil Parameters ◽

Eurocode 8 ◽

Tall Structures ◽

Rotational Components ◽

Different Types ◽

Depth Study

This paper uses a parametric study to evaluate the significance of the rotational components of Earth’s motion in a seismic design. The parametric study is based on the procedures included in Eurocode 8, Part 6. Although the answer to the question of when the effects of rotational components are important is quite a complex one and requires a more in-depth study, our aim was to try to assess this question in a relatively quick manner and with acceptable accuracy. The first part of the paper is devoted to derivation of a simple formula that can be used for expressing the importance of rotational components in comparison with the classic seismic design without their usage. The quasi-static analysis, assuming inertial forces, is used. A crucial role plays the shape of the fundamental mode of the vibration. Due to simplicity reasons, well-known expression for estimation of the first eigenmode as an exponential function with different power coefficients that vary for different types of buildings is used. The possibility of changing the soil parameters is subsequently included into the formula for estimation of the fundamental frequency of tall buildings. In the next part, the overall seismic analyses of complex FEM models of 3D buildings and chimneys are performed. The results from those analyses are then compared with those from simplified calculations. The importance of the soil characteristics for determination of whether it is necessary to take into account the rotational effects is further discussed.

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

IABSE Congress, New York, New York 2019: The Evolving Metropolis ◽

10.2749/newyork.2019.1191 ◽

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>

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Determination of optimal frequency of tuned mass damper for super tall buildings subjected to service level earthquakes

IABSE Congress, Stockholm 2016: Challenges in Design and Construction of an Innovative and Sustainable Built Environment ◽

10.2749/stockholm.2016.0978 ◽

2016 ◽

Author(s):

Lei Zhang ◽

Xinzheng Lu ◽

Qing Jiang ◽

Lieping Ye

Keyword(s):

Tall Buildings ◽

Service Level ◽

Tuned Mass Damper ◽

Optimal Frequency ◽

Mass Damper

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Refined Mathematical Models for Across-Wind Loads of Rectangular Tall Buildings with Aerodynamic Modifications

International Journal of Structural Stability and Dynamics ◽

10.1142/s0219455421501315 ◽

2021 ◽

pp. 2150131

Author(s):

Yi Li ◽

Chao Li ◽

Qiu-Sheng Li ◽

Yong-Gui Li ◽

Fu-Bin Chen

Keyword(s):

Wind Tunnel ◽

Correlation Coefficients ◽

Tall Buildings ◽

Tall Building ◽

Experimental Results ◽

Dynamic Loads ◽

Wind Loads ◽

Empirical Formulas ◽

Benchmark Model ◽

Power Spectral

This paper aims to systematically study the across-wind loads of rectangular-shaped tall buildings with aerodynamic modifications and propose refined mathematic models accordingly. This study takes the CAARC (Commonwealth Advisory Aeronautical Research Council) standard tall building as a benchmark model and conducts a series of pressure measurements on the benchmark model and four CAARC models with different round corner rates (5%, 10%, 15% and 20%) in a boundary layer wind tunnel to investigate the across-wind dynamic loads of the typical tall building with different corner modifications. Based on the experimental results of the five models, base moment coefficients, power spectral densities and vertical correlation coefficients of the across-wind loads are compared and discussed. The analyzed results shown that the across-wind aerodynamic performance of the tall buildings can be effectively improved as the rounded corner rate increases. Taking the corner round rate and terrain category as two basic variables, empirical formulas for estimating the across-wind dynamic loads of CAARC standard tall buildings with various rounded corners are proposed on the basis of the wind tunnel testing results. The accuracy and applicability of the proposed formulas are verified by comparisons between the empirical formulas and the experimental results.

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