Wind Load Statistics for Probability-Based Structural Design

Abstract

ASCE Standard 7, ''Minimum Design Loads for Buildings and Other Structures,'' has contained provisions for load combinations and load factors suitable for load and resistance factor design since its 1982 edition. Research in wind engineering in the intervening years has raised questions regarding the wind load factor 1.3 and load combinations in which the wind load appears in ASCE 7-95. This paper presents revised statistical models of wind load parameters based on more recent research and a Delphi, and reassesses the wind load combinations in ASCE Standard 7 probabilistically. The current approach to specifying wind loads in ASCE 7 does not lead to uniform reliability in inland and hurricane-prone regions of the country. It is recommended that the factor accounting for wind directionality effects should be separated from the load factor and presented in a separate table in the wind load section, that the wind load factor should be increased from 1.3 to approximately 1.5 or 1.6 to achieve reliability consistent with designs governed by gravity load combinations, and that the exposure classification procedure in ASCE Standard 7 should be revised to reduce the current high error rate in assigning exposures.

Probability‐based Design of Spun Concrete Beam‐columns

“…It is caused by the crowded rooms during special events and by mobile equipment during processes in civil and engineering buildings respectively. The probability distribution of resistance, R , and permanent action effect, G E , of reinforced concrete members is close to normal distribution (Ramsay et al 1979;Вадлуга 1979;Ellingwood 1981;ISO 2394ISO 1988EN 1990EN 2002EN 1992EN -1 2004JCSS 2000). According to these international standards, Gaussian or lognormal distributions may be assumed for sustained actions and Weibull, gamma or exponential distributions may be used for extraordinary actions representing non-stationary processes.…”

“…The mean and coefficient of variation as well as variance in this process may be defined as Rosowsky and Ellingwood (1992). Gumbel cumulative distribution is quite appropriate for the annual extreme snow and wind loads (Ellingwood 1981;JCSS 2000;Vrouwenvelder 2002). The mean values, coefficients of variation and variances in these load effects may be expressed as…”

Damage Analysis and Evaluation of Light Steel Structures Exposed to Wind Hazards

“…Garcia [71] established a probabilistic analysis framework for the vulnerability of typical light steel structures in the United States. Ellingwood [72][73][74][75] proposed a series of fragility analysis methodologies for assessing the response of light-frame wood construction exposed to stipulated extreme windstorms and earthquakes. Henderson and Ginger [76,77] proposed a series of vulnerability model for Australian high-set house or metal-clad industrial buildings to extreme wind loading for cyclonic regions.…”

Necesidad de revisión de cargas y factores parciales de la NSR-10 para el diseño de estructuras sometidas a acciones de viento

“…Se actualizó la metodología de análisis de cargas de viento acorde a estos mapas. Nótese que a diferencia de los realizado en Colombia, el cambio del γ W en el ASCE fue el resultado de un proceso de análisis que inició en 1999 [15] y concluyó en el año 2010 [16], y en la cual fue necesario obtener nuevas velocidades de diseño y desarrollar una nueva metodología de análisis.…”