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Wind Load Analysis of Buildings
Published in Bungale S. Taranath, Tall Building Design, 2016
Topographic factor (Kzt) is used to include the wind speed-up effect in the calculations of the design wind loads. Wind speed-up effects at isolated hills, ridges, and escarpments with abrupt changes in topography. Escarpment is defined as cliff or steep slope generally separating two levels or gently sloping areas. Topographic effects are considered if all of the following ASCE 7-10 conditions listed in the ASCE Section 26.8.1 are met. It is not the intent of ASCE Section 26.8 to address the general case of wind flow over hilly or complex terrain for which engineering judgment, expert advice or the wind tunnel procedure may be required. The hill, ridge, or escarpment is isolated and unobstructed upwind by other similar topographic features of comparable height for 100 times the height of the topographic feature (100H) or 2 mi, whichever is less. This distance shall be measured horizontally from the point at which the height H of the hill, ridge, or escarpment is determined.The hill, ridge, or escarpment protrudes above the height of upwind terrain features within a 2-mile radius in any quadrant by a factor of two or more.The structure is located as shown in ASCE Figure 26.8-1 in the upper one-half of a hill or ridge or near the crest of an escarpment.
Review of ASCE 7-16
Published in Syed Mehdi Ashraf, Structural Building Design: Wind and Flood Loads, 2018
Topographic Factor (Kzt) is used to include the wind speed-up effect in the calculations of the design wind loads. Wind speed-up effects occur at isolated hills, ridges and escarpments with abrupt changes in topography. Escarpment is defined as cliff or steep slope generally separating two levels or gently sloping areas. Topographic effects are considered if all the following ASCE 7-16 conditions, listed in ASCE Section 26.8.1, are met. It is not the intent of ASCE Section 26.8 to address the general case of wind flow over hilly or complex terrain for which engineering judgment, expert advice or the Wind Tunnel Procedure may be required.
Wind Load Analysis of Buildings
Published in Syed Mehdi Ashraf, Practical Design of Reinforced Concrete Buildings, 2017
The topographic factor (Kzt) is used to include the wind speed-up effect in the calculations of the design wind loads. Wind speed-up effects at isolated hills, ridges, and escarpments with abrupt changes in topography. Escarpment is defined as cliff or steep slope generally separating two levels or gently sloping areas. Topographic effects are considered if all of the following ASCE 7-10 conditions listed in the ASCE section 26.8.1 are met. It is not the intent of ASCE section 26.8 to address the general case of wind flow over hilly or complex terrain for which engineering judgment, expert advice, or a wind tunnel procedure may be required.The hill, ridge, or escarpment is isolated and unobstructed upwind by other similar topographic features of comparable height for 100 times the height of the topographic feature (100 H) or 2 miles, whichever is less. This distance shall be measured horizontally from the point at which the height H of the hill, ridge, or escarpment is determined.The hill, ridge, or escarpment protrudes above the height of upwind terrain features within a 2-mile radius in any quadrant by a factor of two or more.The structure is located as shown in ASCE figure 26.8-1 in the upper one-half of a hill, ridge, or near the crest of an escarpment.Factors K1, K2, and K3 are calculated from figure 26.8-1, and the topographic factor Kzt is calculated using the following equation. If the site conditions do not meet all of the above conditions, then Kzt is 1.0: Kzt=1+K1K2K32
Contamination of Arable Soil with Toxic Trace Elements (Tes) around Mine Sites and the Assessment of Associated Human Health Risks
Published in Soil and Sediment Contamination: An International Journal, 2023
Gregory Udie Sikakwe, Godswill Abam Eyong, Benneth Uduak Ilaomo
The study area is within Enyigba, Ameri, and Ameka Pb-Zn ore mine sites in Abakaliki district, Ebonyi state, Nigeria. It is situated between latitudes 6° 9’ to 6° 24ʹN and longitude 8° 5’ to 8° 10ʹE (Figure 1) at a distance of about 14 km southeast of Abakaliki urban. The localities are characterized by shale outcrops, which host Pb-Zn mineral deposits. There are ridges and flat lands underlain by shale of the Asu River Group. These ridges and flat lands host the lead-zinc veins and form watersheds that are sources of springs and streams in the area. Streams generally flow along narrow valleys beneath the escarpment. Some of the saline springs are along stream valleys and are flooded during the rainy season. Stream channels have tributaries that develop into rectangular, closely spaced drainage patterns, because the soils and bedrocks have poor resistance to erosion. Clay enhances runoff that makes the area dominated by sheet erosion. There is a loss of precipitation because of high direct runoff, surface retention and overland flow. There is waterlogging of weathered clay and shale soil that occurs in pockets within the valleys and flood plains.