Chapter 1: Design of Roof and Truss (B+G+4 Apartment) PDF

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PROJECT BY ABDIRASHID MOHAMED DAHIR EMAIL:[email protected] Chapter 1: Design of Roof and Truss (B+G+4 Apartment) Writer’s Note: This is a project by Abdirashid Mohamed Dahir who holds BSc in Civil Engineering from Debre Berhan University, Ethiopia. All reference materials can be found at the end ...

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PROJECT BY ABDIRASHID MOHAMED DAHIR EMAIL:[email protected]

Chapter 1: Design of Roof and Truss (B+G+4 Apartment) Writer’s Note: This is a project by Abdirashid Mohamed Dahir who holds BSc in Civil Engineering from Debre Berhan University, Ethiopia. All reference materials can be found at the end of the lecture tailored for civil engineering students. Kindly, don’t hesitate to drop your comments to the email: [email protected] 1. Wind Analysis 1.1 Introduction We consider in our structural project, the design of G+4 apartment building with a basement storey, and located in Debre Berhan City, North Shewa, in the Amhara regional State of Ethiopia. Wind forces are variable loads which act directly on the internal and external surface of structures. The intensity of wind load on a structure is related to the square of the wind velocity and the dimensions of the members that are resisting the wind (frontal area). Wind velocity is dependent on geographical location, the height of the structure, the topography of the area and the roughness of the surrounding terrain. Wind is a moving air which in turn possesses energy and this kinetic energy should be resisted by using appropriate deign for different kinds of structural elements like roofs , and walls .The action of wind can be a type of suction or pressure to our structures both externally or internally .However these effects are more magnified for structure with more openings and large surface areas .And we focus on sensitive part of the building that is roofs (both hipped and flat roofs) for analysis and design of its parts. 1.1.1 Method of Analysis Response of structure to variable action of wind could either be background component that involves static deflection or resonant component which is relatively small and involving dynamic vibration. The latter is widely considered for tall and

PROJECT BY ABDIRASHID MOHAMED DAHIR EMAIL:[email protected]

flexible structures. Here, our analysis is based on Background resonant or Quasistatic gust load. 1.1.2 Why static? It is critical for engineers to investigate dynamic coefficient for gust wind response as stipulated EBCS-1, 1995 section 3.9.3; a building which satisfies the criterion: (For cd...