دانلود رایگان مقاله انگلیسی روش طراحی مستقیم و نمودار طراحی برای ستون های بتن مسلح و دیوارهای برشی - الزویر 2018

ABSTRACT

Design of reinforced concrete columns and shear walls is an iterative process. The capacity of an assumed section is checked using interaction diagrams and the procedure continues until a satisfactory section is found. This study introduces a “Direct Design” method and “Design Diagrams”. The direct design method is an analytical approach by which the required area of reinforcement for short reinforced concrete columns or shear walls is determined directly without using an interaction diagram. This method provides a fitted solution for a reinforced concrete section; the capacity of the section is equal to the demand from the applied loads and moments. For each column or shear wall, many fitted sections with different sizes and bar arrangements could be employed. A design diagram shows all possible fitted sections for a particular column or shear wall. This study provides an algorithm for making design diagrams.

CONCLUSION

Direct design method is an analytical method by which the required area of reinforcement for short reinforced concrete columns or shear walls is directly calculated without using interaction diagrams. Some other advantages of this method are:

 It could be used for any column or shear wall section with any arbitrary bar arrangement.

 It directly provides a fitted section without going through a trial-and-error procedure.

 It is not limited to any particular stress-strain diagram for concrete and reinforcement.

 The numerical solution of this method is very efficient, accurate, and fast in computer calculations.

Efficiency of direct design method provides a practical way for making design diagrams. The advantages of design diagram are:

 Shows all possible fitted column or shear wall cross sections in one diagram.

 Eliminates trial-and-error procedure from column design procedure.

 Shows the acceptable limitation for section dimension and bar arrangement.

 ACI and most of the other concrete codes, consider slenderness effect by magnifying the applied moments. Moment magnification is highly dependent on loads, column boundary conditions and many other factors. Considering all these additional factors in the presented method would produce more complexity and will be incorporated in a future study.

 In order to apply the direct design method to slender columns, the applied moments on the columns should be first magnified according to ACI 318.