Due to the sensitivity of concrete frames to the lateral displacement especially in the case of tall buildings, it is useful to improve the behavior to resistance the lateral displacement through bracing. Bracing can be used in cases of rehabilitatio
n and increasing the efficiency of existing concrete buildings. Varied shapes of bracing for concrete frames in order to achieve opening for windows and doors in the wall of frames. The research aims to give an idea for designer on the effect of the shape of bracing on the cross section forces generated in the elements of R/C tall buildings frame elements.
The Study was conducted on R/C frame which consist from five spans, and fifteen storeys. It has compared different shapes of metal bracing, which are X, V, K and O. Calculation were based on Program CSI-SAP 2000.
Conducted compared for the storylateral displacement of concrete frame in relation with the bracing shape. It shows that the bracing have large effect to reduce the storey lateral displacement, in the case of the bracing with X and V shape decreased the value of displacement in the last story in ratio 52.38%, in the case of bracing with K and O shape decreased in ratio 23.07%.
Conducted detailed comparison for the value of cross section i.e. Moments, shear and axial forces in beams and columns of first and second floor frame in relationship of bracing shape. It concludes thatX and V bracing have large effect on the concrete tall buildings frame, as well as in the cases of improving the efficiency of existing R/C frame buildings.
Most existing structures are not designed with cod
requirements to meet seismic risk, Therefor methods for
strengthening and stiffening existing buildings are important .
This study is comparing between strengthening by adding shear
wall or by ad
ding steel bracing.X -V
The study shows the importance of using steel bracing system
that is excellent approach for strengthening and stiffening
existing buildings with small increase in mass ,the study also
approved that the constant value of R(response factor)(as
mentioned in the Syrian code and UBC97) is not completely
correct.
Frame structures contribute to resist the seismic loads. On the other hand, many techniques were used to improve the resistance against lateral loads where steel shear walls are considered to be one of these ways.
This research aims to study the eff
ect of strengthening of the
reinforced concrete frames inserting perforated steel plate shear walls embedded within the frame. This study applied numerical analysis using Finite Element Method (FEM) using nonlinear pushover analysis based on geometrically and Materially Non-Linear Analysis (GMNLA) was performed. To study the behavior of the steel plate that seal the hall span of the reinforced concrete frame against lateral loads. Moreover, perforated steel plate was studied taking under consideration the effect of the number and the area of the perforations and strengthening of the perforations circumference on the resistance was observed.
This study conclude that using a perforated steel plate shear wall with reinforced- concrete frames and strengthening of the perforations circumference can enhance the resistance significantly beside that it decrease the frame deflection.
This study aims to investigate the capacity of numerical
models to reproduce the monotonic behavior of reinforced concrete
framed structures.
This research investigates the behavior of RC frames
strengthened using steel jacket technique and the impact of using
this technique on the frame specifications was examined in terms of
rigidity, ductility and resistance.
