Comparison of Shear Wall Deformations and Forces Using Two Approaches

Comparison of Shear Wall Deformations and Forces Using Two Approaches 34 G. Gus Aswad, P.E. Bridge Engineer MK-Centennial Engineering Deerfield Beach, Florida Basel Djazmati Assistant Engineer Duke Engineering & Services Naperville, Illinoi s Alex Aswad, Ph.D., P.E. Professor of Engineering Civ il Engineering Program Penn State University at Harrisburg Middletown, Pennsylvania Shear walls have been used successfully in low and mid-rise precast concrete buildings for more than 35 years to provide the lateral resistance against wind and seismic forces . This study compa res the lateral deformations and section forces of cantilevered shear walls in four building layouts by two different procedures. Walls that are 7 to 30 ft (2. 13 to 9.14 m) long are considered with two to six stories in height. The comparison shows that the simpler beam model (with shear deformations) yields displacement and force results that are very close to the more complex finite element approach with a fine mesh. It is co ncluded that the beam model is an appropriate and accurate alternative to the more refined finite element method. T o provide adequate stiffness and resistance in precast, prestressed buildings against wind and seismic forces, concrete walls have been used successfully for more than 35 years. Vertical cantilever walls that are de- signed to receive lateral forces from diaphragms and trans- mit them to the ground are commonly termed shear walls. The forces in these walls (see Fig. 1) may often be predomi- nantly shear forces, though a slender wall will also incur significant bending. The total lateral displacement of a shear wall is the sum of the shear and bending deflections. These walls are placed at appropriate locations within and around the building perimeter to suit the architectural and functional constraints (see Figs. 2 to 5). In many cases, these walls have a constant cross section throughout their height or with negligibly small openings. During moderate and severe seismic events, including the recent Kobe earth- PCI JOURNAL

Comparison of Shear Wall Deformations and Forces Using Two Approaches

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