Response of shear wall-frame buildings to skewed wind load

Abstract

Results of an analysis performed on two 4-story shear wall and frame buildings are studied to determine the response of the buildings to wind load from any one of several directions. The two buildings, one of square plan and the other of rectangular plan, are designed to represent typical shear wall-frame buildings. The interaction between the wall and frame under lateral load is discussed to lay the groundwork for the interpretation of results found from the analysis. By modifying analytical techniques derived by others, a model is obtained suitable for analysis by computer with loads representing those which would exist under wind from any one of several directions. The analysis performed is static, elastic, and linear with internal member forces and deflections as the output data. Data from the model analysis are then used to determine member forces and stresses of the actual buildings as well as to study their deformation characteristics. Results show that maximum stresses due to lateral load in several different portions of the shear cores of both buildings are due to wind from different directions depending on which section of wall is considered. In the square building, the maximum stress caused by wind from an angle of 45 degrees to the major axes of the building is 25 percent greater than the maximum stress caused by wind perpendicular to a building face, but the 45-degree stress governs the design of only 14 percent of the shear core. Design of other sections of the square shear core are controlled by stresses caused by wind from other directions. Similar results are seen in the shear core of the rectangular building. Differences in the manner in which two different perpendicular frames interact with the shear core in the rectangular building is found to cause the deformation of the building under skewed wind load to exhibit a non-planar characteristic of small magnitude. The gravity load sizes of the beams and columns in the frames of both buildings are adequate to resist all skewed wind loads. Recommendations for areas of additional study are made.