Report - PEER - University of California, Berkeley

5.1 Flexural Structural WallsAn example of the behaviour of flexural walls is shown in Figure 8. Initially the wallstiffness is high. Yielding of the steel reinforcement in ductile flexural walls occursat drift values of approximately 0.8%. The drift limits corresponding to variousdamage states of ductile flexural walls are listed in Table 2.5.2 Squat Shear WallsThe relationship between damage and drift ratio for squat walls is shown in Figure 8.Initially under low levels of load, the behaviour of the squat wall is the same asductile flexural walls. However, when shear cracks occur and are not arrested, thewall stiffness degrades rapidly reflecting a substantial increase in damage leading toabrupt failure. In the case of squat walls, it was experimentally observed that damageindex of 0.3 represents the limit of repairable damage. This limit corresponds torelatively low drift ratio value of 0.4%. The steel yield point is normally not reachedbefore shear failure occurs. The drift limit corresponding to various states of damageof squat shear walls are listed in Table 2.10.8Damage index0.60.40.20Squat shear wallFlexural wall0 1 2 3Drift ratio %Figure 8. Shear and flexural behaviour of walls (Khalil and Ghobarah 2003).331