October 2011, Earthquake Engineering Research Institute.
There is a strengthened school building in Ercis. This is a 4-story RC frame with original and added shear walls. Non-structural damage is moderate. Original frame of the structure have bad quality concrete and workmanship.
Original shear walls of the structure along the north-south direction has honeycomb shear cracks in the first three stories with decreasing intensity. Cracks at the base are about a mm wide. Added shear walls for strengthening along the north-south direction show signs of separations at the upper beam and column interfaces for the lower two stories.
Figure 1. 4-story school building that is strengthened for earthquake demand.
Figure 2. Honeycomb shear cracks at the existing shear wall.
Figure 3. Separation cracks at the added shear wall-existing frame interfaces.