LBA LIA – English Learning Center

The building was a 4-story reinforced concrete frame building with brick infill.  After the September 30, 2009 earthquake, the first and second story of the building collapsed, resulting in 4 total fatalities.  Based on local accounts, 11 were trapped in the collapsed building after the earthquake but 7 of them were able to be saved. 

The typical beams and columns sizes used in the building are very small for supporting such heavy 4-story building.  The typical interior columns were 16”x18” and the typical interior beams were 14”x18”.  Notice that the partitions are brick walls, adding a lot more mass to the building.  The reinforcement used throughout the building are smooth rebars.  The concrete columns seem to lack adequate confinement for ductile detailing (Figure 6).  “Short hooked anchors” (Figure 7) are also very common throughout the building.  Notice that the short anchorage length does not satisfy the 12db requirement per ACI.

Figure 1. Front view of the collapsed building.		Figure 2. Side view of the collapsed building.	Figure 3. Back view of the collapsed building.
Figure 4. Third story columns shear failure at the stairs.		Figure 5. The beams and columns sizes are very minimal for such a heavy 4-story building.	Figure 6. Damaged joint exposing lack of confinement from the minimal ties.

Figure 7. The hooked anchor commonly found in damaged buildings, which do not provide adequate anchorage length.