Case Study: Construction Method, reinforcement selection and fire engineering

Post date: Oct 17, 2016 4:15:21 AM

These are photos of the fire aftermath when Syn Lee Fah Superstore at Sandakan caught fire. What are the tale-tell signs that you may interpret from such incident?

First, the fire is most likely to be of medium intensity. Although the steel structures buckled, it is less likely due to high intensity fire. The buckling of the structure is most likely due to the self weight and series of design issues. From the photo, the main truss was not designed appropriately where the webs are too small to withstand the desired capacity in order to function optimally. Another sign of medium intensity fire is the carbon staining around steel structures.

Second, the collapsed of this building is due to inappropriate extension work(s). The extension did not consider the design capacity where the unrestrained columns failed when encountered moment force when the main truss bolted to the column rotated with downward force.

Third, with careful eyes, you can see the columns and stiffeners on the second/third photo. The main reinforcements for the column is presumed to be smaller than anticipated under such loading. It has the same size with the nominal link or stirrups.

Fourth, with careful eyes, the failure of this building is due to method of construction for these columns. It is likely that there is a cold joint for columns at the height of 750mm - 900mm. Untreated cold joint is dangerous when it is the area which initiate tensile stress under multiple loadings.

** This is an educational article and should be use as it is.