Seismic retrofit

Ok… I will talk about my wardrobe :) but give me a minute or two.

I just happened to have a wardrobe which is missing the back panel. It’s standing off the vertical with almost no lateral resistance. I thought, it just needs seismic retrofitting. I can calculate it for real structures so I should be able to actually do it for a simple wardrobe.

Seismic retrofit is basically designing a modification to an existing structure to make it able to withstand a given seismic intensity. There are many many strategies and techniques to do that for a real structure. But let’s stick to my wardrobe, it’s easier.

Usually you analyse the existing structure to check if there are any deficiencies that you should fix and which are the strategies that you can adopt to make the structure safer. For my wardrobe, the back panel was missing and the shelves were not properly connected to the lateral panels.

I thought that a better connection at shelves-level would help in providing a “diaphragm” action, which allows the lateral panels to work together in resisting lateral forces creating some kind of frame action. So I used duct tape to reinforce two of the shelves in the back. Unfortunately, the duct tape was not sticking properly and the effect was almost nothing.

So I thought, let’s go for duct tape-bracing. I created three diagonal braces with the duct tape and I put them on the back of the wardrobe. By doing this, the tensile bracing forces created a truss-like collaboration between the two lateral walls.

And ta-da! Now this guy is standing properly :)