Loading ...With zero damage .
That includes a 6.8 in Jan. 2024 , with epicenter about 25 miles away .
Concrete is very strong in compression , but weak in tension .
The home I was in has a concrete second floor and a 500 gallon water tank above that.
The rebar reinforced columns support the weight above the concrete first floor ensure maintaining compressive loading continuously , even during the seismic event .
In bending unloaded columns , the momentary outside of the bending column is in tension and cracks form , then a moment later the opposite side becomes tensile . The column fails and the structure collapses . The trick is maintining constant loading from above via gravity .