The fundamental concept behind ACI 350.3 is that a tank full of water does not act as a rigid mass. During an earthquake, the water moves in two distinct ways, creating two different types of forces:

: For liquid-containing structures, special considerations might include leakage control, watertightness, and performance under seismic loading.

ACI 350.3-06 provides specific requirements for the earthquake-resistant design of concrete liquid-containing structures. While general building seismic codes (like ASCE 7 or the International Building Code) focus on occupant safety, ACI 350.3 focuses on .

You might ask: Why focus on the 2006 version when newer editions exist (ACI 350.3-20)?