Erudawn
Structural
- Apr 3, 2019
- 7
ACI 350.3-06 Sec R4.1.4 states that the effective fluid pressure shall be increased or decreased due to the effects of vertical acceleration, but it doesn't clearly specify under which vertical seismic direction it should be increased or decreased.
For instance, if I am considering a vertical earthquake force (EQv) in which the seismic inertia of the concrete structure is upwards, I imagine that the entire concrete structure moves upwards along with the base of the tank, while the contained liquid remains stationary, thereby increasing the downward fluid pressure acting on the base.
Does this mean that the effects of vertical acceleration on the contained liquid are always opposite to its effect on the concrete structure? (i.e., when the vertical effect of seismic on the concrete structure is upwards, its effect on the contained liquid is downwards, and vice versa).
For instance, if I am considering a vertical earthquake force (EQv) in which the seismic inertia of the concrete structure is upwards, I imagine that the entire concrete structure moves upwards along with the base of the tank, while the contained liquid remains stationary, thereby increasing the downward fluid pressure acting on the base.
Does this mean that the effects of vertical acceleration on the contained liquid are always opposite to its effect on the concrete structure? (i.e., when the vertical effect of seismic on the concrete structure is upwards, its effect on the contained liquid is downwards, and vice versa).