ACI 350.3-06 Seismic Design of Liquid-Containing Concrete Structures and Commentary

ACI 350.3-06 Seismic Design of Liquid-Containing Concrete Structures and Commentary. 5.3—Dynamic force distribution above base R5.3 5.3.1—Rectangular tanks R5.3. Walls perpendicular to the ground motion being investi- The gated and in the leading halt of the tank shall be dynan loaded perpendicular to their plane (dimension B) by may the walls own inertia force P1,, one-halt the impulsive LI 986 force P1. and one-half the convective force Pr,. Walls perpendicular to the ground motion being investigated and in the trailing half of the tank shall be loaded perpendicular to their plane (dimension B) by the walls own inertia force Pa,, one-half the impulsive HL force P1 one-half the convective force P, and the dynamic earth and groundwater pressure against the buried portion of the wall. Walls parallel to the direction of the ground motion being investigated shall be loaded in their plane (dimension L) by: (a) the wall’s own in-plane inertia force Pj., and the in-plane forces corresponding to the edge reactions from the abutting wall(s). Superimposed on these lateral unbalanced forces shaH be the lateral hydrodynamic force resulting from the hydrodynamic pressure due to the effect of vertical acceleration Pvy acting on each wall. 5.3.3—Circular tanks The cylindrical walls of circular tanks shall be loaded by the wall’s own inertia force distributed uniformly around the entire circumference; one-half the impulsive force P, applied symmetrically about 0 = 0 degrees and acting outward on one half of the wall’s circumference, and one- half P1 symmetrically about 0 = 180 degrees and acting inward on the opposite half of the walls circumference; one-hail the convective force P acting on one-half of the wall’s circumference symmetrically about 0 = 0 degrees and one-half P symmetrically about 0 = 180 degrees and acting inward on the opposite half of the walls circumference; arid the dynamic earth and groundwater pressure against the trailing half of the buried portion of the wall. Superimposed on these lateral unbalanced forces shall be the axisymmetric lateral hydrodynamic force resulting from the hydrodynamic pressure Pvy acting on the tank walL 8.1—General Dynamic earth pressures shall be taken into account when computing the base shear of a partially or fully buried liquid-containing structure and when designing the walls. The effects of groundwater table, if present, shall be included in the calculation of these pressures. The coefficient of lateral earth pressure at rest K o shall be used in estimating the...