Lateral‐Load Analysis of Frame Stagings for Elevated Water Tanks

Abstract

While carrying out an approximate lateral‐load analysis of moment‐resisting tank stagings, it is normal to assume a shear distribution in the columns; this leads to significant inaccuracies. It is shown that due to symmetry and simple configuration, such an assumption need not be made. In the proposed procedure, axial force in columns is obtained assuming it is proportional to the distance of the column from the bending axis of staging, and taking into account the shift in inflection point in the end panels due to the flexibility of girders. The rest of the unknown forces are computed by using equations of static equilibrium and by assuming the location of the points of inflection. It is possible to obtain simple closed‐form expressions for design forces and moments in the members. Such expressions may prove useful in approximate analysis of the tank stagings. Analysis of four practical stagings shows that the proposed procedure is significantly more accurate than the procedures still prevalent in many books and that the accuracy obtained by the proposed procedure is adequate for design.