An investigation is described into the effect of various combinations of the normal modes of vibration of cantilever shear wall structures on the maximum shears at flexural capacity. It is shown that the base shear can be much higher than would be derived by assuming a normal code lateral load distribution of sufficient magnitude to cause flexural yielding. The results of elastic normal mode response spectrum analyses of a 10-storey building considering several structural variables are presented in terms
of envelope values of the ratio of maximum base shear at flexural
capacity to that assuming a code lateral load distribution. The same effect is investigated with a series of step-by-step numerical integration dynamic analyses of cantilever wall structures responding inelastically to a range of earthquakes. On the basis of the results suggestions are made for the shear design of cantilever walls.