has presented a useful and interesting paper and, as the author suggests, research is needed into low walls at capacity in order to understand the load mechanism, cracking patterns and damping factors. Mr. Armstrong illustrates his example of shear in low walls by dividing his wall into elements separated by 45° cracks and then considers the forces across the crack which appear to be mainly the nominal wall steel. My own philosophy in the detailing of low shear walls is to ensure that the area

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... t and adjacent to the top of the wall contains sufficient reinforcement to transfer all applied code loads back to the leading edge of the wall and to tie the elements together at that level. Arch action will then carry these forces down to the base.