Abstract: A pure fixed-head ~zero-rotation! condition at the top of a group of laterally loaded piles is seldom achievable in the field, = j)5kY`
even when piles are installed in a group that is ‘‘rigidly’’ constrained by a stiff concrete pile cap. Assuming complete fixity during design "}*5'e.*
~zero rotation at the pile head! can result in underestimated values of pile-head deflection, and incorrect estimates of the magnitude and u]0{#wu;g
the location of maximum bending moments. A simple and practical approach is presented for estimating the moment restraint that is ]WF r5
provided by the pile cap at the top of a pile group. The moment restraint, represented by the rotational restraint coefficient (KMu), serves Z #uxa
as a boundary condition for analyzing groups of laterally loaded piles. Full-scale field tests performed on two pile groups with concrete ~xPU#m<
pile caps show that the proposed method for estimating rotational restraint provides results that are in good agreement with measured field HV2 1=W
performance.
