Distortions and changes in orientation of a 30° wye pile assembly were monitored in an attempt to improve our understanding of this critical connection in cellular cofferdams. Main cell, arc cell and common wall hoop tensions were simulated by applying axial loads to the three wye legs. Loads and displacements were monitored by a microcomputer aided data acquisition system. All of the behaviors studied exhibited some dependence on the ratio between the forces applied to the main and arc cell legs of the wye. Applied loads varied in magnitude and proportion, and the assembly re-oriented to new equilibrium positions. These positions were found to be predictable by solving three non-linear equilibrium equations of a statically determinate model. Common wall tension was observed to exceed main cell tension by 10-80% depending on the ratio of applied loads. Interlock load-deformation responses were measured for interlocks at which connecting piles were not coaxial. Wye angle deformations were found to be very small in the test loading range. The results of this investigation may be useful in developing parameters for and comparing results from finite element models of cellular cofferdams. / M.S.