Effect of vertical contraction joints in concrete arch dams

The vertical joints between the blocks of concrete in arch dams allow for contraction as the concrete cools during construction. Linear analyses, which ignore the presence of these joints, indicate large horizontal tensile stresses near the joints particularly when seismic loading is included. The U.S. Bureau of Reclamation is studying the nonlinear behavior of these vertical joints by making comparisons between parallel linear and nonlinear analyses of East Canyon Dam. This paper reports on the use of ADINA's gap element to model the contraction joints. The nonlinear analysis shows decreased values of the horizontal tensile stress at the expense of larger compressive stresses and increasing values of vertical tensile stress.