Stress distribution around an unusually large opening in a dam which is located nearer than one times the width or height of an openinq to the face of a dam is determined by means of photo-elastic model studies for three different prevailing loading conditions including earthquake effect. Further, a method of designing the optimum reinforcement around an opening utilising stress curves from model studies has been described. The method presented obviates the necessity of resorting to empirical or semiempirical methods of designing openings based on assumptions.
