Abstract
During an earthquake, perimetral and vertical joint opening affects the seismic response of concrete arch dams by releasing the tensile stresses and redistributing the internal forces of the dam. Although the mechanism of these two types of joint openings is the same, their effects on the response of the dam are different. Perimetral joint opening, in the contact area of dam body and foundation, releases the relatively high tensile cantilever stresses at the base of upstream face and increases the radial displacement of the dam toward downstream direction, whereas vertical joint opening between cantilevers of the dam releases the arch tensile stresses and cantilever action resists the internal forces by bending toward upstream which results an increase in cantilever compressive stress at the base of upstream face.
