PULVINO and Peripheral Joint Effects on Static and Seismic Safety of Concrete Arch Dams

One of the methods in limiting tensile stresses in arch dams and removal stress concentrations at dam-foundation interface is setting the dam body on a concrete saddle called PULVINO. In the present study, effect of PULVINO and peripheral joint on the static behavior and seismic performance of arch dams are investigated. DEZ dam with 203m height was selected as case study and all contraction joints of the dam body were modeled using discrete crack approach based on as-built drawings. Also, surrounding rock was modeled as a mass-less medium tied to PULVINO. The dam-reservoir-foundation system was analyzed under static loads accounting for stage construction effects, hydrostatic and thermal loads and then the provided numerical model was excited using near- and far-field earthquake ground motions. It was found that modeling peripheral joint between saddle and the main dam body changes the direction of principal stresses and their distribution patterns and safety of the system is improved. In addition, over stressed surfaces on faces of the dam body decreased in comparison with the model without peripheral joint.