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GEOMETRICALLY NONLINEAR DYNAMIC ANALYSIS OF CONCRETE ARCH DAMS

In this research, suitable models for large deformation analysis of concrete arch dams and other similar concrete structures are investigated and by considering arch dam special features and properties, proper model for its large displacement analysis is presented. Major abilities of the prepared computer code in geometric nonlinear analysis of structures is introduced and after its basic verifications a nonlinear analysis of the Morrow Point dam using the Saint-Venant -Kirchhoff model for large displacements is carried out under the case of an intensive ground motion. Foundation is considered as rigid and fluid-structure interaction is approximated by the modified Westergaard added mass concept. It is indicated that considering large deformation effects reduce the displacement response of dam. This reduction is about 8 % in respect to linear dynamic analysis in peak responses. On the other hand, large deformation effects reduce compression stresses and increases tensile ones. Values of these changes are about 9 % for compression and 6% for tension. It seems that for large seismic loads a consistent inclusion of this type of nonlinearity is necessary in order to grasp a proper image of concrete arch dam dynamic real response