Investigations of the impact of considering different numerical modelling techniques for determining seismic damage at the dam-foundation interface of the stepped abutment of a concrete gravity dam: A case study on the Beni-Haroun Dam

This paper investigates how accounting for contact conditions and a step abutment in the foundation affects the seismic damage behaviour of concrete gravity dams. For this purpose, a pushover analysis was conducted utilising two distinct calculation models based on continuum damage mechanics. The first model uses a continuous mesh between the dam and the soil foundation without modelling any discrete interfaces, while the second considers the dam and soil meshes separately with contact relations. To improve accuracy, the numerical simulations were conducted for each case with three different damage models. The results indicate how considering contact conditions has a significant impact not only on the overall seismic response but also on the distribution and progression of the damage field in the dam. More precisely, the areas where damage occurs in the vicinity of the foundation zones differ between these two models. The first model results indicate damage first appearing near the heel, while with the second model the damage begins near the abutment. This is demonstrated using the Beni-Haroun gravity dam as a structural case study.