Abstract

The structural integrity of concrete dams is essential to guarantee the safety of downstream communities and the reliability of water resources, hydropower generation and flood control. Because of the brittle behavior of concrete, dams may already exhibit cracking during the construction phase and under normal operating conditions, and this susceptibility becomes even more pronounced when the structure is subjected to high-intensity forces due to exceptional events such as earthquakes. These cracking phenomena reduce stiffness and modify the distribution of internal stresses; however, they do not necessarily imply a deterioration in the structure's overall performance. In fact, several dams still operate safely despite cracking. Nevertheless, accounting for the concrete cracking in the numerical simulations is important for evaluating structural safety and studying the genesis and evolution of cracks.
The cracking behavior of concrete dams under seismic loading is investigated by comparing the results of two different modeling approaches available in Abaqus: the Extended Finite Element Method (XFEM) and the Concrete Damaged Plasticity model (CDP), more experienced by the authors and widely used on concrete dam applications. Several case studies are considered, both two-dimensional (Koyna Dam, India, and Pine Flat Dam, California) and three-dimensional (a large double-curvature arch dam, ideally inspired by Tzakov Kamak Dam, Bulgaria).
The performed analyses showed that the XFEM can be adopted as a complementary strategy for the structural evaluation of concrete dams, enabling a more accurate representation of the physical nature of crack development.
 

PDF Slides

Speakers

In 2013, Martina Colombo obtained a Master's degree in Civil Engineering, specializing in Building Engineering, with a grade of 110/110. Her thesis focused on static and seismic analyses of a buttress gravity dam.

In 2019, Martina obtained a PhD cum laude in Structural, Seismic and Geotechnical Engineering from the Politecnico di Milano, completing a research study titled "A"regularized chemo-mechanical damage model for structural analyses of concrete dams in the presence of Alkali-Silica Reaction".
After a parental break, during which she became a mother of three children, Martina started working in 2022 as a Researcher as part of the Renewable Energy Group of Sustainable Development and Energy Sources department at RSE (Ricerca sul Sistema Energetico), a company operating in the renewable energy sector, currently owned by GSE (Gestore Servizi Energetici). The company is involved in national and international funded research programs and contracts in the electro-energy sector.

Martina's work in dam engineering involves activities funded by the Research Fund for the Italian Electrical System, as well as projects commissioned by third-party concessionaires, focusing on the assessment of the structural and seismic behavior of dams in accordance with current regulations. The software most frequently used in her work includes Abaqus and CANT‑SD, the latter developed in-house at RSE.

@MC 
Researcher,  RSE Ricerca sul Sistema Energetico 
 

Giorgia Faggiani is a Senior Researcher at Ricerca sul Sistema Energetico – RSE S.p.A. She holds a MaMaster'segree in Building Engineering from the Politecnico di Milano (2000) and has more than twenty years of experience in the field of dam engineering, with a particular focus on concrete dams. Her professional activity spans both research and applied consultancy for the safety assessment of hydroelectric infrastructures.

Giorgia has expertise in finite element simulations for the safety assessment of concrete dams, including nonlinear constitutive models, contact interaction, fluid-structure and soil-structure dynamic interaction, response spectrum analyses, time‑history analyses, and assessments of structural behavior under aging or expansive phenomena such as Alkali–Aggregate Reaction (AAR). Most of the activities are in the research field and consist of the study and the development of innovative (both advanced and expeditious) methods and approaches to improve the safety operation and management of dams. Consulting activities consist in FEM numerical analyses for the seismic safety assessment of concrete dams and for the detection and forecast of the effects of the AAR reaction.

Over the past years, Giorgia has contributed to several scientific publications presented at international conferences in dam and earthquake engineering.

Giorgia Faggiani
Senior Researcher,  RSE Ricerca sul Sistema Energetico