Estudio teórico y experimental del refuerzo mediante recrecido de encepados rígidos de hormigón armado
(English) The need to strengthen foundations in existing structures has become increasingly important, driven by the aging of constructions and the growing demand for enhanced structural capacity, whether due to changes in use or updates to regulatory standards. In the case of rigid RC foundations,...
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| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2024 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | español |
| OAI Identifier: | oai:upcommons.upc.edu:2117/456031 |
| Acceso en línea: | https://hdl.handle.net/2117/456031 https://dx.doi.org/10.5821/dissertation-2117-456031 |
| Access Level: | acceso abierto |
| Palabra clave: | 624 - Enginyeria civil i de la construcció en general Àrees temàtiques de la UPC::Enginyeria civil |
| Sumario: | (English) The need to strengthen foundations in existing structures has become increasingly important, driven by the aging of constructions and the growing demand for enhanced structural capacity, whether due to changes in use or updates to regulatory standards. In the case of rigid RC foundations, these often behave as D-regions, areas where stress and deformations do not follow a linear pattern and require specialized design approaches. While numerous studies have focused on the reinforcement of B-regions, research addressing the behavior of D-regions, such as rigid foundations, remains limited. This thesis addresses this gap by analyzing the behavior and reinforcement techniques through the enlargement of rigid reinforced concrete pile caps, a solution that increases their structural capacity. Special emphasis is made on the application of the Strut-and-Tie Method (STM), an approach particularly suited for D-regions, as it simplifies the non-linear behavior of stresses in these areas, facilitating the understanding of the structural mechanisms involved. The research combines a comprehensive literature review with an experimental campaign, in which reinforcement of rigid RC pile caps through enlargement was evaluated. The experimental tests and Non-Linear Finite Element Analysis (NLFEA) helped study the structural behavior of the pile caps in different configurations. The analysis of the results shows that enlargement is an effective technique to improve the structural capacity of foundations, although its success depends on factors such as the quality of the joints between the new and existing concrete and, to a lesser extent, the arrangement of secondary reinforcement. Additionally, the behavior in the Serviceability Limit State (SLS) was analyzed, and strut-and-tie models were proposed, with concrete ties whose tension varies with the evolution of crack widths. These models are capable of coherently explaining the behavior observed experimentally across the entire load range. Following the presentation of the experimental results, different design methodologies are compared, and the use of STM for reinforced pile caps is proposed, with a particular focus on verifying the struts crossing the joints between the original and enlarged sections. The findings are not only applicable to various structural scenarios but also establish a solid foundation for future research on the reinforcement of D-regions, making a significant contribution to the preservation and enhancement of existing structures. |
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