Investigadores externos

Methodological framework for integrating structural health monitoring and digital-twin models for seismic assessment of heritage buildings: Case study of Basilica Maria Auxiliadora, Lima, Peru

Wed, 01 Jan 2025 00:00:00 GMT

Methodological framework for integrating structural health monitoring and digital-twin models for seismic assessment of heritage buildings: Case study of Basilica Maria Auxiliadora, Lima, Peru Aroquipa Velásquez, Héctor; Hurtado Chaparro, Álvaro Iván; Ángel, Christiam This study proposes a methodological framework for integrating structural health monitoring (SHM) systems with numerical digital twin (DT) models for the seismic assessment of heritage structures. This approach is being implemented within smart cities, focusing on intelligent circular resilience. The process begins in the physical world by recording data through strategically placed sensors distributed throughout the evaluated structures. Afterwards, the virtual world refers to the development of numerical models that capture the structural performance of the building while considering specific features to simulate the original one. The interconnection of both sides requires exhaustive and detailed cross-validation to ensure an established level of reliability, often based on the expected accuracy and limitations. Nevertheless, extending this process to heritage buildings demands a more sophisticated approach, designed to identify and classify discrete damage levels, and involves establishing proper threshold limits for an early warning/alarm system. This paper presents a methodology focused on the virtual implementation of these processes, aiming to integrate such technologies effectively. The case study is a religious monument that has been standing for over a century, located in a high seismic hazard zone in Lima, Peru. Numerical models were developed using 3DEC and SAP2000 software to capture the building's dynamic response, including modal and time-history analyses for a set of 34 seismic ground motion records. The results were used to identify susceptible zones and the location of sensors. Further recommendations address the challenges encountered in implementing this approach and outline the next steps, including sensor deployment and validation against experimental models.

Towards smart Cities: Foundational methodology for implementing intelligent circular resilience in heritage buildings through structural health monitoring and digital-twins – Part A

Wed, 01 Jan 2025 00:00:00 GMT

Towards smart Cities: Foundational methodology for implementing intelligent circular resilience in heritage buildings through structural health monitoring and digital-twins – Part A Aroquipa Velásquez, Héctor; Hurtado Chaparro, Álvaro Iván; Murga, Christian; De La Cruz, Ronal; Tarque, Nicola The relentless technological evolution is reshaping Disaster Risk Reduction (DRR), fostering innovative strategies in the context of smart cities. This paper explores the integration of advanced technologies—specifically the Digital Twin (DT) system—within Structural Health Monitoring (SHM) frameworks. This integration requires an efficient algorithm capable of real-time data processing, filtering, and large-scale analysis. The study introduces the concept of Intelligent Circular Resilience (ICR) as a novel DRR-oriented methodology tailored to the unique challenges of heritage buildings. ICR-SHM consists of six stages: Building System Characterization, Virtualization, sensor-based data retrieval and analysis, DT model updating, results generation, and feedback. SHM plays a central role in this framework by linking virtual and physical domains, thus reducing maintenance costs and extending service life through its adaptability, cost-effectiveness, and ability to operate under limited data availability. As the full implementation of the framework is extensive, this paper focuses on the early-stage development and application of the first two stages: the geometric and historical characterization and virtualization of a centennial religious monument in Lima, Peru. To this end, a topographic survey using a 3D laser scanner was conducted, followed by the development of a Building Information Model (BIM) to assess and validate structural alterations since the original construction. Subsequently, a seismic damage assessment was performed using historical earthquake reports, event catalogues, and ground motion records. Results reveal a clear correlation trend between reported damage and seismic events. The study encourages the advancement of numerical–experimental integration, optimization of sensor placement for DT correlation, and enhancement of SHM performance.

Maximum valorization of red prickly pear peels through green extraction techniques of bioactive compounds and cellulose microfibers

Wed, 01 Jan 2025 00:00:00 GMT

Maximum valorization of red prickly pear peels through green extraction techniques of bioactive compounds and cellulose microfibers León Félix, Lizbet; Bustamante Bernedo, Milagros Sofia; Valdez Chirinos, Irene; Huamán Castilla, Nils Leander; Ponce Álvarez, Silvia This study evaluated the effect of particle size (375–116 μm) on the chemical composition of red prickly pear (Opuntia ficus-indica) peels, as well as on the ultrasound-assisted extraction of bioactive compounds using an ethanol:water (40,60 v/v) solvent at 30 °C. Residual biomass was used to obtain cellulose fiber (CF) suspensions via alkali hydrogen peroxide pretreatment and mechanical homogenization. Smallest particle (< 188 μm) significantly enhanced antioxidant activity (6.5 mg of gallic acid equivalents/g dw, IC50, 0.7 mg/mL). X-ray diffraction confirmed reduced crystallinity of CF, with the highest crystallinity index (61 %) in particles 116 μm. Infrared spectroscopy identified the presence of phenolic, carboxylic acid, and betalain compounds in the extract and confirmed the removal of non-cellulosic components. Morphology analysis showed network of CF with diameters around 180 nm for the smallest particles. Thermal analysis indicated that the thermal decomposition of CF occurs at 350 °C, higher than raw peel (300 °C), confirming improved thermal stability.

Exploring the urban systemic scenarios of improving socioecological conditions in an informal settlement of a developing country with a system dynamics model

Wed, 01 Jan 2025 00:00:00 GMT

Exploring the urban systemic scenarios of improving socioecological conditions in an informal settlement of a developing country with a system dynamics model Acevedo De los Ríos, Alejandra; Chumpitaz Requena, Favio Rafael; Rondinel Oviedo, Daniel Ricardo; Cárdenas Mamani, Úrsula; Redondo Johan, Manuel Informal settlements (IS) present a complex system of social, economic, and ecological interactions that arise spontaneously and unplanned in urban areas and require a forward-looking and comprehensive approach to address their socio-ecological interactions. Moreover, an IS is conceptually considered a sub-system within a broader urban system, interacting with and influenced by internal and external factors. This study aims to model these interactions and factors using System Dynamics (SD), with the objective of simulating and evaluating decisions, actions, and their dynamic consequences concerning settlement consolidation (e.g., enhancing and optimizing urban areas) and improving women's access to formal employment opportunities. Consequently, a 10 year framework SD model for five scenarios was developed, including: (S0) Business as Usual (BAU); (S1) Time quality scenario; (S2) Women in formal employment scenario; (S3) Circularity scenario; and (S4) Comprehensive scenario. The results indicate that the implementation of individual solutions, such as improving the quality of men's working time (without overtime), formal employment for women (equalizing income conditions with men), water circularity (use of fog catchers and the recycling of greywater as a supply), and organic waste management (organic compost for urban gardens and the implementation of urban agriculture), does not fully leverage potential synergies. However, a comprehensive scenario that combines individual solutions jointly achieves a decrease in the time needed to improve women's conditions in formal employability (47.5 %), which is related to the settlement consolidation process. These findings provide insight into possible action strategies and policy implications for effectively addressing the challenges associated with informal settlements.