The geological history analysis of the friction angle in transported soils and their importance in the bearing capacity of shallow foundations

Este trabajo muestra el estudio de la variabilidad del ángulo de fricción con el análisis de la historia geológica y su influencia en la capacidad de carga de cimentaciones superficiales. Esto se realizó con la generación de campos aleatorios del ángulo de fricción por medio de la técnica de matriz de descomposición para una distribución lognormal autocorrelacionada. Adicionalmente, para recrear la historia geológica se crearon los campos aleatorios de forma anisotrópica por medio de la matriz de giro con ángulos de 0, 45 y 90 grados. Posteriormente estos campos aleatorios fueron implementados en un modelo de elementos finitos de una zapata continua. El modelo constitutivo usado fue un modelo lineal elástico con criterio de falla de Mohr Coulomb. Lo anterior, para el entender la influencia de la historia geológica y la variabilidad del ángulo de fricción en la capacidad de carga de cimentaciones superficiales. Como resultados se muestran los pesos de la variabilidad del ángulo de fricción en la capacidad de carga y la influencia del buzamiento de este ángulo fricción en la capacidad de carga.This work shows the variability of the friction angle based on the geological history, over the bearing capacity of shallow foundations. This study was developed through the generation of random fields of friction angle using the matrix decomposition technique for a self-correlated lognormal distribution. In addition, to recreate the geological history, the anisotropic random fields were created using the rotation matrix with angles of 0, 45 and 90 degrees. Subsequently, these random fields were implemented in a finite element model of a continuous footing. A linear elastoplastic constitutive model was selected to represent stress-strain soil behavior together with the Mohr-Coulomb failure criteria. This last work was done in order to understand the influence of geological history and the variability of the friction angle in the bearing capacity of shallow foundations. Results include the weight of the variability of the friction angle in the bearing capacity and the influence of the dip over the friction angle and the bearing capacity.Peer Reviewe

Non Abelian TQFT and scattering of self dual field configuration

A non-abelian topological quantum field theory describing the scattering of self-dual field configurations over topologically non-trivial Riemann surfaces, arising from the reduction of 4-dim self-dual Yang-Mills fields, is introduced. It is shown that the phase space of the theory can be exactly quantized in terms of the space of holomorphic structures over stable vector bundles of degree zero over Riemann surfaces. The Dirac monopoles are particular static solutions of the field equations. Its relation to topological gravity is discussed.Comment: 13 pages, Late

Selection and scaling approaches of earthquake time-series for structural engineering applications: a state-of-the-art review

Selection and scaling of ground motion records have been recognised as one of the major sources of bias and uncertainty in the seismic assessment of civil engineering structures. This review paper provides a comprehensive description from a critical point of view of the scaling and selection approaches of earthquake motions for structural engineering applications, emphasising works conducted in the last decade. The outline of content within this review is organised as follows: (1) Earlier works (research done before 2010); (2) Code-based selection and spectral matching; (3) Probabilistic assessment based on intensity measures; and (4) Use of simulated signals as an alternative to ground motion selection and scaling. The aim of this paper is to provide a wide understanding of current research on the scaling and selection of earthquake motions for structural engineering applications; therefore, it may serve as a suitable reference in forthcoming investigations.This study has been partly funded by the STAND4HERITAGE Project that has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Program (Grant Agreement No. 833123), as an Advanced Grant. This work was also partly financed by FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020, and under the Associate Laboratory Advanced Production and Intelligent Systems ARISE under Reference LA/P/0112/2020

Analysis of buñuelos growth rate using 2K factorial design

Buñuelos are a traditional food not only in Colombia but in several parts of the world. They are prepared mainly with cassava starch, cornstarch, cheese, water or milk. The purpose of this work is to determine which factors (trademark, time, temperature, serving size) or interactions between them are important to achieve a major volume of the buñuelos. Thus, a 2k design is proposed to analyze the factors on the growth rate of buñuelos. The growth rate is calculated taking into account the buñuelos diameter before fried and after fried. The results indicate that the serving size has the principal effect on the response variable but followed by the trademark and some interactions between time and temperature

Selection and scaling validation of ground motions according to TBEC-2018 for the seismic assessment of masonry structures

This paper addresses the selection and scaling of earthquake time histories for analysing masonry structures' Out-Of-Plane (OOP) response according to the 2018 Turkish Building Earthquake Code (TBEC-2018) guidelines. Ground motion simulations are proposed for regions with limited seismic networks or lacking information regarding recorded accelerograms for large-magnitude events. Selection and scaling procedures are automatised according to the TBEC-2018 recommendations. The pre-selection is conducted according to specific seismological characteristics, and the optimal scaling factors of individual records are computed using a metaheuristic optimisation based on the Differential Evolution Method (DEM). Two sets of records (11 real and 11 simulated) are generated and used as input to conduct non-linear dynamic analyses. A U-shaped masonry prototype is adopted as a structural benchmark. The structural response is monitored with an emphasis on the OOP response.ERC -European Research Council(LA/P/0112/2020

Seismic assessment of typological masonry buildings using simulated ground motion records: A case study for Azores, Portugal

Earthquakes are the major causes of damage and loss to the built environment, including cultural heritages, monumental buildings, and historical centres. Many regions with predominant active tectonic plates and high seismicity lack recorded ground motion datasets regarding large-magnitude events or near-field records. Among them, the Azores islands in Portugal are the regions with high seismicity. The traditional buildings from the Azores are mainly constituted of rubble stone masonry, which represents one of the weakest materials once subjected to seismic loads. The seismic performance of buildings has recently increased, given the public awareness related to damage prediction and risk mitigation during earthquakes. This study uses the stochastic finite-fault ground motion simulation approach to simulate region-specific scenario earthquakes in the Azores Plateau at bedrock. Simulations are accomplished by considering the stochastic behaviour of input-model parameters in terms of source and path attenuation effects. As a result, the dataset includes a wide range of moment magnitude and source-to-site distance due to the rupture of active faults in the Azores Plateau. Structural models are simulated using an equivalent frame model. Subsequently, analytical fragility curves are derived for these structures using the generated ground motion datasets. Results reveal that the studied structures are vulnerable to seismic actions.ERC -European Research Council(LA/P/0112/2020

Larval performance and adult attraction of Delia platura (Diptera: Anthomyiidae) in a native and an introduced crop

Delia platura Meigen is an important pest in crops around the world. Its host range includes almost 50 species and it can develop in soil organic matter. In Ecuador, D. platura is a serious problem for the crop, Lupinus mutabilis Sweet (Chocho) and it also attacks broccoli (Brassica oleracea). After broccoli is harvested, crop residue is mixed with soil or collected and stored close to Chocho fields. The objectives of this study were to determine the adaptive responses of larvae reared on different hosts and whether D. platura females are preferentially attracted to germinating L. mutabilis seeds or broccoli residue. Accordingly, larval performance and attraction of female D. platura reared on broccoli residue and L. mutabilis seeds were evaluated. The number of larvae, pupae and adults were higher when reared on broccoli. Conversely, pupal weight was higher and time from larva to pupa, pupa to adult and total life cycle were longer in flies reared on L. mutabilis. Although D. platura developed more quickly on broccoli, L. mutabilis was also a good host since pupae were heavier compared with flies reared on broccoli. Delia platura females reared on broccoli preferred broccoli residue to L. mutabilis in an olfactometer. Volatiles from broccoli residue in soil may attract D. platura females and stimulate oviposition on L. mutabilis seeds. Environmentally benign production of L. mutabilis crops with minimal insecticide applications may require the elimination of fresh broccoli residue as fertilizer in soils where L. mutabilis is cultivated