Obras y proyectos最新文献

{"title":"Modelling steel-concrete interaction using the extended finite element method","authors":"R. Gutiérrez, L. Stempniewski, W. Fleming","doi":"10.4067/S0718-28132018000200006","DOIUrl":"https://doi.org/10.4067/S0718-28132018000200006","url":null,"abstract":"espanolEl metodo de los elementos finitos extendidos (X-FEM) se emplea como alternativa para la modelacion de la union entre el refuerzo y el hormigon circundante en estructuras de hormigon reforzado, ya sea a traves de barras de refuerzo, fibras u otros. La interfaz de los materiales compuestos introduce una discontinuidad, y por lo tanto puede ser modelada numericamente a traves de X-FEM. Este metodo es capaz de modelar discontinuidades sin modificar la discretizacion mediante la adicion de nuevos grados de libertad a la aproximacion estandar de elementos finitos. Se presentan los elementos de union (o cohesivos) para ser comparados con la alternativa propuesta. Los resultados se comparan tambien con soluciones de referencia, mostrando una buena correspondencia. EnglishThe extended finite element method (X-FEM) is used as an alternative for the modelling of the bond behaviour between reinforcement and the surrounding concrete in reinforced concrete structures, through either reinforcing bars, fibres or others. The interface of composite materials introduces a discontinuity and, therefore, can be numerically modelled using X-FEM. This method is capable to model discontinuities without modifying the discretization by the addition of new degrees of freedom to the standard finite element approximation. Bond elements (or cohesive elements) are presented in order to be compared with the proposed alternative. The results obtained are also compared to reference solutions, showing a good agreement.","PeriodicalId":391731,"journal":{"name":"Obras y proyectos","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132203346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transient flow analysis using the method of characteristics MOC with five-point interpolation scheme","authors":"J. Twyman","doi":"10.4067/s0718-28132018000200062","DOIUrl":"https://doi.org/10.4067/s0718-28132018000200062","url":null,"abstract":"espanolSe muestra una version original del Metodo de las Caracteristicas (MC) de 2do orden que trabaja con un esquema de interpolacion de cinco puntos, valido para resolver las ecuaciones diferenciales parciales hiperbolicas y cuasi-lineales que describen el fenomeno del flujo transiente en redes de tuberias. Se comparan los resultados obtenidos por el MC 2do orden y la solucion exacta (MC 1er orden). Se demuestra que el MC 2do orden permite obtener resultados cercanos a los exactos dentro de una amplia gama de numeros de Courant. EnglishAn original 2nd-order Method of Characteristics (MOC) which it works with a five-point interpolating scheme valid for solving the hyperbolic and quasilinear partial differential equations that describe the transient flow phenomenon in pipelines is shown. The results obtained by both MOC 2nd-order and exact solution (MOC 1st-order) are compared. It is shown that MOC 2nd-order allows obtain near-to-exact results within a wide range of Courant numbers.","PeriodicalId":391731,"journal":{"name":"Obras y proyectos","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116020451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estudio experimental del efecto de la excitación basal y grado de saturación en las presiones de poros bajo una presa de tierra","authors":"M. Pasten, I. Salazar","doi":"10.4067/S0718-28132018000200053","DOIUrl":"https://doi.org/10.4067/S0718-28132018000200053","url":null,"abstract":"espanolSe investiga la variacion de las presiones de poros y el grado de saturacion en regimen transiente bajo una presa de tierra cuando dicha estructura es sometida a excitaciones dinamicas basales. Se construye un modelo fisico en el laboratorio de una presa de tierra a escala reducida (1:200). Se utilizan rangos de frecuencias de 3 a 10 Hz, direccion vertical y horizontal, y funciones seno, coseno y triangulares para representar la excitacion dinamica basal de la estructura. El control del proceso experimental es llevado a cabo con el registro continuo de las presiones de poros, junto con un balance hidrico general que permite controlar tanto la capacidad de infiltracion del sistema como el almacenamiento interno de agua y caudal de salida. Se obtienen resultados de presion de poros que reflejan la magnitud de la oscilacion piezometrica. Se encontro que las presiones de poros presentan mayores valores para un alto grado de saturacion del medio y para bajas frecuencias de excitacion. Ademas, se asocian cambios permanentes de la presion de poros debido a sobrecargas y succiones producidas en la interfaz presa-suelo de fundacion, como consecuencia de las excitaciones basales impuestas. EnglishThe pore pressure variation and the degree of saturation in a transient regime under an earth dam structure containing liquid are investigated, when subjected to basal dynamic excitations. A scaled physical model (1:200) of an earth dam is built. Frequency ranges between 3 and 10 Hz, in the vertical and the horizontal direction are used. Sine, cosine and triangular functions are used to represent the basal excitation of the structure. The experimental control process is carried out with the continuous measurement of the pore pressure along with a general hydrological balance, which allows controlling not only the infiltration capacity of the system but also the internal storage of water and effluent flow. Results of pore pressure represent piezometric level magnitudes. It was found that larger pore pressure values occur with the increase of the medium degree of saturation and low excitation frequencies. Also permanent changes in pore pressure due to surcharges and suction produced in the dam-foundation soil interface are observed, as a consequence of the imposed ground excitations.","PeriodicalId":391731,"journal":{"name":"Obras y proyectos","volume":"301 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113959024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Uso de agua de rechazo de plantas depuradoras en la fabricación de hormigones","authors":"Amin Nazer, A. Guzmán, Luis Bolados, Luis González, O. Pavez","doi":"10.4067/S0718-28132018000200021","DOIUrl":"https://doi.org/10.4067/S0718-28132018000200021","url":null,"abstract":"espanolLa Region de Atacama presenta ciclos de escasez hidrica que afectan tanto a la poblacion como a los sectores productivos, los que demandan ingentes cantidades de agua potable para su desarrollo. Con el proposito de disminuir la presion sobre el recurso hidrico, se incentiva al ahorro del agua potable y/o la reutilizacion de aguas grises domiciliarias y aguas industriales. En este contexto, la utilizacion de agua de rechazo proveniente de los procesos de purificacion de agua salobre, se presenta como una buena alternativa al agua potable en la fabricacion de morteros y hormigones. El presente estudio evalua el comportamiento mecanico del hormigon conteniendo agua de rechazo generada en los procesos de depuracion por osmosis inversa e intercambio ionico. Para ello, se caracterizaron 4 tipos de agua: agua potable (control), agua de rechazo del proceso de osmosis inversa utilizado en la produccion de agua purificada para la bebida; agua de rechazo tanto del proceso de intercambio ionico como del proceso de osmosis inversa, ambos del Hospital Regional de Copiapo, Atacama, Chile. Posteriormente, se fabricaron diferentes muestras de hormigon conteniendo los 4 tipos de agua y se evaluo su resistencia a la compresion a las edades de 7 y 28 dias. Los resultados mostraron que, en todos los casos, los hormigones fabricados con agua de rechazo alcanzaron mayores resistencias a la compresion que la muestra control. De los resultados del estudio, se puede concluir que el uso de agua de rechazo en la fabricacion de hormigones, puede ser una conveniente alternativa para la construccion en zonas aridas. EnglishThe Atacama Region presents cycles of water scarcity that affect both the population and the productive sectors, which demand huge amounts of drinking water for its development. In order to reduce the pressure on the water resource, it encourages the saving of drinking water and/or the reuse of sewage and industrial waters. In this context, the use of waste water from the brackish water purification processes is a good alternative to drinking water in the manufacture of mortars and concretes. The present study evaluates the mechanical behaviour of the concrete containing waste water generated in the processes of reverse osmosis and ion exchange. To do this, four types of water were characterized: drinking water (control), reverse osmosis waste water process used in the production of purified drinking water; waste water of both the ion exchange process and the reverse osmosis process, both from the Regional Hospital of Copiapo, Atacama, Chile. Subsequently, different samples of concrete containing the 4 types of water were manufactured and their resistance to compression at the ages of 7 and 28 days was evaluated. The results showed that in all cases, the concrete made with waste water, reached higher resistance to compression than the control sample. From this study, it can be concluded that the use of waste water in the manufacture of concrete, can b","PeriodicalId":391731,"journal":{"name":"Obras y proyectos","volume":"203 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115898659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of the static and seismic performance of a geogrid reinforced soil wall as bridge abutment in Concepción","authors":"M. González, F. Villalobos, A. Méndez, P. Carrillo","doi":"10.4067/S0718-28132018000200041","DOIUrl":"https://doi.org/10.4067/S0718-28132018000200041","url":null,"abstract":"espanolEl terremoto del 27 de febrero 2010 en Chile central y sur fue una prueba muy intensa para las soluciones con muro de suelo reforzado recientemente construidas como estribos de puente. Este terremoto de subduccion de magnitud momento 8.8 causo graves danos a varios muros de hormigon armado tradicionales para estribos de puentes. Sin embargo, no se registro mayor dano en soluciones relativamente nuevas y reforzadas con geosinteticos. Por esta razon, es importante revisar el diseno y construccion empleada en estos proyectos. Para este fin, se describe y estudia un caso representativo ubicado proximo al epicentro. Ademas, se entrega informacion sobre los suelos de fundacion, diseno y secuencia constructiva de los refuerzos de geosinteticos usados en los estribos de puente. Los suelos de fundacion eran desfavorables, correspondiendo principalmente a depositos fluviales y marinos proximos al cauce y desembocadura del rio Andalien. El analisis incluye la verificacion de la estabilidad estatica y sismica, tanto externa como interna. Tambien se realizan analisis de estabilidad global estatica y sismica. Los metodos usados en los analisis son equilibrio limite y pseudo estatico segun las recomendaciones de FHWA. Resultados muestran que el diseno fue adecuado para soportar un evento sismico tan fuerte en terminos de estabilidad interna y externa. No obstante, se encontro que la presencia de pilotes prevenia una falla sismica global del muro de suelo reforzado con geomallas como estribo de puente. Se realizan comentarios y observaciones finales relacionados con el diseno y construccion que podrian explicar la respuesta favorable de las estructuras reforzadas con geosinteticos sometidas a este fuerte terremoto de subduccion. EnglishThe 27th February 2010 earthquake in central and south of Chile was a very strong test for recently constructed geosynthetics reinforced soil wall solutions as bridge abutments. This 8.8 moment magnitude subduction earthquake caused severe damage to several traditional reinforced concrete walls for bridge abutments. However, no significant damage was found in relatively new geosynthetics reinforced solutions. For that reason, it is important to review the design and construction employed in these projects. To this end, a representative case located close to the epicentre is described and studied. Moreover, information is provided regarding the foundation soils, design and construction sequence of the geosynthetics reinforcement used for bridge abutments. The foundation soils were poor, corresponding mainly to marine and fluvial deposits close to the stream and mouth of the Andalien River. The analysis covers the verification of static and seismic external and internal stability. In addition, global static and seismic analyses are carried out. The methods used for the analyses are limit equilibrium and pseudo-static following recommendations of the FHWA. Results show that the design was adequate to cope with such a strong se","PeriodicalId":391731,"journal":{"name":"Obras y proyectos","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114945369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estudio de los pavimentos de túneles carreteros: ventajas de los pavimentos de hormigón frente a los bituminosos","authors":"J. Díaz, F. Hacar","doi":"10.4067/S0718-28132018000100087","DOIUrl":"https://doi.org/10.4067/S0718-28132018000100087","url":null,"abstract":"","PeriodicalId":391731,"journal":{"name":"Obras y proyectos","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131600655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Análisis dinámico de una torre autosoportada sujeta a cargas de viento y sismo","authors":"I. Fernández, Viviana Elena, Patricia Martín, Yanet Corona, I. A. Hernández","doi":"10.4067/S0718-28132018000100078","DOIUrl":"https://doi.org/10.4067/S0718-28132018000100078","url":null,"abstract":"","PeriodicalId":391731,"journal":{"name":"Obras y proyectos","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129889122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Análisis de un amortiguador de masa sintonizado óptimo en estructuras asimétricas no lineales","authors":"G. Espinoza, D. Neira, Alberto M. Cifuentes","doi":"10.4067/s0718-28132018000100039","DOIUrl":"https://doi.org/10.4067/s0718-28132018000100039","url":null,"abstract":"","PeriodicalId":391731,"journal":{"name":"Obras y proyectos","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117076393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluación de asentamientos en el tiempo de sistemas placa-pilote apoyados sobre depósitos arcillosos de Bogotá D.C. utilizando un modelo 3D de elementos finitos","authors":"Juan Sebastián Monzón, A. Várela","doi":"10.4067/S0718-28132018000100006","DOIUrl":"https://doi.org/10.4067/S0718-28132018000100006","url":null,"abstract":"","PeriodicalId":391731,"journal":{"name":"Obras y proyectos","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123205543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determinación del nivel de desempeño de un edificio habitacional estructurado en base a muros de hormigón armado y diseñado según normativa chilena","authors":"Ricardo Medina, Juan Music","doi":"10.4067/S0718-28132018000100063","DOIUrl":"https://doi.org/10.4067/S0718-28132018000100063","url":null,"abstract":"","PeriodicalId":391731,"journal":{"name":"Obras y proyectos","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116625481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}