Browsing by Author "Useche Infante, Danny"

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    Comportamiento de cimentaciones superficiales sobre arenas reforzadas con geosintéticos
    (2014) Useche Infante, Danny; Aiasaa Martínez, Gonzalo Martín; Arrúa, Pedro A.; Eberhardt, Marcelo G.
    Diversas investigaciones han reportado el efecto positivo de incluir geosintéticos en suelos granulares con el fin de mejorar el desempeño de fundaciones superficiales apoyadas en este tipo de suelos reforzados. Esta mejora se da gracias a la fuerza de tracción del material de refuerzo, la cual permite incrementar la capacidad portante y disminuir los asentamientos inmediatos del suelo de fundación. En el presente trabajo se realiza una implementación numérica de la metodología propuesta por Sharma, et. Al. (2009) para estudiar el comportamiento de dos tipos de arenas usadas con frecuencia en fundaciones de diferente tipo de estructuras en la ciudad de Córdoba Argentina. Inicialmente se realiza una revisión de los antecedentes experimentales y numéricos documentados en la literatura técnica referentes al comportamiento de suelos reforzados ante fundaciones superficiales, y posteriormente se estima la capacidad última de carga del suelo reforzado qu(R), así como la relación de capacidad de carga (BCR) utilizando parámetros conocidos de los suelos y materiales de reforzamiento empleados en el ámbito local.
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    Experimental study of behavior of circular footing on geogrid-reinforced sand
    (2019) Useche Infante, Danny; Aiassa Martínez, Gonzalo Martín; Arrúa, Pedro Ariel; Eberhardt, Marcelo Gabriel
    Load tests were carried out with a circular foundation of diameter, B = 100 mm, supported on geogrid-sand reinforced contained in a circular-steel tank with diameter of 600 mm and depth of 450 mm, to determine the increase produced in the bearing capacity by including geogrid layers in the sand. Two types of geogrid, uniaxial and biaxial, were used as reinforcement material. Besides, a parametric study was carried out to verify the effect of several factors on the behaviour of reinforced soil. The parameters considered in the study include the depth of the first geogrid layer, vertical separation between layers of geogrid, diameter of the geogrid, number of reinforcement layers, deep of the foundation, geogrid type, and relative density of the sand. Moreover, the effect of folding the edges of the geogrid layer was studied. Finally, regression models will be developed from the laboratory model test to perform an initial calculation of the bearing capacity of the reinforced sand. Results showed that the parameters studied have a significant influence on the performance of the footing in terms of bearing capacity. The proposed regression models presented an adequate approximation to the experimental results.
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    Model tests and numerical modeling on post-grouting effects of steel pipe micropiles
    (2024) Useche Infante, Danny; Aiassa Martínez, Gonzalo Martín; Arrúa, Pedro Ariel
    Steel pipe micropiles have been used successfully for deep foundations. To improve the performance of steel pipe micropiles, the post-grouting technology is employed worldwide due to its potential to increase the axial resistance and decrease the displacements in the micropile. This foundation is called grouted steel pipe micropile in the literature. The post grouting is commonly carried out at the micropile sides using grout delivery pipes. In this contribution, the results of scale model tests and numerical simulations with grouted steel pipe micropiles are presented. Model micropiles were tested within a calibration chamber containing silty soil prepared with a unit weight of 14 kN/m3. The stress level remained constant in the sample with the application of an overload (100 kPa) on the soil surface. Based on the results of numerical simulations, the scale effect on the axial resistance of pipe micropiles is considered. Furthermore, the influence of grout injection pressure on the pipe micropile behavior is studied. The analysis reveals that, for steel pipe micropiles in compression, due to increasing of grout injection pressure from 26.7 to 30.0 kPa, the ultimate axial resistance was improved by 19.0 and 33.7% compared to the micropile with an injection pressure of 25.0 kPa. Two main factors that improve the behavior of the micropile were identified, the first is the soil densification under the micropile tip originating from the micropile driving; and the second factor is the improvement of the micropile friction resistance due to the grout penetration into the surrounding soil caused by the grouting. Finally, a multiple regression equation to estimate the ultimate axial resistance of grouted steel pipe micropile is presented.
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    Performance evaluation of post-grouted drilled shafts: a review
    (2022) Useche Infante, Danny; Aiassa Martínez, Gonzalo Martín; Arrúa, Pedro Ariel
    Base grouting in drilled shafts has been used to improve the foundation performance. The main objectives of this technique are to generate a preload in the base soil, induce negative friction on the pile side, and improve the soil surrounding the shaft. In recent years, new experimental and numerical studies were published, which have helped to better understand the soil–post-grouted drilled shaft interaction mechanism. Likewise, new grouting devices were developed, and design methodologies were introduced. This review paper focuses on the analysis of available approaches to investigate the performance of post-grouted drilled shafts (PGDS). The mechanisms of post-grouting of drilled shafts to improve the bearing capacity of pile foundation are discussed, and some properties of the grout typically used in this procedure (such as water–cement ratio, type of grout, etc.) are described. Based on the literature survey, this study presents the devices used to distribute the grout at the tip and side pile, the grouting techniques, and the effect of grout pressure and grout volume on pile behavior. The investigation indicated that the enhancement in pile bearing capacity is affected by the grout quantity, grouting pressure, pile dimensions, soil type, etc. Subsequently, full-scale field tests, small-scale tests, and numerical investigations published to analyze the performance of PGDS are summarized. Finally, the design methodologies available in the technical literature and future developments for this type of foundation are discussed
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    Pilotes perforados con inyección de lechada cementicia en la punta: estado del arte.
    (2021) Useche Infante, Danny; Aiassa Martínez, Gonzalo Martín; Arrúa, Pedro Ariel; Eberhardt, Marcelo Gabriel
    En este artículo se presenta una revisión de antecedentes sobre pilotes perforados con inyección de lechada en la punta. Se analiza el efecto de la lechada en el comportamiento del pilote, así como los métodos constructivos y diferentes dispositivos para llevar a cabo esta técnica. Se eligieron seis estudios de caso reportados en la literatura técnica, los cuales cuentan con amplia información sobre el desempeño de este tipo de fundaciones. Los estudios consultados mostraron que, al realizar la inyección de carga en la punta del pilote, se incrementa significativamente la capacidad de carga por punta y por fricción de la fundación. Además, la lechada aumenta la rigidez del suelo y disminuye los asentamientos en el pilote, siendo una solución muy apropiada para fundaciones profundas.
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    Pilotes perforados con inyección de lechada cementicia en la punta: estudio de casos.
    (2022) Useche Infante, Danny; Aiassa Martínez, Gonzalo Martín; Arrúa, Pedro Ariel; Eberhardt, Marcelo Gabriel
    En este artículo se presenta una revisión de antecedentes sobre pilotes perforados con inyección de lechada en la punta. Se analiza el efecto de la lechada en el comportamiento del pilote, así como los métodos constructivos y diferentes dispositivos para llevar a cabo esta técnica. Se eligieron seis estudios de caso reportados en la literatura técnica, los cuales cuentan con amplia información sobre el desempeño de este tipo de fundaciones. Los estudios consultados mostraron que, al realizar la inyección de carga en la punta del pilote, se incrementa significativamente la capacidad de carga por punta y por fricción de la fundación. Además, la lechada aumenta la rigidez del suelo y disminuye los asentamientos en el pilote, siendo una solución muy apropiada para fundaciones profundas.
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    Scale effect on the behavior of circular footing on geogrid-reinforced sand using numerical analysis
    (2021) Useche Infante, Danny; Aiassa Martínez, Gonzalo Martín; Arrúa, Pedro Ariel; Eberhardt, Marcelo Gabriel
    Using plate load test to evaluate the scale effects of shallow foundation bearing capacity on geogrid-reinforced sand is expensive because large boxes need to be built, and the devices to apply the loads to the reinforced soil are complex. Consequently, the finite element method is an alternative to investigate this phenomenon. In this study, a series of 3D axi-symmetry finite element models were developed to study the scale effect on the bearing capacity of circular footings resting on geogrid-reinforced sand. First, a 100 mm-diameter circular foundation supported by geogrid-reinforced sand was simulated in order to validate the finite element model with laboratory tests. Subsequently, different models were made by increasing the diameter of the foundation and the diameter of the geogrid in the same proportion. Modelling results indicated that as the foundation diameter increased, the bearing capacity of unreinforced and reinforced soil decreased. Likewise, the benefit obtained from the reinforcement was less when the model size was increased
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    Scale model to measure stress under circular footings resting on sand
    (2018) Useche Infante, Danny; Aiassa Martínez, Gonzalo Martín; Arrúa, Pedro Ariel; Eberhardt, Marcelo Gabriel
    This paper presents the results of a series of load tests carried out with a foundation model supported by sand. The aim of this study is to measure the stresses in the soil that occur when applying loads with a circular foundation model. Sand was placed in a circular tank of 60 cm in diameter and 45 cm in height. Diaphragm load cells were used to measure the stresses. It was used to determine the effect of the relative density in the vertical distribution of stresses in the sand. The stresses measured with the load cells were compared with those estimated with the Boussinesq’s method and were validated using a finite element model. The results showed that the inclusion of cells in the soil produced an alteration in the stress–settlement behaviour of circular footing resting on sand. Boussinesq’s method presented an acceptable approximation to the stresses measured with the load cells.
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    Shear strength behavior of different geosynthetics, graded sand, silty sand
    (2016) Useche Infante, Danny; Arrúa, Pedro A.; Aiassa Martínez, Gonzalo Martín
    This paper presents the results of a series of load tests carried out with a foundation model supported by sand. The aim of this study is to measure the stresses in the soil that occur when applying loads with a circular foundation model. Sand was placed in a circular tank of 60 cm in diameter and 45 cm in height. Diaphragm load cells were used to measure the stresses. It was used to determine the effect of the relative density in the vertical distribution of stresses in the sand. The stresses measured with the load cells were compared with those estimated with the Boussinesq’s method and were validated using a finite element model. The results showed that the inclusion of cells in the soil produced an alteration in the stress–settlement behaviour of circular footing resting on sand. Boussinesq’s method presented an acceptable approximation to the stresses measured with the load cells.