Piles subjected to torsional cyclic load: Numerical analysis

© 2019 Nimbalkar, Punetha, Basack and Mirzababaei. Pile foundations supporting large structures (such as high-rise buildings, oil drilling platforms, bridges etc). are often subjected to eccentric lateral load (in addition to the vertical loads) due to the action of wind, waves, high speed traffic, and ship impacts etc. The eccentric lateral load, which is usually cyclic (repetitive) in nature, induces torsion in the pile foundation. This paper presents a numerical model based on boundary element approach to study the performance of a single pile subjected to the torsional cyclic load. The model is initially validated by comparing it with the experimental data available from the literature. Thereafter, the model has been utilized to conduct a parametric study to understand the influence of the torsional cyclic loading parameters on the axial pile capacity. The results indicated that the model is able to capture the degradation in the axial pile capacity due to the torsional cyclic loading with a reasonable accuracy. Moreover, the parametric study showed that the frequency, amplitude and number of cycles play a significant role in the torsional cyclic response of the pile. The present study is essential for the development of design guidelines for pile foundations subjected to torsional cyclic load

Performance of laterally loaded piles considering soil and interface parameters

© 2014 Techno-Press, Ltd. To investigate the soil-pile interactive performance under lateral loads, a set of laboratory model tests was conducted on remoulded test bed of soft clay and medium dense sand. Then, a simplified boundary element analysis had been carried out assuming floating pile. In case of soft clay, it has been observed that lateral loads on piles can initiate the formation of a gap, soil heave and the tension crack in the vicinity of the soil surface and the interface, whereas in medium dense sand, a semi-elliptical depression zone can develop. Comparison of test and boundary element results indicates the accuracy of the solution developed. However, in the boundary element analysis, the possible shear stresses likely to be developed at the interface are ignored in order to simplify the existing complex equations. Moreover, it is unable to capture the influence of base restraint in case of a socketed pile. To bridge up this gap and to study the influence of the initial stress state and interface parameters, a field based case-study of laterally-loaded pile in layered soil with socketed tip is explored and modelled using the finite element method. The results of the model have been verified against known field measurements from a case-study. Parametric studies have been conducted to investigate the influence of the coefficient of lateral earth pressure and the interface strength reduction factor on the results of the model

A boundary element analysis on the influence of Krc and e/d on the performance of cyclically loaded single pile in clay

The environment prevalent in oceans necessitates the piles supporting offshore structures to be designed against lateral cyclic loading initiated by wave action. Such quasi-static load reversal induces deterioration in the strength and stiffness of the soil-pile system, introducing progressive reduction in the bearing capacity associated with increased settlement of the pile foundation. To understand the effect of lateral cyclic load on axial response of single piles in soft clay, a numerical model was previously developed and validated by the author. Using the methodology, further analysis has been carried out to investigate how the variation in relative pilesoil stiffness and eccentricity effects the degradation of axial pile capacity due to the effect of lateral cyclic load. This paper presents a brief description of the methodology, analysis and interpretations of the theoretical results obtained from the further analysis and the relevant conclusions drawn there from

Analytical and numerical solutions to selected research problems in geomechanics and geohydraulics

-Geomechanical and geohydraulic engineering is a promising study area with several emerging research concerns. Most of such problems requires advanced level of mathematics to arrive at specific solutions. A wide range of approaches includes several analytical and numerical techniques for better understanding of such problems. In this paper, a few selected research problems are identified, and their solution techniques are demonstrated. The specific areas relevant to such problems are soil-structure interaction, ground improvement and groundwater hydraulics. This paper presents the problem identification, their mathematical solutions and results as well as pertinent analyses and useful interpretations to practice

Enfermedad de Gaucher en Argentina: un informe del Registro Internacional de Gaucher y del Grupo Argentino de Diagnóstico y Tratamiento de la Enfermedad de Gaucher

La Enfermedad de Gaucher por su baja frecuencia está incluida dentro de las enfermedades huérfanas. En 1991 comenzó el ingreso de pacientes en el Registro Internacional de Gaucher. En 1992 se incorporaron los primeros dos pacientes de Latinoamérica. En 2006 se creó el Grupo Argentino de Diagnóstico y Tratamiento de la Enfermedad de Gaucher siendo sus objetivos principales el entendimiento de la prevalencia, presentación, manejo y tratamiento de la Enfermedad de Gaucher en Argentina. Hasta el 1 de febrero del 2013 ingresaron al Registro Internacional 5.986 pacientes provenientes de 60 países, de los cuales 133 (2.22%) fueron argentinos. El análisis de esta publicación fue realizado sobre 133 pacientes con Enfermedad de Gaucher. Esta es la primera publicación del Grupo Argentino de Diagnóstico y Tratamiento en base a los datos del Registro Internacional. La casuística argentina mostró un predominio femenino y la forma clínica más frecuente fue el tipo 1 (97.7%, n=128). El genotipo fue identificado en 57 pacientes (42.9%), siendo el más frecuente el N370S/ otro alelo (82.5%). Entre los pacientes con datos reportados, los síntomas basales predominantes, previos al inicio del tratamiento con Imiglucerasa que predominaron fueron la esplenomegalia (100%, n=13) y la hepatomegalia (88.9%, n=8) y como citopenias más frecuentes, la trombocitopenia (64.2%, n=34) y la anemia (45.9%, n=28). La infiltración de la médula ósea como un marcador específico de enfermedad ósea se encontró en el 50% de los pacientes. En total, el 85.7% de los pacientes argentinos reciben terapia de reemplazo enzimático con Imiglucerasa, lográndose las metas terapéuticas, en la mayoría de los casos, en la última evaluación. Las metas terapéuticas más frecuentemente alcanzadas resultaron: el control de las manifestaciones óseas (dolor óseo y crisis ósea, 81.9% y 99% respectivamente) y la normalización de la hemoglobina (86.5%). La terapia de reemplazo enzimática con Imiglucerasa, a largo plazo en la población argentina demostró ser una herramienta eficaz para mejorar los parámetros clínicos y bioquímicos de la Enfermedad de Gaucher tipo1.Fil: Drelichman, G.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Fernández Escobar, Nicolás. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Basack, Nora. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños "Ricardo Gutiérrez"; ArgentinaFil: Kohan, R.. Registro Argentino de Gaucher; ArgentinaFil: Watman, N.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Bolesina, M.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Agudos "Ramos Mejía"; ArgentinaFil: Elena, G.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Veber, S. E.. Gobierno de la Ciudad de Buenos Aires. Hospital General de Niños Pedro Elizalde (ex Casa Cuna); ArgentinaFil: Dragosky, M.. Gobierno de la Ciudad de Buenos Aires. Hospital de Oncología Marie Curie; ArgentinaFil: Annetta, I.. Gobierno de la Ciudad de Buenos Aires. Hospital de Oncología Marie Curie; ArgentinaFil: Feliu, A.. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Sciuccati, Gabriela. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Cuello, María Fernanda. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de la Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fynn, Alcira. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de la Plata; ArgentinaFil: Dodelson de Kremer, Raquel. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de la Plata; ArgentinaFil: Angaroni, Celia Juana. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de la Plata; ArgentinaFil: Giner Ayala, Alicia. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de la Plata; ArgentinaFil: Del Valle Oller, Ana María. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de la Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Guelbert, Norberto Bernardo. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de la Plata; ArgentinaFil: Delgado, María Andrea. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de la Plata; ArgentinaFil: Becerra, Adriana Berónica. Provincia de Buenos Aires. Ministerio de Salud. Hospital de Niños "Sor María Ludovica" de la Plata; ArgentinaFil: Oliveri, María Beatriz. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Larroudé, M.. Centro Médico TIEMPO; ArgentinaFil: Masllorens, F.. Provincia de Buenos Aires. Ministerio de Salud. Hospital Nacional “Prof. Dr. A. Posadas"; ArgentinaFil: Szlago, M.. Fundación para el eEstudio de las Enfermedades Neurometabólicas; Argentina. Laboratorio de Neuroquímica “Dr. N. A. Chamoles”; ArgentinaFil: Schenone, A.. Laboratorio de Neuroquímica “Dr. N. A. Chamoles”; Argentina. Fundación para el eEstudio de las Enfermedades Neurometabólicas; Argentin

Response of vertical pile group subjected to horizontal cyclic load in soft clay

The environment prevalent in ocean necessitates the piles supporting offshore structures to be designed against lateral cyclic loading initiated by wave action. Such quasi-static load reversal induces deterioration in the strength and stiffness of the soil-pile system introducing progressive reduction in the bearing capacity as well as the pile head displacement. To understand the effect of lateral cyclic load on lateral capacity of pile group in soft clay, a series of laboratory experiments were performed on model piles in soft cohesive soil. This paper presents the experimental observations made and the relevant conclusions drawn there from

A boundary element analysis on the influence of Krc and e/d on the performance of cyclically loaded single pile in clay

The environment prevalent in oceans necessitates the piles supporting offshore structures to be designed against lateral cyclic loading initiated by wave action. Such quasi-static load reversal induces deterioration in the strength and stiffness of the soil-pile system, introducing progressive reduction in the bearing capacity associated with increased settlement of the pile foundation. To understand the effect of lateral cyclic load on axial response of single piles in soft clay, a numerical model was previously developed and validated by the author. Using the methodology, further analysis has been carried out to investigate how the variation in relative pilesoil stiffness and eccentricity effects the degradation of axial pile capacity due to the effect of lateral cyclic load. This paper presents a brief description of the methodology, analysis and interpretations of the theoretical results obtained from the further analysis and the relevant conclusions drawn there from

A boundary element analysis on the influence of Krc and e/d on the performance of cyclically loaded single pile in clay

The environment prevalent in oceans necessitates the piles supporting offshore structures to be designed against lateral cyclic loading initiated by wave action. Such quasi-static load reversal induces deterioration in the strength and stiffness of the soil-pile system, introducing progressive reduction in the bearing capacity associated with increased settlement of the pile foundation. To understand the effect of lateral cyclic load on axial response of single piles in soft clay, a numerical model was previously developed and validated by the author. Using the methodology, further analysis has been carried out to investigate how the variation in relative pilesoil stiffness and eccentricity effects the degradation of axial pile capacity due to the effect of lateral cyclic load. This paper presents a brief description of the methodology, analysis and interpretations of the theoretical results obtained from the further analysis and the relevant conclusions drawn there from

Free strain analysis of the performance of vertical drains for soft soil improvement

© 2017 Techno-Press, Ltd. Improvement of soft clay deposit by preloading with vertical drains is one of the most popular techniques followed worldwide. These drains accelerate the rate of consolidation by shortening the drainage path. Although the analytical and numerical solutions available are mostly based on equal strain hypothesis, the adoption of free strain analysis is more realistic because of the flexible nature of the imposed surcharge loading, especially for the embankment loading used for transport infrastructure. In this paper, a numerical model has been developed based on free strain hypothesis for understanding the behaviour of soft ground improvement by vertical drain with preloading. The unit cell analogy is used and the effect of smear has been incorporated. The model has been validated by comparing with available field test results and thereafter, a hypothetical case study is done using the available field data for soft clay deposit existing in the eastern part of Australia and important conclusions are drawn therefrom