Academic literature on the topic 'Raft and pile foundation'
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Journal articles on the topic "Raft and pile foundation"
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Sharma, V. J., S. A. Vasanvala, and C. H. Solanki. "Behaviour of Load-Bearing Components of a Cushioned Composite Piled Raft Foundation Under Axial Loading." Slovak Journal of Civil Engineering 22, no. 4 (2014): 25–34. http://dx.doi.org/10.2478/sjce-2014-0020.
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Abstract In the last decade piled raft foundations have been widely used around the world as intermediate foundation systems between piles and rafts to control the settlement of foundations. However, when those piles are structurally connected to rafts, relatively high axial stresses develop in relatively small numbers of piles, which are often designed to fully mobilize their geotechnical capacities. To avoid a concentration of stress at the head of piles in a traditional piled raft foundation, the raft is disconnected from the piles, and a cushion is introduced between them. Also, to tackle an unfavourable soil profile for a piled raft foundation, the conventional piled raft has been modified into a cushioned composite piled raft foundation, where piles of different materials are used. In the current study the behavior of cushioned foundation components, which transfer the load from the structure to the subsoil, are analyzed in detail, i.e., the thickness of the raft, the length of a long pile and the modulus of a flexible pile.
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Gunawan, H., L. Flessati, and P. Marveggio. "Optimizing foundation performance: the impact of raft on piled raft foundation in sand." Géotechnique Letters 15, no. 2 (2025): 1–5. https://doi.org/10.1680/jgele.24.00136.
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Conventional piled foundation designs tend to be overly conservative since the beneficial role of the raft is often neglected by assuming the piles to be the only part of the structure interacting with the soil. The contribution of the raft to the global response of the foundation is particularly important in the case of “large” piled rafts, where the pile length is comparable to the raft width. This configuration, although not theoretically optimal, is common for existing foundations of bridges and high-rise buildings. Although the beneficial effect of raft–pile–soil interaction on both bearing capacity and stiffness is generally acknowledged, simple and reliable approaches recognized by design codes are not yet available. Aiming at providing simple tools for designing large piled rafts under static and dynamic/cyclic loads, in this paper a numerical study is presented, with preliminary finite element analyses performed to examine the mechanical behaviour of a “large” piled raft under vertical centred loads and positioned on a dry sand layer. This paper presents the findings of this study, comparing the performance of the piled raft to the corresponding pile group and unpiled raft, and highlights the importance of considering the presence of rafts in the design of piled foundations.
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Dhage, Amit, and S. S. Solanke. "Comparative Analysis of Raft, Pile & Piled Raft Foundation using Designing Software." IOP Conference Series: Earth and Environmental Science 1193, no. 1 (2023): 012006. http://dx.doi.org/10.1088/1755-1315/1193/1/012006.
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Abstract Raft foundations are essentially a slab that extends the entire length of the building, sustaining and dispersing its mass to the earth. A pile foundation is a collection of columns that are erected or inserted into the ground to distribute weight to the subsoil underneath. A pile is a long, cylindrical construction made made of a sturdy substance such as concrete. Building loads are transferred to hard strata, rocks, or high-bearing-capacity soil using piles. Pinned raft foundations are a combination of a pile and a raft slab. They’re frequently used for large structures and when the soil is insufficient to avoid excessive settling. As a result of this, the soil is less strained. Pile foundations are necessary in areas where buildings are large and heavy, yet the soil beneath them is weak. In areas where settlement. Deep foundations with pile rafts can help move strata Adding piles to a raft increases the effective size of the foundation and can help it sustain horizontal loads. On a G+20 residential structure, the research of raft, pile, and stacked raft foundations was conducted using structural software safe 16. For a zone factor II earthquake, a building’s seismic study is completed. The pile raft foundation has less upward soil carrying load and less settling than the raft foundation, according to a study of the G+20 structure for pile, raft, and piled raft foundations.
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Rahman, Arief, Ferry Fatnanta, and Syawal Satibi. "Analysis of the capability of pile assembly foundations in soft soil in physical modeling of variationsiin laboratory scale distances." astonjadro 12, no. 1 (2023): 136. http://dx.doi.org/10.32832/astonjadro.v12i1.8139.
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<p>The capacity of raft foundations, pile foundations and pile rafts on soft soil with variations in the distance between the piles. Perform analysis of the carrying capacity and settlement of each foundation test and then compare the results of the theoretical carrying capacity research with the analysis of carrying capacity calculations. The implementation of the test prepares the test along with samples of the raft foundation, pile foundation and pile raft foundation. The test were carried out using a gradual load then a dial gauge is placed at both ends of the sample raft and the load reading is taken. The pile foundation was tested with a decrease of 10 cm while the settlement on the raft foundation and the pile raft foundation was 3 cm, the carrying capacity of the raft foundation was 24 kg, the pile foundation varied 4D distances; 6D and 8D, namely 7.5 kg and the foundation of the pile raft with variations in 4D distance; 6D and 8D are 26 ; 32 and 32 kg. In the interpretation method, the pile raft foundation with various distances increased from 4D to 6D but decreased in 8D. Pile raft foundations with various distances between pile have not a significant effect where raft foundations are more dominant in supporting resistance than pile foundations.</p>
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Al-Mosawi, Mosa J., Mohammed Y. Fattah, and Abbas A. O. Al-Zayadi. "EXPERIMENTAL OBSERVATIONS ON THE BEHAVIOR OF A PILED RAFT FOUNDATION." Journal of Engineering 17, no. 04 (2011): 807–28. http://dx.doi.org/10.31026/j.eng.2011.04.13.
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The piled raft is a geotechnical composite construction consisting of three elements: piles, raft and soil.In the design of piled rafts, the load shared between the piles and the raft, and the piles are used up to aload level that can be of the same order of magnitude as the bearing capacity of a comparable singlepile or even greater. Therefore, the piled raft foundation allows reduction of settlements in a veryeconomic way as compared to traditional foundation concepts.This paper presents experimental study to investigate the behavior of piled raft system in sandysoil. A small scale “prototype” model was tested in a sand box with load applied to the system througha compression machine. The settlement was measured at the center of the raft, strain gages were usedto measure the strains and calculate the total load carried by piles. Four configurations of piles (2x1,3x1, 2x2 and 3x2) were tested in the laboratory, in addition to rafts with different sizes. The effects ofpile length, pile diameter, and raft thickness on the load carrying capacity of the piled raft system areincluded in the load-settlement presentation.It was found that the percentage of the load carried by piles to the total applied load of thegroups (2x1, 3x1, 2x2, 3x2) with raft thickness of 5 mm, pile diameter of 9 mm, and pile length of 200mm was 28% , 38% , 56% , 79% , respectively. The percent of the load carried by piles increases withthe increase of number of piles.
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Melese, Fekadu. "Improved Performance of Raft Foundation Using Detached Pile Columns in Loose Subsoil Conditions." Advances in Civil Engineering 2022 (March 8, 2022): 1–18. http://dx.doi.org/10.1155/2022/4002545.
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Piles act as settlement reducers in case of connected piled-raft foundation and hence decrease the settlements of the raft. The design concept of the connected piled-raft foundations is to lessen the number of piles and utilize the bearing capacity of the system piled raft. Due to significant straining actions at the pile head-raft connection, an alternative technique is proposed to disconnect the piles from the raft. A granular layer (cushion) beneath the raft is incorporated. The disconnection has a beneficial effect on reducing axial load compared to connected piles. For small piled rafts, nonconnected piled rafts show less stiffness than connected piled rafts, and the soil is highly stressed and shows greater raft settlement. In the case of the large piled raft, nonconnected piled rafts show greater settlement efficiency. Cushion stiffness was realized to be more substantial for a nonconnected piled raft with shorter piles than one with longer piles. The results show that the load transfer mechanism in a nonconnected piled raft is mainly governed by the thickness and stiffness of the cushion layer and by the stiffness of the subsoil.
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Kannaujiya, Pratish, and Vijay Kumar Srivastava. "Behavior of Different Configuration of Piled Raft Foundation for a High-Rise Building by using FEM." IOP Conference Series: Materials Science and Engineering 1236, no. 1 (2022): 012006. http://dx.doi.org/10.1088/1757-899x/1236/1/012006.
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Abstract In this paper, the numerical simulation is performed on two piled raft configurations having uniform loading on a piled raft foundation. To investigate the interaction between various parameters of pile soil foundation with varying components of its length of pile, diameter and raft thickness. These components are critical for increasing the foundation’s bearing capacity. It’s important aspect to achieve a reliable design to optimize piled raft foundations subjected to uniformed load- settlement behaviors of the curves. These load – settlements are basically depending on the changing of their components piled raft foundation. These component of piled raft foundations to choose an optimal selection of embedded length of pile (L/dP), normalized diameter of pile (L/dP) and normalized raft thickness (tR/dP). The effect of load-settlement on distributions of shear force and bending moments is also investigated. In this study, a finite elements methods based on numerical tools ELPLA software is used for numerical simulation. The study’s findings validate the numerical analysis for the calculation of proper pile configuration arrangement, as a result of settlements. It will be generated as formation of contours patterns as shear stress and bending moments on the rafts, may be minimized with the total pile length. The conclusion drawn from the study validates the numerical analysis for the computation of proper pile arrangement can results in total and differential settlements, as well as generated shear stress and bending moments on the rafts, are all being reduced, with identical total pile length. Moreover, it captures the contours patterns of different behaviors of piled raft settlements, maximum shear force and maximum moments.
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Alhassani, Athraa Mohammed Jawad, and Ala Nasir Aljorany. "Parametric Study on Unconnected Piled Raft Foundation Using Numerical Modelling." Journal of Engineering 26, no. 5 (2020): 156–71. http://dx.doi.org/10.31026/j.eng.2020.05.11.
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Piled raft is commonly used as foundation for high rise buildings. The design concept of piled raft foundation is to minimize the number of piles, and to utilize the entire bearing capacity. High axial stresses are therefore, concentrated at the region of connection between the piles and raft. Recently, an alternative technique is proposed to disconnect the piles from the raft in a so called unconnected piled raft (UCPR) foundation, in which a compacted soil layer (cushion) beneath the raft, is usually introduced. The piles of the new system are considered as reinforcement members for the subsoil rather than as structural members. In the current study, the behavior of unconnected piled rafts systems has been studied numerically by means of 3D Finite Element analysis via ABAQUS software. The numerical analysis was carried out to investigate the effect of thickness and stiffness of the cushion, pile length, stiffness of foundation soil, and stiffness of bearing soil on the performance of the unconnected piled raft. The results indicate that when unconnected piles are used, the axial stress along the pile is significantly reduced e.g. the axial stress at head of unconnected pile is decreased by 37.8% compared with that related to connected pile. It is also found that the stiffness and thickness of the cushion, and stiffness of foundation soil have considerable role on reduction the settlement.
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Chore, Hemant, Junaid Siddiqui, and Ashish Kishore. "Parametric Investigations into the Analysis of Piled Raft for Multi-Storeyed Building." Journal of Civil Engineering Frontiers 3, no. 02 (2023): 67–73. http://dx.doi.org/10.38094/jocef30260.
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This paper presents the analysis of the piled raft for a 50-story building using an approximate method to estimate the settlement and load distribution of the foundation. The pile and soils are considered to be interacting springs, and the raft is represented as a thin plate. The model takes into account both the resistance of the piles and the resistance of the raft foundation. It is calculated how the raft, soil, and pile interact. The suggested technique enables the use of the finite element based program ETABS to quickly address the issues of small, non-uniformly arranged rafts and big, non-uniformly ordered rafts. The effect of different pile length and diameter is evaluated on the behaviour of piled raft. With an increase in pile lengths, the moments in the raft are found to increase while the settlement of the pile decreases. Further, increases in pile diameter are found to increase the moments in the raft while decreasing the settlement of the raft. The parameters such as pile diameter and pile length have a considerable effect on the response of a foundation considered in the present study
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Bralović, Nemanja, Iva Despotović, and Danijel Kukaras. "Experimental Analysis of the Behaviour of Piled Raft Foundations in Loose Sand." Applied Sciences 13, no. 1 (2022): 546. http://dx.doi.org/10.3390/app13010546.
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This paper presents the experimental analysis that was conducted on small-scale 1g physical models of piled raft foundation structures with a group of 2 × 2 piles in loose sand. The purpose of the piles was to reduce the settlement of the raft. The test program included twelve experiments, three of which were conducted on a raft alone and nine on piled rafts at pile distances of 3d, 4d, and 5d and pile lengths of 10d, 20d, and 40d, where d is pile diameter. The test results show that the current conventional approach to design of piled raft foundations, at a high safety load factor in piles that assume to take the whole external applied load, is very conservative. Instead, it is more economical to apply a low bearing capacity factor for piles as settlement reducers and maximize use of raft bearing capacity to carry part of the external load.
Dissertations / Theses on the topic "Raft and pile foundation"
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Ayfan, Emad. "Design method for axially loaded piled raft foundation with fully mobilised friction piles." Doctoral thesis, Universite Libre de Bruxelles, 2012. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209604.
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In the present work, a settlement-based method is proposed to design piled raft foundation. The proposed design method is found to be very efficient, economical and requires less calculation time. Simple software can be used to execute all the interactions and loop calculations.<p>Unlike methods with numerical techniques, there are practically no limitations for the number of individual piles under the raft, size of the group and the group shape or layout. It can also be applied to piles with different length or piles that are located within multi-layered soils.<p>The raft is designed first according to the allowable settlement that is pre-defined by the structural requirements and with the necessary factor of safety. When raft suffers excessive settlement, then the load that causes excess raft settlement beyond the required limit is to be transferred to the fully mobilised frictional piles. <p>The fully mobilised shaft (with no end bearing) piles are designed with factor of safety close to unity since their function is only to reduce raft settlement and since the raft has an adequate bearing capacity.<p>Geometry of these piles is chosen to fully mobilise their shafts capacity with low settlement level in order to comply with load/settlement requirement and reduce raft settlement to the pre-defined level. <p><br>Doctorat en Sciences de l'ingénieur<br>info:eu-repo/semantics/nonPublished
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Fatemi-Ardakani, B. "A contribution to the analysis of pile-supported raft foundation." Thesis, University of Southampton, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379319.
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Yilmaz, Beren. "An Anlaytical And Experimental Study On Piled Raft Foundations." Master's thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611500/index.pdf.
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Two different concepts and design procedures namely settlement reducing piles and piled raft foundations have been studied independently in this thesis.
A laboratory study is conducted on model rafts with differing number of model settlement reducing piles. Pile length, pile diameter, type of soil and size of raft are kept constant and settlements are measured under sustained loading. Remolded
kaolin is consolidated under controlled stresses before tests are performed in model boxes. The tests are conducted under two sustained loadings of 75 kPa and 40 kPa. 0(raft), 16 and 49 number of piles are used. During the tests, all of the skin friction is mobilized. Several tests are conducted for each combination to see the variability. It is concluded that increasing the pile number beyond an optimum value is inefficient as far as the amount of settlement is considered. Also an analytical procedure has been followed to calculate settlements with increasing number of piles. In the second part of this thesis, finite element analyse have been performed on a piled raft foundation model, using Plaxis 3D Foundation Engineering software. This analyse are supported with analytical methods. The piled raft model is loaded with
450 kPa raft pressure. The studies are conducted in two sets in which different pile lengths are used<br>25 m and 30 m respectively. The numbers of piles are increased from 63 to 143. All other parameters are kept constant. The results showed that again an optimum number of piles will be sufficient to reduce the settlement to the acceptable level. The analytical methods indicate a similar behavior. The comparison and results are presented in the study.
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Bohn, Cécilia. "Serviceability and safety in the design of rigid inclusions and combined pile-raft foundations." Thesis, Paris Est, 2015. http://www.theses.fr/2015PEST1096/document.
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Les inclusions rigides sont un concept récent développé dans le prolongement des fondations mixtes, avec un matelas de transfert de charges entre les colonnes et la structure. Des méthodes de calculs et des concepts de sécurité existent pour ces systèmes combinés, notamment en France où le module pressiométrique mesuré et les recommandations ASIRI (IREX 2012) pour les inclusions rigides sont utilisés. Le dimensionnement classique des pieux basé sur une simple vérification de la portance des colonnes isolées ne peut pas être appliqué à ces systèmes combinés. Les tassements peuvent être plus importants du fait de la part significative de charge reprise par le sol. Le présent travail est une contribution au développement des méthodes de calcul et de dimensionnement en déplacement (préconisé par l'Eurocode 7, EN 1997-1 2004) pour les systèmes combinés sous charge verticale, en particulier au niveau international où des mesures in situ de module de sol ne sont généralement pas disponibles. Les éventuelles particularités de ces systèmes, notamment la sensibilité de colonnes non renforcées de petit diamètre, devaient également être examinées. La méthode de transfert de charge (“load transfer method”, LTM) est identifiée comme un outil d'ingénieur particulièrement adapté au calcul des systèmes combinés présentant une géométrie relativement simple. L'interaction sol-colonne en frottement et en pointe est définie par des courbes de transfert de charge (ou courbes “t-z” et “q-z”). Les méthodes en milieu continu comme la méthode des éléments finis sont à réserver en général aux cas complexes. Le comportement non-linéaire des semelles est examiné sur la base de mesures obtenues dans la littérature. Cette étude aboutit à la proposition d'une courbe charge-tassement hyperbolique pour les semelles. Cette courbe de mobilisation est définie de sorte qu'il y ait concordance avec la méthode linéaire habituelle pour un tiers de la charge ultime de la semelle. Le comportement de pieux isolés est étudié avec de nombreux essais de chargement instrumentés et non-instrumentés pour différents types de pieux et de sol. Une alternative aux courbes de transfert de charge selon Frank et Zhao (1982), basées sur le module pressiométrique, est recherchée. Des courbes de transfert de charge de type racine cubique et hyperbolique sont proposées pour tous types de pieux et de sol. La raideur des courbes proposées dépend d'une bonne estimation des valeurs ultimes de frottement et de résistance de pointe. Au contraire, la raideur initiale des courbes de Frank et Zhao est entièrement définie par le module pressiométrique, ce qui permet d'éviter des erreurs en termes de raideur. Les courbes de mobilisation proposées pour les fondations superficielles et pour les pieux sont combinées et étendues au cas des systèmes combinés. Cette méthode est implémentée comme option LTM dans le programme KID (Keller company 2015). Les prévisions avec le modèle proposé sont en très bonne adéquation avec les mesures effectuées sur 3 sites documentés dans la littérature. Une étude paramétrique montre une transition continue entre la fondation mixte et les inclusions rigides et une possibilité d'optimisation avec une diminution significative des efforts dans les colonnes et dans la fondation superficielle si un matelas est utilisé. En complément, une comparaison avec des calculs en éléments finis en 3D dans un cas théorique de semelle sur colonnes confirme que la méthode de transfert de charge développée est très performante pour des géométries simples. Une analyse de sensibilité est effectuée avec des modèles éléments finis axisymmétriques et 3D avec Plaxis (2013, 2014). Les imperfections géométriques ont principalement une incidence sur l'intégrité structurelle des colonnes non-armées de faible diamètre. Cependant, ces effets sont atténués dans les systèmes combinés en comparaison avec la colonne isolée du fait des possibilités de redistribution des charges dans le système<br>Rigid inclusions represent a further development of combined pile-raft foundations, comprising a load transfer platform between the columns and the structure. Calculation methods and design concepts are available for such combined systems in particular in France, based on measured pressuremeter modulus values and on the French recommendations ASIRI for rigid inclusions (IREX 2012). The conventional pile design consisting only of a bearing capacity check for the individual column cannot be applied to such combined systems. The expected settlements may be larger due to a significant load proportion supported by the soil. The present work contributes to the development of displacement-based calculation methods (advocated by the Eurocode 7, EN 1997-1 2004) and design methods for combined systems under vertical loads, in particular on an international level where in general no in situ soil modulus values are measured. Possible particularities of such systems, like the sensitivity of unreinforced small-diameter columns, also had to be investigated. The load transfer method (LTM) is identified as a straightforward engineering tool for the calculation of combined systems with relatively simple geometries. The soil-column interaction in terms of skin friction and tip resistance is described by deformation-dependent load transfer curves (or “t-z” and “q-z” curves). Continuum methods like the finite element method should be preferred only for complex cases in general. The non-linear load-settlement behaviour of single footings up to failure is analysed based on measurements given in the literature. This yields the proposal of a hyperbolic load-settlement curve for footings. This mobilization curve is defined in a way to match the linear usual method for one third of the footing ultimate load. The behaviour of single piles is investigated based on numerous available instrumented and non-instrumented pile load tests with different pile and soil types. A reliable alternative to the load transfer curves after Frank and Zhao (1982), which are based on the pressuremeter modulus, is sought. Cubic root and hyperbolic axial load transfer curves are proposed for all pile and ground types. The stiffness accuracy of the proposed curves depends on an accurate estimation of the ultimate skin friction and tip resistance values. On the contrary, the initial stiffness of the Frank and Zhao curves is fully described by the pressuremeter modulus, avoiding thus errors in the stiffness. The proposed mobilization curves for the shallow and pile foundation behaviours are combined and extended for all combined systems. The proposed method is implemented as the LTM option into the software KID (Keller company 2015). The prediction with the developed model matches very well the measurements made for 3 different cases from the literature. A parametric study shows a smooth transition between the combined pile-raft foundation case and the rigid inclusion case and a potential for optimisation with a significant reduction of the internal forces in the columns and in the rigid slab when a load transfer platform is used. In addition, a comparison with 3D finite element calculations for a theoretical footing case with columns confirms that the developed load transfer method is very reliable for simple geometries. Sensitivity investigations using the axisymmetric and 3D finite element method with Plaxis (2013, 2014) are performed. Geometrical imperfections impact mainly the structural integrity of small-diameter unreinforced columns. However, these effects are reduced in combined systems compared to the single column case due to the possibility of redistribution of the loads within the system
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Stacul, Stefano [Verfasser], and Joachim [Akademischer Betreuer] Stahlmann. "Analysis of piles and piled raft foundation under horizontal load / Stefano Stacul ; Betreuer: Joachim Stahlmann." Braunschweig : Technische Universität Braunschweig, 2018. http://d-nb.info/1175815330/34.
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Stacul, Stefano Verfasser], and Joachim [Akademischer Betreuer] [Stahlmann. "Analysis of piles and piled raft foundation under horizontal load / Stefano Stacul ; Betreuer: Joachim Stahlmann." Braunschweig : Technische Universität Braunschweig, 2018. http://nbn-resolving.de/urn:nbn:de:gbv:084-2018061815086.
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Wang, Shenzhi, and 王慎之. "Field monitoring and numerical analysis on piled-raft foundation : case study." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/209499.
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This thesis presents the result of detailed back-analysis, using three-dimensional finite-element analysis, of the instrumented piled-raft foundation in monitoring site. The piled-raft foundation is a composite foundation structure that consisting of piles, raft and surrounding soils acting as a whole system.
To check the reliability of soil taking load under the raft and obtain a reasonable value of load proportion taken by piles for the soil conditions in Hong Kong, a piled-raft foundation was partially instrumented in the monitoring site. The pile head loading, raft-soil contact pressure of specified area and settlement at raft top for selected locations were being monitored. Comparisons of overall settlement, differential settlements and the load carried by the piles show reasonably good agreement.
Followed by a 3D finite element modeling of the entire piled-raft foundation of the monitored site, the analysis includes a pile-soil slip interface model. The numerical analysis is performed to give insights to (1) load transfer behavior of the piled-raft foundation (2) effects of pile reduction on pile load ratio.
Combined the observation from site monitoring and analysis results from the numerical analysis, the proportion of load shared between piles and raft is revealed as 7:3. The lower limit of pile ratio is proposed as 0.67 for the site after the parametric study by removing piles strategically. In spite of the settlement-reducing purpose of the piles, the design of piled-raft foundation still concentrate on providing adequate axial capacity, with settlement requirement treated as a secondary issue. The significance of the study is that it provides factual evidence of soil taking the load under the raft, and the economical benefits of piled-raft foundation as a reduction of piles will save more than 2 million of the construction budgets.<br>published_or_final_version<br>Civil Engineering<br>Master<br>Master of Philosophy
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Saglam, Neslihan. "Settlement Of Piled Rafts: A Critical Review Of The Case Histories And Calculation Methods." Master's thesis, METU, 2003. http://etd.lib.metu.edu.tr/upload/1223379/index.pdf.
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In this study, settlement analysis of pile groups by hand calculation
methods were investigated. Settlement ratio, equivalent pier, and equivalent raft
methods were studied. Variations in some of the calculation methods were noted,
and some suggestions were given.
More than thirty piled raft foundation case histories whose foundation
and soil properties known have been found. The settlement of piled foundation in
each case was solved by these methods. Results obtained from the calculations
following different methods were presented for each case in the form of tables and
graphs. Measured and calculated values were compared by making use of graphs
and tables. Effect of type of piles was shown.
It was tried to find out that which method is suitable under different
conditions. In conclusion, suggestions for methods and calculation procedures
were given.
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Turkmen, Haydar Kursat. "An Experimental Study Into Bearing Of Rigid Piled Rafts Under Vertical Loads." Phd thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609420/index.pdf.
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In this study, the load bearing behavior of piled raft foundations is investigated performing laboratory and field tests. Piled raft foundation of a multi storey building was also instrumented and monitored in order to study the load sharing mechanism of piled raft foundations.
A small reinforced concrete piled raft of 2.3 m square supported by four mini piles at the corners was loaded and contribution of the raft support up to 41 % of the total load was observed. The soil was stiff fissured Ankara clay with no ground water.
A building founded on a piled raft foundation was instrumented and monitored using earth pressure cells beneath the raft during its construction period. The foundation soil was a deep graywacke highly weathered at the upper 10 m with no ground water. The proportion of load that was carried by the raft was 21 to 24 % of the total load near the edge and 44 to 56 % under the core.
In the laboratory tests, model aluminum piles with outerinner diameters of 2218 mm and a length of 200 mm were used. The raft was made of steel plate with plan dimensions of 176 mm x 176 mm and a thickness of 10 mm. The model piles were instrumented with strain gages to monitor pile loads. Model piled raft configurations with different number of piles were tested. The behavior of a single pile and the plain raft were also investigated. The soil in the model tests was half and half sand &ndash<br>kaolinite mixture.
It has been observed that when a piled raft is loaded gradually, piles take more load initially and after they reach their full capacity additional loads are carried by raft. The proportion of load that was carried by the raft decreases with the increasing number of piles and the load per pile is decreased. Center, edge and corner piles are not loaded equally under rafts. It has been found that rafts share foundation loads at such levels that should not be ignored.
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Gaihre, Nirajan. "ANALYTICAL AND NUMERICAL MODELING OF FOUNDATIONS FOR TALL WIND TURBINE IN VARIOUS SOILS." OpenSIUC, 2020. https://opensiuc.lib.siu.edu/theses/2650.
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Wind farm construction is increasing progressively, to cope-up with the current global energy scenario. The advantage of clean energy and sustainability helps wind turbine construction to flourish rapidly. Location of wind turbines is independent of foundation soil condition but depends on the wind speeds and socio-environment issues. Hence, a construction sites may not be favorable in terms of geotechnical demands. The taller wind towers facilitate the generation of high energy production, which will increase loads on the foundation, and eventually increase the dimension of the foundation. Hence, the choice of a suitable foundation system is necessary for geotechnical engineer to design tall wind towers. This study aims to analyze different foundation types e.g., raft/mat foundation, pile group foundation, and piled raft/mat foundation using analytical calculation verified with numerical models using PLAXIS 3D software. The foundation for steel wind turbine towers 100 m high was designed for different types of soils e.g., soft clayey soil, medium-stiff clayey soil, stiff clayey soil, and sandy soil. The design wind speed was taken from the ASCE 7-10 (2010) standard for Occupancy Category III and IV Buildings and Other Structures, as the Illinois region falls in that category. The parametric study was performed by varying the diameter of raft/mat, wind speed, number of piles, and soil types to evaluate the settlement in any type of foundation with load sharing proportion in piled raft/mat foundation. First, the raft/mat foundation design was carried out manually by changing the diameter of 15 m, 20 m, 25 m, 30 m, and 35 m, and changing load by considering different wind speed. Then the foundation was modeled using PLAXIS 3D software with a raft/mat diameter of 25 m, 30 m, and 35 m only, by considering the eccentricity and factor of safety criteria. With the increase in wind speed, the differential settlement on the raft/mat foundation was found to be increased. However, the increase in diameter of raft/mat caused the reduction in differential settlement. Soft clayey soil was found to be more sensitive than other soils used in the present study. For the same diameter of raft/mat, applied the same wind load, the differential settlement of foundation in soft clayey soil was found to be 6-10 times higher than the sandy soil.The position of piles was fixed based on the spacing criteria in the pile group foundation. The number of piles used in this study were 23, 32, and 46. Settlement was found to be varied with the number of piles in all soils used in this study. The lateral deflection for soft clayey soil decreased to half, when number of piles increased from 23 to 46. The differential settlement was found to be increased with the increase in wind speed in pile group foundation. Raft/mat foundation settlement was found to be 4 to 6 times higher than the settlement in pile group foundation in any soils, used in this study, for a given wind speed.The result of piled raft/mat foundation showed that the majority of the total load is shared by the piles (i.e., 60% to 94%) and remaining load is shared by the raft/mat (i.e., 6% to 40%), based on the stiffness of raft/mat and piles as well as pile-soil-pile interaction. The increase in wind speed in the wind turbines increased the differential settlement of piled raft/mat foundation in all soils. Similarly, the lateral deflection also increased with the increase in wind speed in pile raft/mat foundation in all soils. The PLAXIS 3D analysis revealed that the differential settlement in soft clayey soil was 1.5 to 2.0 times higher than the settlement in sandy soil.The validation of numerical modeling was carried out by the raft/mat foundation using Boussinesq’s theory and calculating settlement for single pile and group pile foundation. The current study showed that the soft clayey soil and medium-stiff clayey soil favor deep foundation, like pile group and piled raft/mat rather than shallow foundation, like raft/mat foundation. The results obtained from both analytical calculation and numerical modeling was found to be approximately matching. This study will help local construction company and geotechnical engineer to guide a proper foundation design of tall onshore wind turbine.
Books on the topic "Raft and pile foundation"
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Hwang, Junggeun. Centrifuge Modeling of the Piled Raft Foundation of a High Rise Building. [publisher not identified], 2022.
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Liu, Liu, Zhenming Shi, Ming Peng, Shaojun Li, and Fengjuan Tao. Detection of Karst Voids at Deep Pile Foundation. Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-97-5834-0.
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Brown, D. A. (Dan A.), National Research Council (U.S.). Transportation Research Board, National Cooperative Highway Research Program, American Association of State Highway and Transportation Officials, and United States. Federal Highway Administration, eds. Design guidelines for increasing the lateral resistance of highway-bridge pile foundations by improving weak soils. Transportation Research Board, 2011.
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Bekbasarov, Isabay. Study of the process of driving piles and dies on models. INFRA-M Academic Publishing LLC., 2020. http://dx.doi.org/10.12737/1074097.
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The monograph presents the results of experimental and theoretical studies conducted using models of driven piles and tape dies. The influence of the cross-section size, length, shape of the trunk and the lower end of the piles on their submergability, energy intensity of driving and load-bearing capacity was evaluated. The design and technological features of new types of piles are considered. A method for determining the load-bearing capacity of a pile model based on the results of dynamic tests has been developed. Similarity conditions and formulas are presented that provide modeling of the pile driving process in the laboratory. The influence of the shape of the tape dies on their submersibility, energy consumption of the driving and the bearing capacity of the foundations arranged in the vyshtampovannyh pits was evaluated. The method of determining the load-bearing capacity of a belt Foundation model based on the results of pit vyshtampovyvaniya is described. Recommendations on the choice of optimal parameters of piles and foundations, arranged in vystupovani pits. Recommended for researchers, specialists of design and construction organizations, doctoral students, postgraduates, undergraduates and students of construction and water management specialties.
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Viggiani, Carlo, Alessandro Mandolini, and Gianpiero Russo. Piled Raft Foundations. Taylor & Francis Group, 2013.
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Australia, University of Western, ed. Numerical analysis of piled raft foundations. 1994.
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MITTAL, Satyendra. Pile Foundation Design Construction. CBS Publishers & Distributors, 2017.
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Guyer, J. Paul. Introduction to Pile Foundation Considerations. Independently Published, 2018.
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Practical methods for the analysis of piled raft foundations : computer-aided analysis, design charts, simplified methods. Lambert Academic Publishing, 2009.
Find full textBook chapters on the topic "Raft and pile foundation"
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Reul, Oliver. "Introduction." In Combined Pile-Raft Foundations. CRC Press, 2024. http://dx.doi.org/10.1201/9781003244646-1.
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Reul, Oliver. "Case histories." In Combined Pile-Raft Foundations. CRC Press, 2024. http://dx.doi.org/10.1201/9781003244646-4.
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Reul, Oliver. "Design example." In Combined Pile-Raft Foundations. CRC Press, 2024. http://dx.doi.org/10.1201/9781003244646-5.
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Reul, Oliver. "Bearing behaviour of piled rafts." In Combined Pile-Raft Foundations. CRC Press, 2024. http://dx.doi.org/10.1201/9781003244646-2.
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Reul, Oliver. "Design, construction and monitoring of CPRF." In Combined Pile-Raft Foundations. CRC Press, 2024. http://dx.doi.org/10.1201/9781003244646-3.
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Farid, Ahmed T., and Mostafa A. Yousef. "Enhancement of Raft Foundation Using Micro Pile Technique." In Innovative Solutions for Deep Foundations and Retaining Structures. Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-34190-9_10.
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Golchha, Shreyansh Kumar, Jay Kumar Shukla, and Nitin H. Joshi. "Analysis of Pile Group and Piled Raft as a Foundation System." In Lecture Notes in Civil Engineering. Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-3383-6_66.
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Gupta, Shailja, V. A. Sawant, and P. K. Gupta. "State of the Art on Combined Pile Raft Foundation." In Lecture Notes in Civil Engineering. Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-33-4005-3_14.
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Hamada, Junji, Kiyoshi Yamashita, and Kazutomi Nakane. "Settlement behavior of piled raft foundation supporting residential building adjacent to tall pile foundation building." In Lecture Notes in Civil Engineering. Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-15-2184-3_2.
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Samorodov, O., S. Tabachnikov, O. Dytiuk, et al. "Field investigations of combined raft-pile foundation with adjustable interaction between the raft and the piles." In Geotechnical Engineering Challenges to Meet Current and Emerging Needs of Society. CRC Press, 2024. http://dx.doi.org/10.1201/9781003431749-134.
Full textConference papers on the topic "Raft and pile foundation"
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Sandamal, N. G. T. M., M. T. R. Jayasinghe, and L. I. N. De Silva. "Cellular pile raft foundations for lightweight multi-storey buildings." In Civil Engineering Research Symposium 2024. Department of Civil Engineering, University of Moratuwa, 2024. http://dx.doi.org/10.31705/cers.2024.40.
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The global demand for housing and urban land scarcity has driven the need for multistorey buildings. The substructure design plays a crucial role in ensuring the stability of these structures, as traditional foundation methods, like piled or piled raft foundations, are essential for distributing the substantial loads. However, the high costs associated with these systems have prompted the e ploration of alternative foundation designs This study’s approach seeks to optimize foundation construction by reducing costs without compromising structural integrity, making it a viable solution for sustainable urban development. This study investigates the feasibility of employing a raft foundation, particularly a weight-compensated cellular raft design for multistorey buildings exceeding 10 floors which typically require costly pile foundations. Unlike traditional piles, Backhoe loaders are proposed for constructing piles filled with Aggregate Base Course (ABC) with cement and inserting reinforced columns for anchoring the cellular raft. The strategy involves settling the building slightly to mobilize the soil capacity, particularly for sandy clay soil conditions. Furthermore, the study explores the potential of lightweight superstructures to significantly reduce construction costs by optimizing structural weight and eliminating the need for pile foundations. Specifically, it explores the utilization of Expanded Polystyrene (EPS) based lightweight panels and precast prestressed concrete beam systems with precast prestressed concrete slabs. Investigating a 10-story reinforced concrete moment resisting frame (MRF) supported by a cellular piled raft foundation, the research employs a direct approach considering soil-structure (SSI) interaction effects. Through construction stage analysis using finite element software (Midas GEN, Midas GTS NX), the study determines optimal gap sizes for the cellular raft and assesses the maximum number of storeys feasible without pile foundations. Overall, this study suggests that on sandy clay soil, constructing taller buildings with a maximum of 14 floors, in addition to the cellular basement, is feasible using lightweight superstructures in conjunction with cellular rafts. Moreover, the research recommends increasing pile spacing beyond the current 5m x 5m grid configuration to fully mobilize soil capacity. Future studies should also investigate the effectiveness of these foundation systems across various soil types, including silty clay, loamy soil, and sandy loam, to further validate the design's applicability in different geological conditions.
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MOON, JOON SHIK, and WOOJEONG PARK. "Analysis of Piled Raft Foundation Behavior Considering Raft Pile Soil Interaction." In International Conference on Advances in Civil, Structural and Mechanical Engineering - ACSM 2015. Institute of Research Engineers and Doctors, 2015. http://dx.doi.org/10.15224/978-1-63248-039-2-27.
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Fellenius, Bengt. "US vs EU codes." In DFI-EFFC International Conference on Deep Foundations and Ground Improvement. European Federation of Foundation Contractors and Deep Foundations Institute, 2025. https://doi.org/10.37308/dfieffc25.1650101.
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The forthcoming update of the US AASHTO Specs will agree with the Canadian building code and the US Corps of Engineers code in regard to the analysis and design of piled foundations. Case histories on observations on full-scale piled rafts are reviewed and show that the response of interior and perimeter piles differ. Single piles and perimeter piles engage the soil from the ground downward. In contrast, interior piles engage the soil from the pile toe level upward. Interior piles and soil have strain compatibility, which determines the distribution of load between the piles, the raft contact stress, and the load-transfer movement. Particularly so in subsiding environment, because perimeter piles are subjected to downdrag and drag forces, while neither downdrag nor drag force will affect the interior piles to any appreciable degree. The difference will affect the load distribution and bending moment response across the raft, which is also governed by the degree of rigidity of the raft and by the difference in dishing at the pile toe level and in the dishing of the actual raft. Contact stress under the raft, be it large or small, is incidental to the response of a piled foundation and cannot be considered to reduce the effect of the load applied to the foundation.
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Raju, Devika. "AN EXPERIMENTAL INVESTIGATION ON BEHAVIOUR OF TIMBER PILE GROUPS IN SANDY SOIL." In International Conference on Innovations in Computing Materials & Communication Technologies. San International Scientific Publications, 2023. http://dx.doi.org/10.59646/proceedings/003.
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Pile raft foundation is relatively new approach for design of pile group in which pile cap was considered in contact with soil and designed as raft that transfer partial load of superstructure to soil. The design of pile raft foundation is no t a simple problem as many interaction effect as pile to pile, pile to soil, pile to raft and raft to soil are involved and effect the design considerable. In this study, an experimental investigation has been carried out on a sufficiently large model in laboratory to observe the effect of various parameters such as effect on load carrying capacity of pile raft on diameter, length of pile, pile surface roughness, relative density of sand. A Timber piles can also be driven for ground improvement, to densify loose granular soils.
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Leppla, Steffen, and Arnoldas Norkus. "ON APPLICATION OF COMBINED PILE-RAFT FOUNDATIONS FOR ROAD STRUCTURES." In 11th International Conference “Environmental Engineering”. VGTU Technika, 2020. http://dx.doi.org/10.3846/enviro.2020.829.
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Roads and road infrastructure systems are designed to satisfy ultimate and serviceability conditions under long-term actions caused by transport loadings and environmental effects. Selected design solutions must be safe and rational in terms of construction and maintenance costs. In cases when weak or soft soil layers of natural soil profiles are shallow and/or the traffic loads are very large, the Combined Pile-Raft Foundation (CPRF) is the economical road and railway structure design solution. Application of CPRF is cheaper geotechnical solution comparing with soil change or usual piled foundation alternatives. The development of this system is based on the analysis of relevant mechanical properties of soil layers and the evaluation of the soil-structure interaction. The soil-structure interaction is of highest importance allowing proper evaluation of load bearing resistance and deformation transmitted by raft and piles to soil layers. The soil and foundation system usually is subjected by loadings, resulting elastic-plastic resistance range. Therefore, relevant nonlinear physical laws due to the stress levels are used. The paper purpose is summarizing the experience of application of Combined Pile-Raft Foundations used in road and railway construction and bridge engineering.
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Cao Van, Hoa, and Tuan Nguyen Anh. "Establishing a Graphical Method for Calculation of Raft Thickness in Piled Raft, Pile Group and Raft Foundation." In 2020 3rd International Conference on Information and Computer Technologies (ICICT). IEEE, 2020. http://dx.doi.org/10.1109/icict50521.2020.00056.
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Ravichandran, P. T., K. Divya Krishnan, and R. Lokeswaran. "Performance of disconnected pile raft foundation in cohesionless soil." In ADVANCEMENTS IN MATERIALS FOR CIVIL ENGINEERING APPLICATIONS. AIP Publishing, 2024. http://dx.doi.org/10.1063/5.0236820.
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Konovalov, Roman I. "CALCULATION OF COMBINED PILE-RAFT FOUNDATIONS." In III Научно-практическая конференция аспирантов и молодых ученых АО «НИЦ «Строительство». АО «НИЦ «Строительство», 2023. http://dx.doi.org/10.37538/2713-1157-2023-44-46.
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Saady, Semaa Z. Al, and Mahdi Karkush. "Comparison review between behavior of connected and disconnected pile raft foundation." In PROCEEDINGS OF THE INTERNATIONAL CONFERENCE ON RESEARCH ADVANCES IN ENGINEERING AND TECHNOLOGY - ITechCET 2022. AIP Publishing, 2024. http://dx.doi.org/10.1063/5.0186106.
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Saha, Rajib, Sekhar Chandra Dutta, and Sumanta Haldar. "Influence of SSI on Soil-Pile Raft-Structure System: An Experimental Study." In International Symposium on Advances in Foundation Engineering. Research Publishing Services, 2013. http://dx.doi.org/10.3850/978-981-07-4623-0_158.
Full textReports on the topic "Raft and pile foundation"
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Wang, Yao, Jeehee Lim, Rodrigo Salgado, Monica Prezzi, and Jeremy Hunter. Pile Stability Analysis in Soft or Loose Soils: Guidance on Foundation Design Assumptions with Respect to Loose or Soft Soil Effects on Pile Lateral Capacity and Stability. Purdue University, 2022. http://dx.doi.org/10.5703/1288284317387.
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The design of laterally loaded piles is often done in practice using the p-y method with API p-y curves representing the behavior of soil at discretized points along the pile length. To account for pile-soil-pile interaction in pile groups, AASHTO (2020) proposes the use of p-multipliers to modify the p-y curves. In this research, we explored, in depth, the design of lateral loaded piles and pile groups using both the Finite Element (FE) method and the p-y method to determine under what conditions pile stability problems were likely to occur. The analyses considered a wide range of design scenarios, including pile diameters ranging from 0.36 m (14.17 inches) to 1.0 m (39.37 inches), pile lengths ranging from 10 m (32.81 ft) to 20 m (65.62 ft), uniform and multilayered soil profiles containing weak soil layers of loose sand or normally consolidated (NC) clay, lateral load eccentricity ranging from 0 m to 10 m (32.81 ft), combined axial and lateral loads, three different pile group configurations (1×5, 2×5, and 3×5), pile spacings ranging from 3 to 5 times the pile diameter, two different load directions (“strong” direction and “weak” direction), and two different pile cap types (free-standing and soil-supported pile caps). Based on the FEA results, we proposed new p-y curve equations for clay and sand. We also examined the behavior of the individual piles in the pile groups and found that the moment applied to the pile cap is partly transferred to the individual piles as moments, which is contrary to the assumption often made that moments are fully absorbed by axial loads on the group piles. This weakens the response of the piles to lateral loading because a smaller lateral pressure is required to produce a given deflection when moments are transferred to the head of the piles as moments. When the p-y method is used without consideration of the transferred moments, unconservative designs result. Based on the FEA results, we proposed both a new set of p-multipliers and a new method to use when moment distribution between piles is not known, using pile efficiency instead to calculate the total capacity of pile groups.
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Nevarez Garibaldi, Roberto. Comparison between Linear and Staggered Pile Configurations For Slope Stabilization. Deep Foundations Institute, 2025. https://doi.org/10.37308/cpf-2023-land-rr.
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The paper addresses slope stabilization through use of deep foundation elements (for simplicity, we refer to them generically as “piles” throughout this paper) and particularly focuses on the efficiency of linear versus staggered arrangements of piles along a slope. The study investigates the impact of pile arrangement on shear resistance, assuming constant soil properties, pile size, and reinforcement. The research employs Slope/W and Group software for slope stability analysis and reinforcement design; however, the analysis procedure detailed in this paper can be applied to other applicable programs such as Slide, LPile, etc. This paper defines and addresses use of piles to mitigate slope instability and soil flow between piles. The design procedure involves initially modeling a stable slope that is close to failure. Piles configured in linear and staggered alignments, with varying spacing, are then applied to the model to increase the shear resistance along the potential sliding surfaces. Lastly, through a Group analysis, pile arrangement efficiency is evaluated. Results from this research indicate that a linear arrangement of piles is more efficient than a staggered arrangement
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Han, Fei, Monica Prezzi, Rodrigo Salgado, Mehdi Marashi, Timothy Wells, and Mir Zaheer. Verification of Bridge Foundation Design Assumptions and Calculations. Purdue University, 2020. http://dx.doi.org/10.5703/1288284317084.
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The Sagamore Parkway Bridge consists of twin parallel bridges over the Wabash River in Lafayette, IN. The old steel-truss eastbound bridge was demolished in November 2016 and replaced by a new seven-span concrete bridge. The new bridge consists of two end-bents (bent 1 and bent 8) and six interior piers (pier 2 to pier 7) that are founded on closed-ended and open-ended driven pipe piles, respectively. During bridge construction, one of the bridge piers (pier 7) and its foundation elements were selected for instrumentation for monitoring the long-term response of the bridge to dead and live loads. The main goals of the project were (1) to compare the design bridge loads (dead and live loads) with the actual measured loads and (2) to study the transfer of the superstructure loads to the foundation and the load distribution among the piles in the group. This report presents in detail the site investigation data, the instrumentation schemes used for load and settlement measurements, and the response of the bridge pier and its foundation to dead and live loads at different stages during and after bridge construction. The measurement results include the load-settlement curves of the bridge pier and the piles supporting it, the load transferred from the bridge pier to its foundation, the bearing capacity of the pile cap, the load eccentricity, and the distribution of loads within the pier’s cross section and among the individual piles in the group. The measured dead and live loads are compared with those estimated in bridge design.
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Wang, Wei, Michael Brown, Matteo Ciantia, and Yaseen Sharif. DEM simulation of cyclic tests on an offshore screw pile for floating wind. University of Dundee, 2021. http://dx.doi.org/10.20933/100001231.
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Screw piles need to be upscaled for offshore use e.g. being an alternative foundation and anchor form for offshore floating wind turbines, although the high demand of vertical installation forces could prevent its application if conventional pitch-matched installation is used. Recent studies, using numerical and centrifuge physical tests, indicated that the vertical installation force can be reduced by adopting over-flighting which also improved axial uplift capacity of the screw pile. The current study extends the scope to axial cyclic performance with respect to the installation approach. Using quasi-static discrete element method (DEM) simulation it was found that the over-flighted screw pile showed a lower displacement accumulation rate, compared to a pitch-matched installed pile, in terms of load-controlled cyclic tests. Sensitivity analysis of the setup of the cyclic loading servo shows the maximum velocity during the tests should be limited to avoid significant exaggeration of the pile displacement accumulation but this may lead to very high run durations.
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Ebeling, Robert, Barry White, John Hite та ін. Load and resistance factors from reliability analysis Probability of Unsatisfactory Performance (PUP) of flood mitigation, batter pile-founded T-Walls given a target reliability index (𝛽). Engineer Research and Development Center (U.S.), 2023. http://dx.doi.org/10.21079/11681/47245.
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This technical report documents the research and development (R&D) study in support of the development of a combined Load and Resistance Factor Design (LRFD) methodology that accommodates both geotechnical and structural design limit states for design of the US Army Corps of Engineers (USACE) batter pile-founded, reinforced concrete flood walls. Development of the required reliability and corresponding LRFD procedures has been progressing slowly in the geotechnical topic area as compared to those for structural limit state considerations, and therefore this has been the focus of this first-phase R&D effort. This R&D effort extends reliability procedures developed for other non-USACE structural systems, primarily bridges and buildings, for use in the design of batter pile-founded USACE flood walls. Because the foundation system includes batter piles under flood loading, the design procedure involves frame analysis with significant soil structure interaction. Three example batter pile-founded T-Wall flood structures on three different rivers have been examined considering 10 geotechnical and structural limit states. Numerical procedures have been extended to develop precise multiple limit state Reliability calculations and for complete LRFD analysis of the example batter pile-founded, T-Wall reinforced concrete, flood walls.
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Breland, Benjamin, Janet Simms, William Doll, Jason Greenwood, and Ronald Kaufman. Waterborne geophysical investigation to assess condition of grouted foundation : Old River Control Complex – Low Sill Structure, Concordia Parish, Louisiana. Engineer Research and Development Center (U.S.), 2022. http://dx.doi.org/10.21079/11681/44183.
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The Old River Low Sill Structure (ORLSS) at the Old River Control Complex (ORCC) in Concordia Parish, LA, is a steel pile-founded, gated reinforced-concrete structure that regulates the flow of water into the Atchafalaya River to prevent an avulsion between the Mississippi River and the Atchafalaya River. A scour hole that formed on the southeast wall of ORLSS during the Mississippi River flood of 1973 was remediated with riprap placement and varied mixtures of self-leveling, highly pumpable grout. Non-invasive waterborne geophysical surveys were used to evaluate the distribution and condition of the grout within the remediated scour area. Highly conductive areas were identified from the surveys that were interpreted to consist mostly of grout. Resistive responses, likely representing mostly riprap and/or sediment, were encountered near the remediated scour area periphery. A complex mixture of materials in the remediated scour area is interpreted by the more gradual transitions in the geophysical response. Survey measurements immediately beneath ORLSS were impeded by the abundance of steel along with the structure itself. The survey results and interpretation provide a better understanding of the subsurface properties of ORLSS.
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Turner, Benjamin. Guidance for Factoring Deep Foundation Structural Resistance for Landslide Stabilization and Excavation Support. Deep Foundations Institute, 2023. http://dx.doi.org/10.37308/cpf-2017-land-1.
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Lateral support provided by deep foundations can be an effective means to stabilize existing and potential landslides, and deep foundations contribute to the stability of support-of-excavation systems. However, defining the structural resistance and implementing it in a slope stability analysis that satisfies LRFD requirements is a source of significant confusion and miscommunication among geotechnical and structural designers. This report explains the implications of applying (or not) structural resistance factors at various stages of the analysis. Furthermore, most commercial slope stability software offers the option to either use the user-input structural resistance without reducing it by the slope stability factor of safety (“Method A”) or to reduce the structural resistance by the stability factor of safety (“Method B”). Applying a structural resistance factor and/or using Method B will result in designs requiring more structural reinforcement; however, it is not necessarily the case that doing so will significantly improve reliability (i.e., decrease the probability of failure) of the slope. Three example cases are presented and analyzed probabilistically to demonstrate how reliability is influenced by the chosen method for factoring structural resistance, and the various scenarios for which this may or may not represent a tangible improvement in reliability from the slope Owner’s perspective. A recommended approach for factoring and implementing deep foundation structural resistance in slope stability analyses is described along with a simple example. After initial stability analyses are run without the deep foundations to define the critical surface geometry, p-y method lateral pile-soil interaction analyses are performed to identify the controlling strength limit state and corresponding mobilized shear resistance at the intersection of the deep foundation and critical slide surface. Because this mobilized resistance is limited by the factored shear and flexural strength of the foundation element, it represents a factored resistance, and inherently satisfies LRFD structural design requirements. This factored resistance is input back into the slope stability analyses using Method A such that no additional factoring is applied to the structural resistance; the stability analyses must then satisfy a minimum factor of safety, typically in the range of 1.3 to 1.5. The AASHTO LRFD Bridge Design Specifications prescribe that the global stability factor of safety is interpreted as the reciprocal of the geotechnical resistance factor, and that the load factor for global stability is 1.0. Hence, the recommended approach satisfies structural and geotechnical LRFD requirements.
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Marinucci, Antonio. ACIP Pile Installation, Installation Monitoring, Full-scale Load Testing, and Extraction Program. Deep Foundations Institute, 2017. http://dx.doi.org/10.37308/cpf-2016-acip-1.
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The Augered Cast-In-Place (ACIP) Pile Committee of the Deep Foundations Institute (DFI) performed a foundation installation, monitoring, performance and extraction program for ACIP piles in the fall of 2016. The purpose of the project was to demonstrate a fully monitored installation of instrumented 18 in (457 mm) and 24 in (610 mm) diameter ACIP piles, including automated monitoring equipment (AME); post-installation thermal integrity profiling (TIP) measurements; compression, tension, and lateral load testing (including monitoring of strain gages embedded along the compression pile shaft); and post-testing extraction of an installed pile for visual inspection. The program was initially planned by the ACIP Pile Committee, and a program site in Okahumpka, FL was selected. Initial funding was provided by the DFI Committee Project Fund with additional funds andin-kind pledges contributed from DFI members and industry partners. In the summer of 2016, the FloridaDepartment of Transportation (FDOT) and its research partners at the University of South Florida (USF)joined the program. Program details were finalized in the summer and fall of 2016. The purposes of this research effort were to demonstrate The fully monitored installation of instrumented ACIP piles, including the use of automated monitoring equipment (AME); The use and accuracy of thermal integrity profiling (TIP) methods with ACIP piles; The load-displacement behavior during compression, tension, and lateral load testing, including the use of and measurement by multiple strain gages embedded along the length of two piles; The integrity and as-constructed geometry of an ACIP pile by extracting an installed pile for visual inspection. To achieve the goals of the project, seven test piles were installed at a site in central Florida: two each for compression testing, tension testing, and lateral testing, and one pile for extraction and visual inspection. The intent of this document is to make the data and information obtained during the demonstration program available to the members of the DFI ACIP Pile Committee, Florida DOT, University of South Florida, and other possible research partners for review, analysis/interpretation, and discussion. The ultimate goals of this endeavor are to advance the overall state-of-the-practice for ACIP piles and to develop documentation for review and use; installation, monitoring, and testing methods; and reporting procedures to allow for both the use of ACIP piles for structural support of bridges and the inclusion of ACIP piles in DOT and other agency specifications in the state of Florida and elsewhere. All of the data presented and discussed herein can be made available in electronic format for additional analysis. Pertinent findings of the demonstration project include the following: The procedures and testing results described in the report highlight the successful installation, monitoring, and load carrying resistance provided by ACIP piles for structural support of bridges per the Florida DOT. The data can be used by the FL DOT as it develops a section for ACIP Piles for Bridges and Major Structures in its Standard Specifications; Grout volumes, as measured by an electromagnetic flowmeter and via manual counting of grout strokes, were in good agreement with each other; The overall grout volume of the extracted pile, when adjusted for the volume of grout observed flowing out of the top of the pile, was in good agreement with the volume calculated by manually measuring the circumference of the extracted pile at 1 ft (305 mm) intervals; Additional research into non-destructive testing (NDT) methods for ACIP piles, in particular Thermal Integrity Profiling, should produce a means to provide additional verification of pile integrity.
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Raja, Rameez Ali, Mustafa Kilic, Monica Prezzi, Rodrigo Salgado, and Fei Han. Implementation Study: Continuous, Wireless Data Collection and Monitoring of the Sagamore Parkway Bridge. Purdue University, 2022. http://dx.doi.org/10.5703/1288284317367.
Full textAbstract:
This report presents, in detail, the development and implementation of a wireless solar powered DAQ system for continuous real-time monitoring of the Sagamore Parkway Bridge using the data collected from strain gauges installed in the bridge pier and its foundation piles. The data analysis showed that there is no significant change in the load-settlement response of the bridge pier 3 years after its construction. The pile cap contribution in carrying the total load carried by the bridge pier is significant (about 20%). The hourly ambient temperature trends match with the incremental bending moments measured on the bridge pier and the piles. The daily temperature cycles also affected the load transferred between the piles within the pile group. The water level fluctuations of the Wabash River impacted the total load carried by the pier, such that a rise in water level resulted in slight drop in the total load carried by the bridge pier due to buoyant forces. The overall results of the bridge monitoring showed that the bridge has performed well since its construction.
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Niazi, Fawad. CPT-Based Geotechnical Design Manual, Volume 1: CPT Interpretation—Estimation of Soil Properties. Purdue University, 2022. http://dx.doi.org/10.5703/1288284317346.
Full textAbstract:
This manual provides guidance on how to use the cone penetration test (CPT) for site investigation and foundation design. The manual has been organized into three volumes. Volume 1 covers the execution of CPT-based site investigations and presents a comprehensive literature review of CPT-based soil behavior type (SBT) charts and estimation of soil variables from CPT results. Volume 2 covers the methods and equations needed for CPT data interpretation and foundation design in different soil types, while Volume 3 includes several example problems (based on instrumented case histories) with detailed, step-by-step calculations to demonstrate the application of the design methods. The methods included in the manual are current, reliable, and demonstrably the best available for Indiana geology based on extensive CPT research carried out during the past two decades. The design of shallow and pile foundations in the manual is based on the load and resistance factor design (LRFD) framework. The manual also indicates areas of low reliability and limited knowledge, which can be used as indicators for future research.