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Ontwerpmethode voor een proefbelasting van palen, mede naar aanleiding van problemen met funderingen in het Meer van Maracaibo, Venezuela, en in de Golf van Mexico.

Due to the weak soil deposits in the Netherlands, pile foundations consisting of driven displacement piles are often used to support the superstructure. The influence of pile installation process on the stresses and the soil properties is large. In geotechnical practise the effect of the pile installation and the interaction with neighbouring structures is of special interest. These type of geotechnical problems are commonly investigated with the aid of numerical methods, i.e. the finite element method (FEM). Numerical simulation of the pile installation process requires a constitutive model which is able to describe the soil behaviour, taking into account the continuously changing soil properties. In the current study the use of the hypoplasticity constitutive model in an Eulerian frame- work, offered by the commercial package FEAT, is adopted. Hypoplasticity has emerged in the recent years and is gaining popularity due to its numerous successfull applications. It is an inelastic (dissipative) and incrementally nonlinear constitutive model, which requires neither a yield surface nor a decomposition of strain rate into elastic and plastic portions. It presents a single tensorial equation holding equally for loading and unloading. This research is formulated to gain more knowledge into the experimental determination of the hypoplasticity model parameters, leading to the derivation of a consistent parameter set for Baskarp sand. The hypoplasticity parameters for Baskarp sand are of special interest such that the numerical simulation of the soil behaviour can be compared with the measurements obtained from two model tests of displacement piles installed in a geotechnical centrifuge. The outcome of this thesis will provide an unambiguous procedure to determine the hypoplasticity model parameters. The parameter set derived for Baskarp sand can be used to validate and improve the numerical simulation of the model pile tests performed by Dijkstra et al. (2006). The experimental work starts with the characterisation tests, i.e. grain size distribution, mass density, maximum and minimum void ratios. Next, a series of oedometric and drained triaxial compression tests were carried out on loose and dense samples. In addition image processing techniques are introduced for the determination of the angle of repose.

Piles subjected to horizontal soil displacements are a common phenomenon at constructions next to soil embankments, for example an abutment of a bridge. Shell factors play an important role in the analysis of these piles with 2-dimensional (2D) design methods. This study investigates if the limitations of a 2D method, in relation to the 3-dimensional reality, can be covered by shell factors. Starting points for this study were the conclusions from the recently published CUR-report 228: Ontwerprichtlijn door grond horizontaal belaste palen. First, by a literature study and an analysis of current 2D-methods, the role of shell factors in these methods is investigated. It appears that shell factors are being used in different ways, to take care of different 2D limitations, depending on the method. In current design practice, this difference in function of the shell factor is often not taken care of. Second, a PLAXIS 2D finite element model is made to calculate shell factors. With this model a parameterstudy is been executed, in which the influence of the following parameters on the value of the shell factor is been determined: • Horizontal soil stress; • Soil parameters: soil stiffness, cohesion and angle of internal friction; • Pile diameter and pile shape; • Size of the relative pile-soil displacement. A single pile is being considered, and time-dependant factors (consolidation and creep) are being neglected. Finally, a calculation is made with a 2D method, with calculated shell factors. The results are validated on the measurements of a laboratory test. From the study, it can be concluded that it is possible to make good predictions of bending moments in piles, with the use of correct shell factors. Because the study is executed with a 2D model, validation with a 3D finite element method is necessary. Further investigation of the time-dependant aspects, such as creep, is highly recommended.

Bij de kademuren die de laatste jaren in de diepere havens van Nederland gemaakt zijn, wordt de grand gekeerd door combiwanden. Dit is voor de hier gerdende grondopbouw en belastingen de meest geschikte constructievorm, deze wordt hier als 'conventionele methode' gezien. Een alternatieve manier om de grand te keren is de diepwand. Deze techniek wordt in Nederland relatief weinig gebruikt, voor kademuren is deze in diepe havens zelfs nog nooit toegepast. In de havens van de landen om ons heen, zoals Le Havre, Antwerpen en Hamburg wordt echter wel regelmatig voor de diepwand gekozen. Bij een toenemende havendiepte moeten de kerende wanden zwaarder en langer worden, wat bij de combiwanden tot problemen bij het heien leidt. Voor diepwanden geldt dat een gratere doorsnede of diepte nauwelijks extra moeilijkheden met zich meebrengt, zodat verwacht kan worden dat bij extreme omstandigheden de diepwand goedkoper is. In dit afstudeerpraject is voor de Amazonehaven op de Maasvrakte onderzocht in hoeverre dit, voor de havendiepten die in de nabije toekomst nodig zijn, kan leiden tot constructies waarbij de diepwand het goedkopere alternatief oplevert. Verder zijn redenen aangedragen waarom in de ons omringende landen de kademuren met diepwanden wel goedkoper kunnen zijn dan met combiwanden. Om de eerste doelstelling (Kan de diepwand voor de Amazonehaven in de nabije toekomst goedkoper zijn?) te bewerkstelligen zijn allereerst de conventionele typen en grondopbouw gemodelleerd en berekend (bodemniveau NAP. -18.50 m). De gegevens die hieruit volgen (veiligheden, deformaties) dienen als leidraad voor de ontwerpen waarbij de grond door diepwanden gekeerd wordt. Voor de diepwand-varianten zijn alternatieven opgesteld, waarvan de 6 meest reele vormen zijn gedimensioneerd. Bij de berekeningen van de eerste varianten zijn analyses gemaakt van het gedrag van de wanden bij verschillende inklemmingen, wandstijfheden en ankerstijfheden. De uitkomsten hiervan zijn op de overige alternatieven toegepast zodat het ontwerpen sneller kon geschieden. Uit de analyses blijkt dat de stijfheid van de verankering weinig invloed heeft op de optredende ankerkrachten en momenten in de wand, maar dat de verhouding van de stijfheid van de wand en de ankers wel de vorm van deformeren be;·nvloedt. Aangezien de deformaties geen maatgevend criterium vormen is deze invloed van klein belang. Verder bleek dat de mate van inklemming in de grond weliswaar een grate invloed heeft op het momentverloop in de wand maar dat per situatie (optredende maximale momenten en gekozen wanddikte) de optimale verhouding tussen de te produceren hoeveelheid diepwand en benodigde wapening moet worden gezocht. Uit de begrotingen van de gedimensioneerde alternatieven blijkt dat MV-palen aanzienlijk efficienter dat ankerstaven met -schermen zijn. Tevens is dUidelijk geworden dat varianten met een ontlastkoker boven de diepwanden verreweg de goedkoopste alternatieven zijn. Na de keuze van het ontwerp is gepoogd de kosten van dit alternatief te verlagen door de wand stijf te verbinden met de koker. Door deze 'verende inklemming' wordt het moment in het veld van de wand gereduceerd, voor het beschouwde bodemniveau (NAP. -18.50 m) is dit echter niet effectief. De extra wapening door het inklemmingsmoment is meer dan de vermindering van de wapening door de reductie van het veldmoment. Het gekozen diepwand-concept wordt vervolgens ook voor diepere havens gedimensioneerd, namelijk met een bodem op NAP. -21.50 m en NAP. -24.50 m. Voor de combiwand-varianten is dit eveneens gedaan om een vergelijking mogelijk te maken. De berekeningen van de diepere havens zijn voor beide wand-typen ook uitgevoerd met een hogere ontlastkoker. De duurdere koker maakt een kortere en minder zwaar belaste wand mogelijk, waardoor in sommige gevallen de totale kosten dalen.

Een paalrij bestaat uit naast elkaar aangebrachte vertikale palen of balken en staat als geheel loodrecht op de kust. De geometrie van paalrijen (in bovenaanzicht) komt overeen met die van stenen strandhoofden. Het primaire doel van paalrijen is het reduceren van het langstransport, waardoor een eventuele erosie wordt verminderd of een aanwas wordt bereikt. Sinds het midden van de jaren zestig is het aantal paalrijen gestadig uitgebreid. Deze uitbreiding vloeit onder meer voort uit positieve ervaringen met reeds geplaatste paalrijen en het feit, dat paalrijen betrekkelijk eenvoudig en goedkoop kunnen worden gekonstrueerd. Dit verslag beschrijft een theoretisch onderzoek naar verschijnselen, die zich voordoen na plaatsing van paalrijen in een kustgebied. Op de eerste plaats wordt aandacht besteed aan de invloed van paalrijen op de waterbeweging, waarbij het accent ligt op de verandering van de langsstroomsnelheid. Daartoe worden bewegingsvergelijkingen afgeleid bij diverse stroomtoestanden die als representatief voor een kustgebied mogen worden beschouwd (o.a. getijstromen, brandingsstromen). Teneinde het effekt van paalrijen op het sedimenttransport te bepalen, zijn voor een aantal stroomtoestanden transportberekeningen uitgevoerd. Een vergelijking tussen het transport in situaties met en zonder paalrijen levert een indikatie t.a.v. morfologische veranderingen.

In cases where the sheet pilling is allowed, when great retaining heights have to be achieved a combined quay wall structure is normally used. This structure consists of a sheet pile wall, a relieving platform, an anchor and a pile foundation system. The content of the present MSc thesis is divided into two major parts. The first part (Part A0 contains mostly hand calculations for the determination of the loads and for the analysis of the sheet pile wall, while on the second part (Part B) advanced computer programs will be used for the same purpose. A parametric analysis of seven different quay walls is investigated, for various loading combinations of given loads. In details, three different depths and two different widths of the relieving platform were investigated. In addition a quay wall combined only from sheet piles, without a relieving platform is also analysed. 1)The sheet pile wall, in Part A, is analysed by three different approaching theories of Blum. The fixity of the end point of the sheet piling is considered once as completely free and in the other two as fully fixed. Graphs concerning the effect of the various dimensions of the relieving platform, the embedded depth and the anchor force are produced. 2)In the Elastic Supported Beam theory (Msheet) analysis the ground is simulated according to a more advanced model. According to that theory, the Sheet Pile Wall is schematised as a beam on an elastic foundation, where the ground is simulated by a set of uncoupled elasto-plastic springs. 3)In Part B, the Finite Elements Method. PLAXIS created from Plaxis is used for that purpose. This type of analysis is based on a model in which the behaviour of soil and structure are integrated. Through a parametric analysis and a financial assessment of a quay wall, the economic effects of the relieving platform separately on the sheet pile wall and on the whole structure is estimated.

A thesis presented on the comparison between different geotechnical models for single piles, which are loaded laterally at the top, on the basis of field measurements. The considered models are Blum, Brinch Hansen, Broms, the Characteristic Load Method, the Nondimensional Method, the Single Pile Module of MSheet, p-y Analysis by MPile and Finite Element Analysis by Plaxis.

Jetgroutkolommen worden gevormd door onder hoge druk een groutmengsel in de grond te injecteren. De grond wordt versneden, losgewoeld en vermengd met de gernjecteerde vloeistof. Door de boorbuis roterend te trekken ontstaat een cilindervormig element. Afbankelijk van het gekozen systeem geschiedt het snijden met dezelfde of met een andere straal dan het mengen. Gesproken wordt van het 1, 2 of 3 fase(n) systeem jetgrouten. De jetgroutkolommen kunnen na uitharding worden gebruikt als waterremmend en/of constructief element. Jetgrouten kan in iedere grondsoort worden toegepast. De ervaring in Nederland met de jetgroutechniek is beperkt tot enkele werken. Visser & Smit Bouw is vooralsnog de enige aannemer in Nederland die beschikt over het benodigde materieeI. De diameter en de sterkte van de kolom worden bepaald door de uitvoeringsparameters en de grondeigenschappen, samen de invoerparameters van het systeem. Onder de uitvoeringsparameters wordt verstaan de injectiedruk, het injectiedebiet, de luchtdruk, de treksnelheid, rotatiesnelheid e.d. De belangrijke grondeigenschappen zijn de cohesie, de dichtheid en het poriengehaIte. De moeilijkheid bij de techniek betreft het voorspeIIen van het resultaat (diameter en sterkte) op basis van de invoerparameters. Het doel van dit onderzoek is tweezijdig. Enerzijds is gezocht naar verbanden en relaties tussen de invoerparameters en het resultaat en anderzijds is gekeken naar de uitvoeringsaspecten van de techniek. Dit laatste betreft ook een meetmethode voor de diameter tijdens de uitvoering van de kolommen. In het kader van de bouw van een tramtunnel in het centrum van Den Haag, het zogenaamde Souterrain, is een uitgebreide jetgroutproef op ware grootte uitgevoerd. Het doel van de proef was het bepalen van de uitvoeringsparameters voor het maken van een groutboog die de waterafsluiting aan de onderzijde van de bouwput vormt. Het 2 en 3 fasen systeem is beproefd, waarbij gevarieerd is met injectiedrukken, debieten, treksnelheden en water/cement-factoren. Tijdens de uitvoering zijn met behulp van een spinapparaat diameterbepalingen gedaan en zijn verse monsters aan de kolom en retourspoeling onttrokken. Na uitharding van de proefkolommen is de put ontgraven, zodat het resultaat kon worden bestudeerd. Vit de kolommen zijn kernen geboord die aan druk- en splijttesten zijn onderworpen. Dit verslag bevat de beschrijving en de analyse van de jetgroutproef. Onderscheid is gemaakt tussen volumieke massa en sterkte van de verschilIende monsters en de diameter van de kolom. Het jetgroutproces is te complex om te komen tot een aIIes omvattend rekenkundig verband tussen het resultaat en de invoer. Het grote probleem blijft het betrekken van de eigenschappen van de grond in een berekening. Toch zijn enkele interessante bevindingen gedaan. De belangrijkste bevinding is de relatie tussen de invoer en het diameterresultaat via de begrippen hydraulische of kinetische energie van de snijstraaI. De hydraulische energie wordt berekend met de snijdruk, het snijdebiet en de treksnelheid, terwijl de kinetische energie wordt berekend met de massa en snelheid van de vloeistof en de treksnelheid. Indien de energiesoorten tegen de diameter worden uitgezet, ontstaat een energiekromme. Deze kromme ligt voor ieder systeem en grondsoort anders en kan worden gebruikt bij het vaststelIen en vergelijken van de uitvoeringsparameters. Voordat met een jetgroutwerk wordt begonnen moet een grondonderzoek worden uitgevoerd, zodat de grondeigenschappen over het te grouten traject in kaart gebracht kunnen worden. Op deze wijze kan tijdens het jetgrouten worden geanticipeerd op wijzigingen in bodemgesteldheid, zodat de kwaliteit van de kolommen gehandhaafd blijft. Met behulp van diameterbepalingen met bijvoorbeeld een spinapparaat kan de diameter vlak na het jetgrouten worden gemeten.

Non-breaking wave forces on a cylindrical pile are calculated numerically by solving the three-dimensional Navier Stokes equations in the numerical wave tank of REEF3D. Initially, the numerical wave tank is validated by comparison of the numerical results with the analytical solutions for varying grid density, time step size, numerical beach width, wave amplitude, numerical methods- time and spatial discretization, relaxation method and wave type. The performance of the wave tank under the aforementioned various conditions is observed. As a result the appropriate parameters to be used for the numerical experiment are obtained. Finally, simulations are carried out to calculate the wave forces on a cylindrical pile and the numerical results are compared to the results obtained using the Morison formula. During validation, it is observed that the wave tank gives good results with an error of 0.24% in the wave amplitude at a grid density of 100 cells per wavelength and CFL number 0.1 for a fifth order Stokes wave of amplitude 0.05m and wavelength 2m. A recent study using a different approach reported a requirement of 200 cells per wavelength. Thus, the performance of the wave tank in this study is considered very good. The calculation of wave forces also shows promising results. The wave forces from REEF3D seem to be slightly under estimated compared to the Morison force in the four numerical experiments carried out. There exists a possibility of erroneous calculation of the Morison force. There were no instabilities in the solution from the numerical calculations. Due to the absence of simple experimental data for wave force on a cylinder and time constraints, validation is attempted only through Morison formula by adding the formula in the code. The validation of wave force calculation could not be deemed conclusive.

This research focuses on the behaviour of a granular scour protection around piles when the bed is subjected to bed degradation. Furthermore, engineering guidelines are provided to account for bed degradation in the design of the initial scour protection. To address the behaviour of the protection, a physical model is used and to obtain the engineering guidelines, a theoretical approach is used which includes the phenomena that are observed during the physical model tests. As stated by many authors [Breusers et al., 1991; Chiew, 2004; Melville et al., 2000], a granular scour protection around a pile can fail due to several mechanisms. In clear-water conditions these mechanisms include shear failure, winnowing and edge scour and in live-bed conditions two other mechanisms can be added, namely bed degradation and bed form induced failure. This research focuses on the bed degradation mechanism, which can endanger the granular scour protection around a pile. Just like Van der Hoeven [2002] observed during his research on falling aprons, the stones spread evenly over the front and side slopes of the mound, which form after undermining of the protection has led to the ‘falling’ of the edge stones of the protection. This coverage of stones on the slopes of the mound effectively rearmoured the slopes and prevented further erosion. At the back of the mound this rearmouring is not observed, because the high turbulence levels, introduced by both the mound and the pile, caused stones to become unstable in this area. Furthermore, at the front and side slopes, where the slope of the mound was totally covered by the stones of the protection, the slope angles were constant and comparable to the slope angles that Van der Hoeven found in his research, namely 1:2,0. However, a remarkable difference between the observations of Van der Hoeven and the observations of the current research concerns the layer thickness of the protection on the slope. Van der Hoeven observed that the layer thickness after launching of the apron was only 1*df,50 thick, while the current observations show a decreasing layer thickness from the top of the slope to the toe of the mound. The theoretical approach that is used to develop a design formula focuses on the side slopes, where the flow is parallel to the interface between stones and base material. A balance between the volume of the initial protection and the required volume of stones after bed degradation has led to the formulation of the internal slope angle, γ. This angle describes the assumed linearly decreasing thickness along the slope, starting with a certain required thickness at the top, Df,A, to a thickness of only 1*df,50 at the bottom. Because the hydraulic load decreases with increasing distance from the pile and the thickness of the initial protection is based on the maximum load near the pile, the assumption that Df,A is equal to the initial thickness of the protection, leads to a conservative design formula. This approach is however taken in the development of the simplified design formula, which results in a linear relation between the bed degradation and the extra extent of the initial protection that should be constructed to deal with that bed degradation.

The aim of this research was to examine the use of grouting methods for pile foundation improvement, a generic term that is used here to define both foundation renovation (increasing the bearing capacity of a pile foundation that has insufficient bearing capacity) and foundation protection (safeguarding the piles of the foundation against possible damage resulting from underground construction activities in the vicinity). A full-scale test, of which the general set-up and consistency check are outlined in the thesis, examining the feasibility of foundation improvement by means of grouting techniques was conducted in Amsterdam. The main part of the thesis focuses on permeation grouting, jet grouting and compaction grouting. For each method, first some more general aspects like history, grouting equipment, grouting parameters and fields of application are outlined. Subsequently existing theories used in modelling the grouting process are examined and compared. The test results are discussed. By using the pile displacements, soil stresses, pore pressures and pile bearing capacity measured in the test, it was possible to examine the influence of grouting methods on pile foundations. The use of and suitability of geophysical verification methods for grouting, which were necessary to determine the shape and position of grouted elements, were also considered. To determine how grouting methods can best be applied for foundation renovation purposes, the cost of grouting methods and the hindrance that they cause have been compared with those of conventional foundation renovation methods. The construction cost of grouting can be up to about 50% lower than that of conventional methods of underpinning a structure. Taking cost, hindrance and the test results into consideration, it can be concluded that permeation grouting and compaction grouting are economic and effective alternatives to conventional underpinning methods for renovating pile foundations. The methods may also be used for pile foundation protection. Jet grouting is only suitable for use in the renovation of end bearing piles when the structure is strong and stiff enough to redistribute the loads from the grouted pile. Jet grouting is very suitable for use in protecting pile foundations because it can be applied in any type of soil.

Rapid and static load tests were conducted on open-ended and close-ended piles in the Deltares GeoCentriflige. hi flight, a pile was driven into the soil. Both fme-grained sand and silt beds were tested. Both the rapid and static soil resistances o f a close-ended pile were higher than the soil resistance o f an open-end pile in both sand and silt. For the rapid load test, the higher the penefration rate, the higher the maximum soil resistance. The rado o f maximum soil resistance between a rapid load test and static load test does not depend on pile type but on soil type: less than 1.0 for sand and higher than 1.0 for silt. The results show that centrifiige modeling can be applied for open-ended piles but then silt must be used as the soil material.

When a pile is driven into soil, the soil is pushed away which results in significant changes in both stress state and strain state. Using Finite Element Code to simulate the pile installation process has been not yet completely successful partly due to the limited knowledge of the governing behavior of the soil around a displacement pile. An investigation into the soil behavior during a static installation of a jacked-in pile in dry sand is conducted in this research. The mechanism of pile installation is studied under a plane strain condition. A measurement method based on (1) digital photography and (2) digital image correlation was applied to observe the soil deformation around the pile during installation. Series of simple tests were performed and proved that the method offers sufficient accuracy concurrent with large number of measurement points within the observation area. A series of four pile installation tests, with stress controlled on the top boundary, is conducted. The influence of initial void ratio and an additional surcharge on soil deformation was examined. The resulting displacement field was used to deduce the strain field around the pile and strain paths during pile installation process. The rigid/nearly-rigid cone of soil is found under the pile tip. Zone of high high volumetric strain and high shear strain locates below the cone and radially extends with respect to the cone. That a zone of high volumetric strain and considerable shear strain occurs along the pile shaft during continued penetration suggests an existence of the shear band. The inwards relaxation of soil elements near the pile shaft is confirmed by the tail at the end of the displacement trajectories and the peak of rotation paths in loose condition. The steady state deformation is also observed in loose assembly only.

Pile testing, which plays an importance role in the field of deep foundation design, is performed by static and non-static methods to provide information about the following issues: (Poulos, 1998) - The ultimate capacity of a single pile. - The load-displacement behavior of a pile. - The performance of a pile during the test conditions. - The integrity of a pile (pile integrity test). For the purposes of verification the design axial capacity and the static load – settlement behavior of piles, the static pile load test has long been considered as the most reliable method but because of its high cost and time consuming, non – static pile load tests are looked as efficient substitutions. The two non – static testing methods, i.e. dynamic and quasi – static pile load test are objects of this report. The non – static pile load tests are performed by means of exerting an impact force on the pile head while measuring and recording the responses of the pile, from which the test results are determined. Duration of the impact force (T), longitudinal wave velocity of tested pile (c) and pile length (L) are used as key factors to classify the testing methods.

In this paper, dislocation climb is incorporated in a two-dimensional discrete dislocation dynamics model. Calculations are carried out for polycrystalline thin films, passivated on one or both surfaces. Climb allows dislocations to escape from dislocation pile-ups and reduces the strain-hardening rate, especially for fully passivated films. Within the framework of this model, climb modifies the dislocation structures that develop during plastic deformation and results in the formation of pile-ups on slip planes that do not contain any dislocation sources.

Pile load tests are commonly used by engineers to determine its bearing capacity. At present, there are three methods of pile load tests: the static, the dynamic and the quasi-static test. The static pile load test is done by applying an axial load on the pile with a long duration. The dynamic and quasi-static tests are done with an impact load on pile head of very short duration. However, the required force pulse in the quasi-static test is longer than in the dynamic test. This research focuses on the comparison between quasi-static and static tests. An important aspect in order to verify the results of quasi-static application with respect to more widely used static loading. The results of quasi-static tests have both static and dynamic components. Then, in order to convert the results of a quasi-static test to static pile bearing capacity, the dynamic component (inertial and damping effects) in the soil responses have to be understood. The effect of generates pore water pressure and its dissipation during pile penetration are unclear and can limit the interpretation of the results of a quasi-static test.

During vibratory sheet piling quite often the soil near the sheet pile wall will settle. In many cases this is not a problem. For situations with houses, pipelines, roads or railroads at relative short distance these settlements may not be acceptable. The purpose of the research described in this thesis is to develop a model that is capable of predicting the settlement due to vibratory sheet piling with reasonable accuracy. The research is limited to sheet piling in sand. First a description is given of the processes during vibratory sheet piling. From this description the main mechanisms that are responsible for the settlement during vibratory sheet piling are identified. These are the densification of the soil and the displacement of a soil volume due to the volume of the sheet pile. Presently available models to predict the settlement are described and commented. It is concluded that all models possess some shortcomings. As densification is one of the main causes for the settlement much attention is paid to the behaviour of sand during cyclic loading. Available models to predict the densification for large numbers of loading cycles are described. Attention is paid to the combined effect of generation and dissipation of excess pore pressure. To supplement the findings from the literature a series of cyclic triaxial tests is performed to clarify some aspects. These tests show that the history of the sand greatly influences the behaviour during cyclic loading. A numerical model is developed that takes into account the different sub processes during vibratory sheet piling (interface behaviour sheet pile - soil, propagation of vibrations, densification, dissipation excess pore pressure and summation of the local volume strains). For the propagation and the densification different options are considered and implemented. The selected constitutive models are extended to handle both undrained and drained soil behaviour. To validate the developed model a well instrumented field test is designed and executed. This test is performed at Raamsdonksveer, The Netherlands. Measured data are the vibrations near the sheet pile, the pore pressure, the local densification, the settlement at surface and at two depths and the change in cone resistance. The measured data are processed and interpreted. In addition to the results of this test, measured surface settlements from a number of projects are used as well to compare predictions with the developed model with actual behaviour. A reasonable agreement between measured and predicted settlement is found.

Pile foundations are widely used, mainly to transmit structural load to an underlying stiffer soil or rock. This limit state load a certain pile can sustain without failure is known as pile ultimate bearing capacity. During design stage load-tests are performed in-situ on test piles to determine, among others, the value of the bearing capacity. Commonly static tests are performed as they provide the most reliable data. Dynamic tests are much more cost-effective but have a series of shortcomings, mainly the fact that they introduce stress-waves on the pile and that require calibration with the static values. To overcome both nature-kind problems, a new type of test in-between the previous ones, i.e. the pseudostatic test, has been developed. It is still a dynamic test but the loading pulse lasts longer (70-150ms), 20 times the dynamic pulse, emphasizing the static component. Hence, it is both an economical and reliable option as requires no calibration with the static load-displacement curves. Therefore, it is interesting to get more insight on it. Two main factors can influence the bearing capacity of a pile measured on the in-situ tests, namely, loading rate and excess pore pressures. In cases like The Netherlands, where end-bearing piles are driven into saturated sand, these two concepts may play an important role. A previous study had been carried out in dry sand and did not find a remarkable loading rate effect. However, for the case of saturated sand the soil response remains unknown. This research investigates the topic, the objective is to get more insight on the excess pore pressure generation and dissipation, evaluate the static-pseudostatic correlation and investigate the possibility of providing effective predictive tools. The research has been structured in three parts. First a series of experimental scaled tests have been carried out for three loading rates: a CPT (20 mm/s), a static test (1 mm/s) and a pseudostatic test (up to 250 mm/s). The sample consisted in saturated sand that was prepared by means of a fluidizaton-vibration system. Standard sounding rots with a piezocone acted as the pile; five values were recorded: force on the pile head, shaft friction, tip resistance, displacement and acceleration. Later on, the performed scaled tests have been modeled analytically and numerically. An analytical model based on the cone model of Wolf has been developed. Only the soil underneath the pile tip is considered and it is modeled as an elastoplastic material under static fully undrained loading followed by consolidation. PLAXIS is the program used for the numerical model.