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Variation of pile head displacement versus pile diameter in nonlinear analyses for (a) sand and (b) clay with constant EI for the pile.
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The nonlinear behavior of a laterally loaded monopile foundation is studied using the finite element method (FEM) to account for soil-pile interactions. Three-dimensional (3D) finite element modeling is a convenient and reliable approach to account for the continuity of the soil mass and the nonlinearity of the soil-pile interactions. Existing simp...
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Citations
... The integration point, positioned at the element's centre, ensures the most precise stress and strain measurements at the integration points. By implementing hourglass control, zero energy modes are eliminated effectively, preventing significant displacements from interfering with the accurate solution (George et al., 2020;Khodair & Abdel-Mohti, 2014;Mardfekri et al., 2013). The mechanical properties of the cohesionless soil and pile are shown in Table 3. ...
This paper presents an experimental and numerical investigation of RCC (Reinforced Concrete) piles with helical grooves under axial and lateral loads in cohesionless soil. A set of experiments is carried out to assess the performance of RCC piles with helical grooves. To replicate the experimental findings, the Finite Element Method (FEM) is employed using Abaqus software. Three-dimensional (3D) models are created to represent both the pile and the soil using Abaqus. The paper compares settlement characteristics and lateral displacement of plain RCC piles and RCC piles with helical grooves. This study also evaluates the impact of varying the pitch of helical grooves on enhancing pile performance. The results indicate that RCC piles with helical grooves outperform plain RCC piles in terms of both axial and lateral load-carrying capacity, inferred from both experimental and analytical techniques.
... For similar magnitude lateral loads, the pile head deflection (PHD) for a group of piles was inferred to be larger than for a single pile. The influence of sloping ground as well as the different types of loads on the pile/pile group response has been studied by several researchers [2,[12][13][14][15][16][17][18] through extensive experimental and numerical studies. The deformation of the pile was inferred to be increasing substantially with an increase in the slope of the ground [19,20]. ...
Generally, pile foundations are used in offshore
structures to resist huge lateral loads, which can be inferred
as a result of wind, waves, earthquakes, and moving trains.
The sloping grounds vary from gentle slopes in case of
mooring platforms or berthing structures to steeper slopes in
case of transmission towers to be erected on hilly or mountainous
areas. Hence, it is critical to analyse the response of
piles on varying slopes and also the interaction between the
soil and pile at different slopes. The current study aims to
understand the behaviour of single pile and pile groups on
the sloping ground under varying static lateral loads. A parametric
study is conducted on model aluminium piles embedded
in uniform sand stratum with varying pile configurations
(single pile and 2 × 2 pile group), aspect ratio (12, 25, 40),
pile spacing (3D and 5D), lateral load (forward and reverse
directions), and slope (horizontal, 1V:3H and 1V:5H). The
effect of slope, load deflection, and bending moment characteristics
of the pile was examined under different loading
circumstances. The forward lateral load condition implies a
significant reduction in the pile lateral load capacity; single
piles showed percentage reductions of 60%, 48%, and 40%,
while the 2 × 2 pile group for 3D spacing showed reductions
of 70%, 52, and 48%. The effect of slope, load deflection, and bending moment characteristics of the pile was examined
under different static lateral loading directions.
... Although the P-y model was used in previous studies, it needs to be improved if we are considering the pile vibration and soil detachment [27]. Therefore, some new pilesoil interaction models have been put forward to overcome the shortcomings of the P-y model [28][29][30][31][32][33]. Among these proposed models, the Goodman contact element model is able to consider the displacement discontinuity of the contact interfaces, which has good applicability in pile-soil interaction simulations [33]. ...
... Therefore, some new pilesoil interaction models have been put forward to overcome the shortcomings of the P-y model [28][29][30][31][32][33]. Among these proposed models, the Goodman contact element model is able to consider the displacement discontinuity of the contact interfaces, which has good applicability in pile-soil interaction simulations [33]. Therefore, numerical simulations were carried out in this paper to assess the influence of pile-soil contact models on the lateral dynamic bearing capacity of deepwater conductors. ...
... Although the P-y model was used in previous studies, it needs to be improved if we are considering the pile vibration and soil detachment [27]. Therefore, some new pile-soil interaction models have been put forward to overcome the shortcomings of the P-y model [28][29][30][31][32][33]. Among these proposed models, the Goodman contact element model is able to consider the displacement discontinuity of the contact interfaces, which has good applicability in pile-soil interaction simulations [33]. ...
It is important to accurately assess the interaction between the conductor and the soil to ensure the stability of the subsea wellheads during deepwater drilling. In this paper, numerical simulations were carried out to study the lateral dynamic bearing capacity of the conductor considering different contact models between the conductor and the soil. In particular, the contact surface model and contact element model were selected to study the dynamic behavior of pile–soil under a transverse periodic load. On this basis, the influence of the bending moment, the wellhead stick-up, the outer diameter (O.D.) of the conductor and the wall thickness (W.T.) of the conductor, as well as the physical parameters of the soil on the dynamic bearing capacity are discussed in detail. Analysis results show that the lateral deformation, deflection angle and von Mises stress calculated by the contact element model are greater than those calculated by the contact surface model. The maximum value of the lateral deformation and bending moment of the conductor decrease with the O.D. and W.T. of the conductor, and the cohesion and internal friction angle of the soil. However, the maximum value of the lateral deformation and bending moment of the conductor increase with the wellhead stick-up. Both the vertical force and the soil density have a negligible effect on the lateral behavior of the conductor. This study has reference value for the design and stability assessment of subsea wellheads.
... Numerical simulations were performed to improve the analysis of the experimental data, allowing to understand the system's mechanics in terms of load distribution, raft tilting, and horizontal subgrade reactions among trailing and leading piles. Among the different types of numerical methodologies developed to the analysis of piled rafts under lateral and combined loads (Small and Zhang 2002;Ashour and Norris 2004;Hirai 2012;Mardfekri et al. 2013;Comodromos et al. 2016), three-dimensional finite element analysis (3D FEA) were adopted due to its capacity to model more details of the physical problem, especially the ones concerning the pile damaged zone. ...
The present paper aims to investigate the effects of defective piles in horizontally loaded piled raft foundations. Close to real scale foundation models of defective and intact three-piled systems were submitted to horizontal load tests. The models used bored type piles drilled with 5 m in length and 0.25 m in diameter, connected to a concrete raft founded on a tropical soil profile at the University of Campinas research site. Based on the experimental data, a three-dimensional finite element analysis was initially calibrated and consequently used to study the effects of the defective element at the pile load distribution and the horizontal subgrade forces at the pile shaft. The results show that the presence of a defective pile increases the raft tilting, which affects both vertical and horizontal load distributions among the raft and the piles, and among trailing and leading piles.
... The FE method provides the capability of considering continuity of the soil mass, appropriate nonlinear material models for both the pile and geologic substrate, defining different boundary conditions and nonlinear interaction effects necessary to model the soil-pile contact problems. Kim et al. [24], Mardfekri et al. [25], Strömblad [26], Salim [27], and Youssouf et al. [28] have employed three-dimensional FE methods to study the effect of soil-pile interaction on laterally loaded piles. Senturk et al. [29] performed threedimensional finite element push-over analyses of bridge piers considering the nonlinear behavior of reinforced concrete and soil under quasi-static loading. ...
... There are different material models available in Abaqus™ that can be used to model the pile-soil interaction. However, in this paper, the most commonly used Mohr-Coulomb plasticity model [25,30] was used to depict the nonlinear behavior of soil. The Mohr-Coulomb yield criteria assumes that a yield function is governed by the maximum shear stress that depends on the normal stress. ...
... There are different material models available in Abaqus™ that can be used to model the pilesoil interaction. However, in this paper, the most commonly used Mohr-Coulomb plasticity model [25,30] was used to depict the nonlinear behavior of soil. The Mohr-Coulomb yield criteria assumes that a yield function is governed by the maximum shear stress that depends on the normal stress. ...
Scour, caused by swiftly moving water, can remove alluvial sediment and soil, creating holes surrounding a bridge component and compromising the integrity of the bridge structure. Such problems can be equally critical for bridges with piers-on-bank bridges subjected to severe storm and flooding issues. In this paper, the Phillips Road Bridge over Toby Creek (35°18′28.2″ N 80°44′16.6″ W, Charlotte, NC, USA), a pier-on-bank bridge with critical/significant local scour holes and deep riverbank erosion cuts was selected as case study bridge. To investigate the scour effect on the bridge with pier-on-bank performance, the scoured area around a single pier is first quantified using a terrestrial laser and then modeled using nonlinear finite element (FE) analysis, where the local scour is modeled as progressive mass losses using the Element Removal (ER) technique. The FE results are compared to the design loading scenario and the results substantiated that the local scouring could cause large deflection and increased bending moment on the bridge pier.
... However, the p-y method and the more classical beam on Winkler foundation methods do not consider the three-dimensional nature of the pile-soil behavior and its effect on the performance of the pile. As a result, more robust FE methods have been used: Mardfekri et al. [33], Strömblad [34], Salim [35] and Youssouf et al. [36], are some of the studies that employed three-dimensional FE methods to study the effect of soil-pile interaction on laterally loaded piles. Senturk and Pul [37] performed three-dimensional finite element push-over analyses of bridge piers considering the nonlinear behavior of reinforced concrete and soil under quasi-static loading. ...
This paper examines the scour problems related to piers-on-bank bridges resulting from frequently flooded and/or constricted waterways. While local scour problems for bridge piers in riverine channels have been addressed extensively in the literature, there have been few studies addressing piers-on-bank scour scenarios. A comprehensive three-dimensional finite element analysis using the element removal (ER) technique has been performed on a recently constructed bridge with an observable scour problem on multiple piers. The analysis is further extended to study the effect of “combined scour” or extensive erosion of soil between adjacent piles. Three different loading cases were considered in the study, and the results demonstrated that the effects of local and combined scours on bridge drilled shaft foundations can be significant under the combined actions of axial, lateral loads and bending moments. Specifically, the most critical case of combined scour is when maximum moment effect is applied to the piers. The results of this study show that the interaction of soil displacement fields between adjacent piles should be investigated for bridge crossings with piers-on-bank, with a high risk of flooding during the moderate-to-low probability of the occurrence of precipitation events, as they can increase the pile head displacements and the bending moments in the soil and result in the early failure of bridges.
... The soil formation in these areas expected to have very low strength, low bearing capacity and expected high settlements above the allowable limits [1]. Many studies were performed around the world regarding characterization, ISSN: 0011-9342 | Year 2021 Issue: 6 | Pages: 2189 -2207 [2191] attempted to study the behavior of piles under lateral load [27], [28], [29], [30] and [31] using 3D finite element analysis. In view of the above-mentioned issues, this paper presents and discusses the results of a series of 3D finite element analyses carried out using ADINA software (version 9.6) in order to recapitulate and to evaluate numerically the influence of vertical loads on the lateral performance of piles as well as internal forces of piles installed in the North-Eastern Egyptian coast, which extended from Port-Said area to the north the Nile river delta. ...
Construction on weak soil formations is a challenge for geotechnical engineers. Such formations are found in the coastal areas and can be found in many places all over the world. In Egypt, coastal soil is located in the northeast region which consists of a shallow surface layer of soft clay followed by a layer of loose sand overlaying a deep soft clay layer. Construction on such soil is a challenge due to the existence of a thick soft clay layer with low bearing capacity. Using deep foundations in such soil formation will end bear at depths greater than 50 m, which is too expensive, especially for light weight structures. This study aims at using relatively short friction piles under structures. These short piles will be constructed and bear in the upper loose to medium dense sand layer. The idea of using friction piles in loose to medium dense sand under both vertical and lateral loads is to work as settlement reducing piles. To study this idea detailed 3D numerical analysis is performed using software ADINA to analyze and study the behavior of piles in such problematic soil, accounting for the effect of the presence of deep soft clay layers.
... Xu et al. [7,8] proposed a modified strain wedge model for the nonlinear analysis of laterally loaded single piles in sandy soils and determined the effect of low-plasticity fines on the lateral response of piles in sand. The displacement of a concrete bored pile under a lateral load is nonlinear [9][10][11]. The ultimate contact pressure behind the pile is different between the stiff shaft and the flexible shaft, depending on soil cohesion. ...
The Yuanzishan landslide is an unstable slope in Langzhong County, located in northeast Sichuan province, China. The Guangyuan-Nanchong expressway passes through the front edge of the unstable slope, and subgrade excavation has resulted in slope deformation, which threatens the safety of the highway construction. Emergency landslide control requires reduction of the slope disturbance. This study aims to investigate the use of buried-boring piles as a potential method for emergency landslide control. A simplified calculation method was used for the design of the buried-boring piles, according to the limit equilibrium of the soil and the elastic foundation coefficient method. The measured internal force changes of the pile were compared, in order to determine the distribution coefficients of the driving force. A relationship between the driving force of the shared pile ratio and the buried depth ratios was then established. Furthermore, a variety of factors affecting the internal forces of the buried-boring pile and the lateral reaction of the soil were also studied. The results revealed that (1) there was a quadratic relationship between the driving force of the pile-shared ratio and the sliding depth ratios; (2) the maximum bending moment of the pile increased with an increase in the sliding depth ratio of the pile, following a power law relationship; (3) increasing the buried depth of the pile head reduced the influence of the pile diameter on the maximum internal forces; (4) increasing the pile diameter decreased the maximum lateral reaction of the soil. The buried-boring piles can be used in similarly unstable regions for emergency control of deforming slopes.
... ue of the reference modulus, 4. Failure zones developed around the pile propagate to greater lateral distances and greater depths with decreasing the thickness of the upper loose sand layer, and 5. Contrary to the assumption made by conventional methods, the distribution of the lateral effective stresses is not linear along the pile embedded depth.Mardfekri et al. (2013), performed analyses of a single pile, taking into account nonlinear soil-pile interaction and the results compared with some ...
Construction on weak soils has been a challenge for geotechnical engineers for decades. Building on such soft soil formations induces excessive immediate and long-term settlements, in addition to their low bearing capacity. Weak soils are located at different zones of the world, and at the north of the Nile delta in Egypt , especially Port-Said. The soil in parts of the northeast region of Egypt consists of a surface layer with a small depth of soft clay followed by a layer of loose to medium dense sand with some of broken seashells overlaying a deep layer of soft clay. Using deep foundations in such soil formation will end bear at depths starting from 30 to 60 m, which is too costly, especially for light weight structures. In some cases, the structure loads are light enough to be supported by shallow foundations employing thick layers of soil replacement, which is generally accompanied by dewatering to relatively large depths in high permeability soils.
This research aims to use relatively short friction piles to support such relatively low structure loads, avoiding the use of soil replacement and dewatering. These short piles will be constructed and bear in the upper loose to medium dense sand layer without going through the deep soft clay layers and finally ending at the very deep dense sand layer to reduce construction costs. The idea of using friction piles in loose to medium dense sand is somewhat not common, especially in sand. In the case of the current soil stratification, using friction piles is an economic attractive alternative and needs to be studied and analyzed in details to account for the effect of the presence of the underlying deep soft clay layers. In this thesis, numerical analysis is performed using software ADINA (Version 9.6.) to analyze and study the behavior of piles in such problematic soil formation.
... The diffusion of FEM for pile foundation applications is still limited by several modelling complexities (especially in the case of pile group and CPRF under lateral loading, which are non-axisymmetric problems), and as shown in Mardfekri et al. (2013) FEM calculations are influenced by even minor details of the modelling of the pile and its interface. ...
A new code, called PRaFULL (Piled Raft Foundation Under Lateral Load), was developed for the analysis of laterally loaded Combined Pile Raft Foundation (CPRF). The proposed code considers the contribution offered by the raft-soil contact and the interactions between all the CPRF system components. The nonlinear behaviour of the reinforced concrete pile and the soil are accounted. As shallower soil layers are of great relevance in the lateral response of a pile foundation, PRaFULL includes the possibility to consider layered soil profiles with appropriate properties. The shadowing effect on the ultimate soil pressure is accounted, when dealing with pile groups, as proposed by the Strain Wedge Model. PRaFULL BEM code obviously requires less computational resources compared to FEM (Finite Element Method) or FDM (Finite Difference Method) codes. The proposed code was validated in the linear elastic range by comparisons with the code APRAF (Analysis of Piled Raft Foundations). The reliability of the procedure to predict piled raft performance was then verified in nonlinear range by comparisons with both centrifuge tests and computer code PRAB.
