Numerical analysis of pile installation effects in cohesive soils (original) (raw)
Related papers
Studia Geotechnica et Mechanica, 2017
In this paper, the whole process of pile construction and performance during loading is modelled via large deformation finite element methods such as Coupled Eulerian Lagrangian (CEL) and Updated Lagrangian (UL). Numerical study consists of installation process, consolidation phase and following pile static load test (SLT). The Poznań site is chosen as the reference location for the numerical analysis, where series of pile SLTs have been performed in highly overconsolidated clay (OCR ≈ 12). The results of numerical analysis are compared with corresponding field tests and with so-called "wish-in-place" numerical model of pile, where no installation effects are taken into account. The advantages of using large deformation numerical analysis are presented and its application to the pile designing is shown.
Large Deformation Finite Element Analysis of Undrained Pile Installation
Studia Geotechnica et Mechanica, 2016
In this paper, a numerical undrained analysis of pile jacking into the subsoil using Abaqus software suit has been presented. Two different approaches, including traditional Finite Element Method (FEM) and Arbitrary Lagrangian–Eulerian (ALE) formulation, were tested. In the first method, the soil was modelled as a two-phase medium and effective stress analysis was performed. In the second one (ALE), a single-phase medium was assumed and total stress analysis was carried out. The fitting between effective stress parameters and total stress parameters has been presented and both solutions have been compared. The results, discussion and verification of numerical analyzes have been introduced. Possible applications and limitations of large deformation modelling techniques have been explained.
Capacity estimation of Pile by Numerical modelling
Zenodo (CERN European Organization for Nuclear Research), 2022
Estimation of Pile capacity has been one of the major challenging issues for geotechnical engineers in Bangladesh. Although various analytical and empirical methods and codes of practices are available to estimate the axial capacity of piles, the estimation has to be supported by pile load test results. However, in practice, being a costly, time-consuming, and risky approach, the number of pile load tests specified by code of practices is often truncated in many projects. Besides, a rigorous understanding of soil mechanics, local geology, and experiences are needed for the efficacious design of piles. This study focuses on estimation of load capacity and soil settlement for piles using the numerical modeling. A finite element based software, PLAXIS-3D, has been used for modelling of piles, to simulate pile load test for piles in this study. Four piles, having various dimensions and located at different parts of the country, are modelled to estimate load capacities. Those piles capacities are also estimated using different static and dynamic methods to validate the estimated pile capacities using PLAXIS model. For simplicity, for the shake of general practitioners, soils and concrete piles are modeled using Mohr-Coulomb, and Linear-elastic material models. The axial load capacity of the piles are estimated by different commonly practiced methods to determine pile capacity in Bangladesh (α or total stress method, β or effective stress method, λ or semi-empirical method, and BNBC 2020, based on SPT N value). Shear strength parameters of soils beneath and surrounding the pile are estimated based on empirical correlations based on SPT N value. Then, pile load tests are carried out for those Four piles to corroborate the load capacity and settlement values estimated by numerical modeling and other methods. The study shows that results from numerical modeling are agreeable with pile load test results and other commonly used methods. Therefore, numerical modeling of piles, which is easy to accommodate, could help the practicing engineers to design piles confidently and cost-effectively because the load-settlement behavior of all piles of the projects can be simulated using the numerical model. It could also decrease the number of pile load tests required for large projects and thus reduce the cost of the foundation.
Canadian Geotechnical Journal, 2015
During pile installation, the stresses and void ratios in the surrounding soils change significantly, creating large strains, soil distortion and excess porewater pressures. This makes the numerical modeling of pile installation process using finite element (FE) method a challenging task. In this paper, the pile installation process and the subsequent consolidation and load tests conducted at different times after end of driving were modeled for the Bayou Laccassine Bridge site. In the FE model, the pile was considered as an elastic material, and the modified cam-clay model was used to describe the behavior of the surrounding clayey soils. The surface to surface masterslave contact model was used to simulate the pile-soil interface. Pile installation was modeled by applying prescribed radial and vertical displacements on nodes at the soil-pile interface (volumetric cavity explanation), followed by vertical movement to activate the soil-pile interface friction. The results from the FE numerical simulation included porewater pressure generation and dissipation with time, increasing of effective normal stress at the pile-soil interface, and the setup ratios at different times. The results are compared with measured values obtained from the full-scale load tests on concrete piles, which showed good agreement.
2D and 3D Numerical Simulation of Load-Settlement Behaviour of Axially Loaded Pile Foundations
Reliable prediction of settlement behaviour of axially loaded piles is one of the major concerns in geotechnical engineering. Therefore, this paper focuses on the finite element solutions of load-settlement behaviour of a single pile and pile group using PLAXIS numerical package. Three different types of analysis were incorporated: a linear elastic analysis, a complete nonlinear analysis and a combined analysis. The pile case history with settlement measurements made during field pile load test was considered to validate the single pile load-settlement simulation, and the same load test result was extended to simulate the load-settlement behaviour of pile group using RATZ analytical approach. The single pile analysis results suggest that realistic load-settlement predictions can be drawn by considering complete soil as Mohr-Coulomb model at lower working loads, and incorporation of an interface zone thickness of two times pile diameter using Hardening-Soil model is required to simulate the load-settlement behaviour at higher working loads. The group pile analysis results provide a better load-settlement prediction when incorporating an interface zone thickness of pile dimeter from the pile shat using Hardening-Soil model while leaving the remaining soil as Linear-Elastic material.
Numerical simulation of pile installation
Computers and Geotechnics, 2011
During installation of a displacement pile, the soil around the pile is heavily distorted. The resulting changes in soil density and stress state around the pile determine the ultimate pile capacity. In most finite element models, the installation phase is not explicitly modelled. In this paper the full installation phase is modelled in two different ways, in a numerical code capable of large deformations.
Numerical Modelling and Bearing Capacity Analysis of Pile Foundation
Procedia Engineering, 2015
The problem of designing deep foundations is related to many civil engineering structures as it is becoming more common and frequent to construct buildings on soft soils. Pile foundation is a popular deep foundation type used to transfer superstructure load into subsoil and bearing layers. However, accurate prediction of piles' settlement is particularly difficult concerning complicated consolidation process and pile-soil interaction. The objective of this paper is to model a soil-pile system using FEM implemented in Abaqus software. The numerical results of pile bearing capacity and pile settlement were compared with static load test results of CFA piles carried d with engineering analytical calculations according to Eurocode 7 and Polish Standard Code.
Numerical Evaluation of Pile Response Under Combined Lateral and Axial Loading
Geotechnical and Geological Engineering
Piled foundations are frequently subjected to simultaneous axial and lateral loadings. However, the interaction effects of the one loading on the other are, in most cases, disregarded for the sake of simplicity. With the aim of evaluating this effect, a detailed research work on the response of a single pile under simultaneous application of axial and lateral loading was carried out. A qualitative assessment of the effect was initially attempted and the effect was afterwards quantified, based on the results of an intensive three-dimensional parametric numerical analysis. The influence arising from pile head fixity and the second order phenomenon was examined, while the post-peak behaviour was also considered using a strain hardening/softening constitutive law. Interesting conclusions have been drawn, providing a qualitative and quantitative evaluation of the effect on clayey and sandy soils. It was also found that no loading interaction effect is developed, when ultimate limit state is applied for a piled foundation design. On the contrary, when the serviceability limit state is applied and if the pile capacity in both lateral and axial loading is simultaneously reached, a reduction in the pile axial capacity is observed in the case of clayey soils. On the contrary, in the case of sandy soils the action of a lateral load is leading to an increase of pile axial capacity.
Approximation of pile installation effects: a practical tool
Proceedings of the ICE - Geotechnical Engineering, 2015
ç improvement factor ó rr , ó zz , ó ŁŁ , ó rz Cartesian stresses ö c critical friction angle of the soil ł ł rr ,ł ł zz ,ł ł ŁŁ ,ł ł rz ,ł ł e model functions of Cartesian stress and void ratio fields Geotechnical Engineering Approximation of pile installation effects: a practical tool Engin, Brinkgreve and Van Tol Offprint provided courtesy of www.icevirtuallibrary.com Author copy for personal use, not for distribution Geotechnical Engineering Approximation of pile installation effects: a practical tool Engin, Brinkgreve and Van Tol Offprint provided courtesy of www.icevirtuallibrary.com Author copy for personal use, not for distribution Geotechnical Engineering Approximation of pile installation effects: a practical tool Engin, Brinkgreve and Van Tol Offprint provided courtesy of www.icevirtuallibrary.com Author copy for personal use, not for distribution Geotechnical Engineering Approximation of pile installation effects: a practical tool Engin, Brinkgreve and Van Tol Offprint provided courtesy of www.icevirtuallibrary.com Author copy for personal use, not for distribution Geotechnical Engineering Approximation of pile installation effects: a practical tool Engin, Brinkgreve and Van Tol
Numerical Analysis of Pile–Soil Interaction under Axial and Lateral Loads
International Journal of Concrete Structures and Materials, 2014
In this paper, the analysis of a numerical study of pile-soil interaction subjected to axial and lateral loads is presented. An analysis of the composite pile-soil system was performed using the finite difference (FD) software LPILE. Two three dimensional, finite element (FE) models of pile-soil interaction have been developed using Abaqus/Cae and SAP2000 to study the effect of lateral loading on pile embedded in clay. A lateral displacement of 2 cm was applied to the top of the pile, which is embedded into the concrete pile cap, while maintaining a zero slope in a guided fixation. A comparison between the bending moments and lateral displacements along the depth of the pile obtained from the FD solutions and FE was performed. A parametric study was conducted to study the effect of crucial design parameters such as the soil's modulus of elasticity, radius of the soil surrounding the pile in Abaqus/Cae, and the number of springs in SAP2000. A close correlation is found between the results obtained by the FE models and the FD solution. The results indicated that increasing the amount of clay surrounding the piles reduces the induced bending moments and lateral displacements in the piles and hence increases its capacity to resist lateral loading.