Development of Curves of Laterally Loaded Piles in Cohesionless Soil (original) (raw)
Related papers
Development of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1">mml:mipmml:mtext-mml:miyCurves of Laterally Loaded Piles in Cohesionless Soil
The Scientific World Journal, 2014
The research on damages of structures that are supported by deep foundations has been quite intensive in the past decade. Kinematic interaction in soil-pile interaction is evaluated based on the p-y curve approach. Existing p-y curves have considered the effects of relative density on soil-pile interaction in sandy soil. The roughness influence of the surface wall pile on p-y curves has not been emphasized sufficiently. The presented study was performed to develop a series of p-y curves for single piles through comprehensive experimental investigations. Modification factors were studied, namely, the effects of relative density and roughness of the wall surface of pile. The model tests were subjected to lateral load in Johor Bahru sand. The new p-y curves were evaluated based on the experimental data and were compared to the existing p-y curves. The soil-pile reaction for various relative density (from 30% to 75%) was increased in the range of 40-95% for a smooth pile at a small displacement and 90% at a large displacement. For rough pile, the ratio of dense to loose relative density soil-pile reaction was from 2.0 to 3.0 at a small to large displacement. Direct comparison of the developed p-y curve shows significant differences in the magnitude and shapes with the existing load-transfer curves. Good comparison with the experimental and design studies demonstrates the multidisciplinary applications of the present method.
Parametric Study of Pile Group Subjected to Lateral Load Using ‘P–Y’Analysis
The analysis of laterally loaded piles is a complex soil structure interaction problem. Flexural stresses developed due to combined action of axial load and bending moments must be evaluated in a realistic and rational manner for the safe and economical design of pile foundation. Though most of the analyses consider the behaviour of soil as linear, in actual practice it behaves in the non-linear fashion. In the present paper the parametric study of the pile group subjected to lateral load is reported. The pile is idealized as one dimensional beam element, pile cap as two dimensional plate element and the soil as non-linear springs using the p-y curve developed by Georgiadis et al. (1992). Non-linear response of the system is compared with the linear response of the system.
Development of p-y Curve Model for Sand Using Finite Element Analysis of Laterally Loaded Piles
Research Square (Research Square), 2022
In this study, a 3-D finite element (FE) analysis was used for estimating the lateral capacity of piles driven in sand soils. The effects of different properties of the sand on the p-y curves were studied. Using the results of FE analysis, a model for predicting p-y curves for sandy soils was developed based on the pile shape, which is a combination of tangent hyperbolic and power functions. The results of the developed model were used to demonstrate its applicability in obtaining the p-y curves for the piles driven in sand soils having increase in modulus of elasticity with depth, in sand layers with different modulus of elasticity and unit weight, and at different overburden pressures. The results of the developed model were compared to the results of full-scale pile load test that was conducted at Mustang Island, which demonstrates the ability of the model for predicting the p-y curves and lateral behavior of piles in sandy soils with good accuracy. The results of this study showed that there is little reliability on the results obtained from Reese model, which is the most common method for obtaining lateral behavior of the piles. To consider uncertainties in soil properties due to pile installation, ranges of 0.5 to 1.0 and 1.0 to 2.0 for the value of K in the developed model were proposed for non-displacement and displacement piles, respectively.
Geotechnical and Geological Engineering, 2007
Lateral load-deflection behaviour of single piles is often analysed in practice on the basis of methods of load-transfer P–Y curves. The paper is aimed at presenting the results of the interpretation of five full-scale horizontal loading tests of single instrumented piles in two sandy soils, in order to define the parameters of P–Y curves, namely the initial lateral reaction modulus and the lateral soil resistance, in correlation with the pressuremeter test parameters. P–Y curve parameters were found varying as a power of lateral pile/soil stiffness, on the basis of which hyperbolic P–Y curves in sand were proposed. The predictive capabilities of the proposed P–Y curves were assessed by predicting the soil/pile response in full-scale tests as well as in centrifuge tests and a very good agreement was found between the computed deflections and bending moments, and the measured ones. Small-sized database of full-scale pile loading tests in sand was built and a comparative study of some commonly used P–Y curve methods was undertaken. Moreover, it was shown that the load-deflection curves of these test piles may be normalised in a practical form for an approximate evaluation of pile deflection in a preliminary stage of pile design. At last, a parametric study undertaken on the basis of the proposed P–Y curves showed the significant influence of the lateral pile/soil stiffness on the non-linear load-deflection response.
The Response of Py Curve of Soil-Pile Characterized by the Design Parameters in Liquefiable Sand
2018
This paper proposed the establishing procedure and introduced an OpenSessPL for investigating dynamic p-y curves in liquefying ground based on the simulated shaking table tests for pile-soil-bridge structure were conducted successfully corresponding to liquefying ground covered with clay layer simulated as a middle circumference of three layers adopting reinforced concrete single pile-pier exposed by a series of sinusoidal and EI centro earthquake events wave of different amplitudes and frequencies. A series of numerical simulations based on the established 3D finite element analysis method was carried out by including earthquake events to investigate the deveplod of p-y curves due to the effect of design parameters such as; pile stiffness, the internal angle of sand and the depth of pile insertion. The mentioned parameters beside seismic motion shape, peak acceleration (g) and degree of ground inclination have a certain theoretical and practical significance for seismic design rela...
Analytical investigation of pile–soil interaction in sand under axial and lateral loads
International Journal of Advanced Structural Engineering, 2014
This paper presents a numerical study of pilesoil interaction due to application of axial and lateral loads to piles in sand. The pile-soil interaction was analyzed using the finite difference (FD) software LPILE and two finite element (FE) software. The three-dimensional (3D) FE models of pile-soil interaction have been created using Abaqus/Cae and SAP2000. Various types of soft soil were studied, such as loose, medium, and dense sand. A lateral displacement of 2 cm was applied to the top of the pile while maintaining a zero slope in a guided fixation. A combined lateral and axial load of 300 kN was also studied. The paper compared between the bending moments and lateral displacements along the depth of the pile obtained from the FD solutions and FE analyses. A parametric study was conducted to study the effect of crucial design parameters such as the modulus of elasticity of soil and the number of nonlinear soil springs that can be used to model the soil. A good agreement between the results obtained by the FE models and the FD solution was observed. Also, the FE models were capable of predicting the pile-soil interaction for all types of soft soil.
STATIC AND DYNAMIC BEHAVIOR OF LATERALLY LOADED SINGLE PILES AND DETERMINATION OF P-Y CURVES
2013
"To improve the understanding of soil-pile interaction under horizontal dynamic loads and seismic events, a parametric centrifugal study was undertaken. Flexible piles with pile caps of different masses and instrumented with 20 strain gauges on the length of the pile were used for this purpose. The piles were impacted and the resulting displacement and acceleration for different levels of force were measured. The equation of the movement of a beam equivalent to the pile under dynamic loading has been established and all the terms of this equation was determined using the experimental results. The term of inertia was divided into two parts, one related to the mass of the pile and the other related to the mass of the associated soil. The contribution of each term to the equation at different period (or time of) of vibration was illustrated. Distribution versus time of the displacements and the reactions of the soil at any depth were deduced from the profiles of the bending moments by a double integration and a double derivation respectively. Then the dynamic P-y curves or loops were constructed based on these results. The procedures of experimental tests and P-y curves construction are explained and a comparison between static and dynamic P-y curves is also indicated."
P-y Curves of 2x2 pile group in liquefiable soil under dynamic loadings
Arabian Journal of Geosciences, 2020
The seismic analysis of pile groups subjected to lateral and axial loads is often implemented separately. As a result, the calculated bending moment and deflection are found to be nonrealistic in nature, as compared with conditions where a combined analysis is carried out. In reality combined loadings are encountered in almost all situations and the occurrence of pure loadings (either lateral or vertical) is either nonexistent or scarce. In the present study, the numerical analysis of a 2 × 2 pile group under the action of combined loadings (lateral load, vertical load, and seismic ground motions) and embedded in a layered soil is carried out using the FLAC3D computer program. The liquefiable soil layer is modeled using the Mohr-Coulomb with Byrne constitutive model, while the non-liquefiable soil layers are modeled with the conventional Mohr-Coulomb constitutive model. The pile group is considered an elastic model. The proposed numerical model is validated with the existing dynamic centrifuge test results and good agreement between the results is observed. Finally the dynamic P-y (P denotes the lateral load applied at the pile cap and y is the lateral pile group deflection at the pile head) curves are generated for different combinations of vertical load, lateral load, and input seismic ground motions in liquefiable and non-liquefiable soil. It is observed that for a constant vertical load (V) having a magnitude equal to 0.50 times the ultimate pile load capacity (0.50V ult), the pile group deflection increases by 36% when the lateral load increases from 300 to 900 kN, while the increase is by 48.5% for V = V ult and for the same increase in the lateral load. Similarly 2001 Bhuj and 2011 Sikkim motions caused an amplification of deflection by 8.4 and 9 times, respectively. The influence of vertical loads increases the pile head displacement and should be considered for determining the dynamic P-y curves. The proposed dynamic P-y curves will be beneficial to geotechnical engineers for understanding the qualitative response of pile groups under combined loading conditions.