DYNAMIC ANALYSIS AND COMPARATIVE STUDY OF THREE PILES AND FOUR PILES (original) (raw)

PILE RESPONSE DURING EARTHQUAKE AND PERFORMANCE EVALUATION OF PILE FOUNDATION

Pile foundation response during earthquakes is strongly affected by nonlinear soil-pile foundation interaction. The damages to pile foundations during the Hyogo-ken Nanbu earthquake of 1995 were obviously attributed to nonlinear interaction of soil-pile foundation-superstructure. Dynamic centrifuge tests are performed on a four-pile group foundation model embedded in saturated fine sand layers. The pile foundation model is excited by a shaking table at the pile tip and by lateral loading at the pile head to investigate the effect of inertia force and soil displacement, respectively, on pile bending moments. The inertial and kinematic pile bending moments are compared with analytical results. Next, earthquake response analyses are conducted to clarify the effect of the nonlinear soil-pile foundation-superstructure system on performance of pile foundation. Pile bending moments are calculated using the nonlinear relationship between bending moment and curvature dependent on axial force. Performance evaluation of the pile foundation is discussed on the basis of pile curvature and pile foundation deformation.

Dynamic Analysis to Study Soil-Pile Interaction Effects

The prediction of the behavior of the pile foundations is of paramount importance in the seismic design and assessment piles for the structural sustainability during earthquake. Generally pile provides a good agreeable performance in the complex soils conditions like soft soils having less bearing capacity. The nonlinear condition and dynamic condition are coupled with each other to produce the complex soil action to the pile motion which can be well captured by the soil structure interaction phenomenon stated as soil-pile interaction analysis. In this research paper numerical analysis of a single pile is carried out for a different soil conditions like, C-soils, Ø-Soils and C-Ø soils to understand the soil-pile interaction for a EL-Centro (1940) ground motion. The displacements profiles are studied for flexible long and rigid short pile for the different soil types as mentioned earlier and soil pile interaction analysis. The axi-symmetric numerical model is developed by using Finite Element Program Open-Sees PL 18 to understand the soil pile interaction under the dynamic loading condition. The study concludes that the maximum displacement is less for C-Ø soil as compared to other two types C-soil and Ø -soil. Under the dynamic loading conditions, long pile is more sustainable than the Short rigid pile.

Influence of the pile toe condition on the dynamic response of a group of pile foundations

International Journal of Advanced Structural Engineering

The anchorage of the piles on a stiffer soil layer plays an important role to transmit the loads of the superstructure to the soil. Depending on the pile toe condition, three configurations of piles are considered: floating piles, rested, and anchored piles. To study the effect of the pile toe condition on the dynamic response of pile and pile groups, a three-dimensional finite element modeling of the soil-pile-slab dynamic interaction is presented. The soil and piles are represented as continuum solids and the slab by structural elements. Quiet boundaries are placed at the boundaries of the model to avoid wave reflection. The formulation is based on the substructuring method. The dynamic response is obtained in terms of the dynamic impedances. In this study the dynamic response of the floating, rested, and anchored piles are analyzed and the group effect is shown. An analysis of the horizontal and vertical pile foundation impedances is presented and the results are compared with different configurations.

Dynamic Analysis of Pile Foundation with Footing in Different Foundation Soils

Several studies have done to obtain storey displacement to recognize the structural safety in various loading conditions. The types of soil, types of foundation and building frame form a complete structural system to resist the external loads. In earthquake prone areas the extensive damage is caused due to the failure of foundation (sub structure) that leads to the displacement of structure which causes loss of human life and economy. Types of foundations, footings and foundation soils have greater impact on stability and design criteria of structure. In this research, an attempt has been made to find the effect of deep foundation (single under-reamed friction pile) with or without square footing on the displacement behavior of a four storied, one bay frame resting on different types of soil under dynamic loading using the finite element analysis software ANSYS WORKBENCH (18.0). It is well known that the foundation failures during earthquake excitation are greatly influenced by the ...

Analysis and Design of Piles for Dynamic Loading

With the acceptance of Eurocode 8 in Hungary a new level of seismic design is now necessary. This paper outlines some of the past history and present implementation of foundation design for seismic loading as practiced in Hungary. It shortly describes the possibilities of modeling foundations (fix support, linear elastic support, non-linear elastic support) during the design of the superstructure, and introduces the Hungarian practice. The influence of the different support's methods for the bearing forces/stresses of a superstructure is analyzed on a typical reinforced concrete office building using SAP2000 finite element software. The results of the calculation are compared through the moment of a column, the deflection and the support reaction.

A Review: Earthquake Analysis of Pile Group with Different Variations in Dimensions & Parameters

international journal for research in applied science and engineering technology ijraset, 2020

As per demand of current construction many project are running such as metro construction, bridges, tall building, industries, etc. In such type of construction where the soil bearing capacity (SBC) is very low it is necessary to provide pile foundation. Dynamic analysis is also necessary to be carried out for different pile group for earthquake. The stress resting action increases with the group action of piles. The paper studies about pile group, modelling of four piles and eight pile groups are done taking space between them as 2.5D and 3D, where D is the dia. of the pile. Diameter of four pile group is 0.6 &diameter of eight pile group is 0.4, shape chosen to arrange the pile group are Rectangle, Square, Diamond and Staggered .The analysis of different shape pile groups will be done using the response spectrum method based using STAAD Pro. Parameters such as displacement, shear force (SF) and bending moment (BM) are taken in consideration for pile group analysis. Pile cap is analyzed for bending moment in 'y' and 'z' direction.

Modelling Study of Pile Group Foundation by Including Lateral Load in Clay Soil

2023

Indonesia's geographical condition causes earthquakes to occur more frequently. This study aims to investigate pile group response under earthquake loading by performing pushover analysis. Since clay soil is dominant and widespread in Indonesia, the study focused on pile group embedded in single layer of clay. The undrained shear strength (Su) parameters of the clay are varied from 20 kPa, to 100 kPa with 20 kPa intervals. The pile and soil were modelled by Beam-on-Nonlinear-Winkler-Foundation (BNWF), and the soil was presented as a series of Winkler springs using the nonlinear p-y method. The analysis was conducted with a finite element method (FEM) software, OpenSees. The pile was modelled as a fiber section, where the transversal and longitudinal reinforcement can be considered. The research found that the soil's Su affects the ductility and formation of plastic hinge. Greater Su resulted in higher ductility and occurrence of plastic hinge. Higher Su was also found to increase the internal force experienced in the pile, as well as lead to higher group efficiency factor. There was no shear failure detected in the results, but bending failure happened at the lead pile in Su 100 kPa. The overturning moment phenomenon occurred on the pile group in Su 20 kPa and 100 kPa. For Su = 20 kPa, this phenomenon is caused by the middle pile and rear pile, which did not have optimal performance. Bending failure at the lead pile led to the phenomenon in Su 100 kPa.

Dynamic behavior of pile foundations under vertical and lateral vibrations

HBRC Journal, 2019

Pile foundations supporting machines, buildings under seismic effect, and wind turbines are subjected to dynamic loads. Under such conditions, there is a necessity to evaluate the dynamic behavior of piles. Therefore, a 3D numerical modeling technique is needed to consider the complicated dynamic interaction between the piles and soil (pile-soil interaction) and between adjacent piles in the same group (pile-soil-pile interaction). To validate the results of 3D numerical simulation of piles, the results obtained from the numerical model has been compared to the measurements of a selected case study. The 3D finite element model has also been used to evaluate the impedance parameters and induced peak displacements. The study is performed for single piles and pile groups. The different techniques to model the piles are evaluated. In addition, the effect of related parameters, such as excitation force frequency (f), soil modulus of elasticity (E s), pile slenderness Ratio (L/D), dimensionless spacing ratio (S/D) and pile group size (n g) have been studied.

ANALYSIS OF PILE FOUNDATION BEHAVIOUR FOR VARIOUS SOIL CONDITION

Pile foundation is used to transfer the ultimate load from the structure to the foundation from soft soil strata to hard soil or rock. FEA model developed to predict the response of pile in static and nonlinear dynamic analysis of pile foundation in layered soil medium based on field data. In the first step static analysis will be performed which were compared and validated with the analytical result. Pile foundation are carried for the various soil condition in order to prove its efficiency in the soil systems. Numerical analysis has been carried out using FEA (NASTRAN) software, which will be used to give load-displacement, stresses and response at pile. 20 node 3D element used to model the pile, biased meshing will be used toward the pile to produce accurate result in the region of interest. These stresses on the pile will be predicted using the finite element method. FE methodology is more precise in predicting the strength of the piles and foundations.

Stability Analysis of Piles Subjected to Lateral Load in Static and Seismic Conditions

Journal of Geological Resource and Engineering, 2013

It is disclosed a method for the stability analysis of foundation piles and piers subjected to lateral loading, both static and seismic conditions. The stability analysis for stratified soil is based upon the models of foundation soil-structure interaction and the Rankine´s theory of earth passive pressure. In addition, its application is simpler and it can be solved using a spreadsheet. The procedure described in this work can be used in homogeneous soils as in stratified soils, considers the horizontal drag forces exerted by the soil mass against the foundation during an earthquake, can be used easily in the four pile and piers boundary cases, and considers the pore pressure generated in a fine saturated soil during an earthquake or during a rapid application of the horizontal load. The solution of two examples are shown, one in static condition and one in seismic condition, detailing the procedure step by step.