Analysis of the effect of pile length in a pile group on the transfer and impedance functions in soil-pile interaction models

2010 ◽  
pp. 445-450 ◽  
Keyword(s):  
Pile Group ◽  
Interaction Models ◽  
Pile Interaction ◽  
Impedance Functions ◽  
Pile Length

scholarly journals REVIEW OF BEARING CAPACITY AND SETTLEMENT OF PILE FOUNDATION IN PORT INFRASTRUCTURE

Pondasi ◽  
2020 ◽  
Vol 23 (2) ◽  
pp. 1
Author(s):  
Adi Sunarno ◽  
Rinda Karlinasari ◽  
Abdul Rochim
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Pile Group ◽  
Standard Penetration Test ◽  
Infrastructure Development ◽  
Lateral Deflection ◽  
Economic Progress ◽  
Port Infrastructure ◽  
Pile Length ◽  
Group Pile

ABSTRACTThe rapid infrastructure development is one of the indicators on the country economic progress. Indonesia as one of the largest archipelagic countries in the world, should be prioritized the port infrastructure to support the maritime. One of the government’s solutions is infrastructure development of Kuala Tanjung port. This research analyzed bearing capacity and settlement of single and group pile foundation on port infrastructure of Kuala Tanjung so it is known that the port is safe to use. The data used are Standard Penetration Test data with soil stratigraphy that is clay and sand. The type of foundation used is Concrete Spun Pile 1000 mm and 600 mm with a pile length of 36 meters. The data are then analyzed by manual calculation and Allpile 6.5E program based on Reese method and methods such as Vesic and Converse-Labarre. The results showed that single pile foundations of 1000 mm and 600 mm each had allowable capacity (Qall) 492.78-538.81 ton and 110.65-128.31 ton, with vertical load (Q) of 330.90 ton, settlement 0.56-1.17 cm and 3.32-3.64 cm, lateral deflection 27.50 cm and 94.90 cm. While the 1000 mm and 600 mm pile group foundations respectively have Qall 8717.31-10796.29 tons and 2059.25-2566.32 tons, with Q of 6618 tons, settlement 0.56-1.68 cm and 3.32-3.64 cm, lateral deflection of 2.49 cm and 19.49 cm. The conclusion of the research indicates that the safe pile foundation used is 1000 mm group pile foundation. Keywords: Bearing Capacity; Foundations; Pile Foundation; Port Infrastructure; Settlement

scholarly journals Numerical modelling of perimeter pile groups in clay

2013 ◽  
Vol 50 (3) ◽  
pp. 250-258 ◽  
Author(s):  
A.V. Rose ◽  
R.N. Taylor ◽  
M.H. El Naggar
Keyword(s):  
Load Distribution ◽  
Load Capacity ◽  
Relative Effectiveness ◽  
Pile Group ◽  
Block Type ◽  
Pile Groups ◽  
Total Load ◽  
Group Behaviour ◽  
Pile Interaction ◽  
Spacing Length

The load distribution among piles in a group varies such that the inner piles often carry a smaller share of the total load compared to the outer piles, which is a result of increased soil–pile interaction. The main objective of this paper is to establish the relative effectiveness of pile groups with no inner piles (perimeter group), when compared to the more common grid configuration. The numerical investigation utilized the finite element programme ABAQUS and considered a range of variables that affect pile group behaviour including number of piles, pile spacing, length/diameter ratio, and soil strength. It was demonstrated that a complete grid group is less efficient than a perimeter group, where efficiency is defined as the load capacity of the whole group expressed as a ratio of the number of piles in the group multiplied by the load capacity of a single isolated pile. Efficiencies close to unity were observed for some perimeter groups. Perimeter groups also showed that a “block” type group failure could occur, where piles were placed at a spacing of less than 2.0 pile diameters,d, centre-to-centre. This often, but not always, led to a reduction in the efficiency of the pile group.

scholarly journals Bearing Characteristics of Composite Pile Group Foundations with Long and Short Piles under Lateral Loading in Loess Areas

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Tianzhong Ma ◽  
Yanpeng Zhu ◽  
Xiaohui Yang ◽  
Yongqiang Ling
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
Horizontal Displacement ◽  
Pile Group ◽  
Lateral Load ◽  
Test Model ◽  
Pile Head ◽  
Load Bearing ◽  
Composite Pile ◽  
Pile Length

It is very necessary to research the bearing characteristics of composite pile group foundations with long and short piles under lateral load in loess areas, because these foundations are used widely. But few people researched this problem in loess areas up to now worldwide. In this paper, firstly, an indoor test model of a composite pile foundation with long and short piles is designed and then employed to explore the vertical load bearing characteristics and load transfer mechanisms of a single pile, a four-pile group, and a nine-pile group under different lateral loads. Secondly, ANSYS software is employed to analyze the load-bearing characteristics of the test model, and for comparison with the experimental results. The results demonstrate the following. (1) The lateral force versus pile head displacement curves of the pile foundation exhibit an obvious steep drop in section, which is a typical feature of piercing damage. A horizontal displacement limit of the pile foundation is 10 mm and 6mm for the ones sensitive to horizontal displacement. (2) The axial force along a pile and frictional resistance do not coincide, due to significant variations and discontinuities in the collapsibility of loess; a pile body exhibits multiple neutral points. Therefore, composite pile groups including both long and short piles could potentially maximize the bearing capacity and reduce pile settlement. (3) The distribution of stress and strain along the pile length is mainly concentrated from the pile head to a depth of about 1/3 of the pile length. If the lateral load is too large, short piles undergo rotation about their longitudinal axis and long piles undergo flexural deformation. Therefore, the lateral bearing capacity mainly relies on the strength of the soil at the interface with the pile or the horizontal displacement of the pile head.

scholarly journals Research on character of screw pile group composite foundation used in high-speed railway

2019 ◽  
Vol 265 ◽  
pp. 05010
Author(s):  
Maocai Zhao ◽  
Lu Zhang
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Pile Group ◽  
Element Model ◽  
Composite Foundation ◽  
Design Parameters ◽  
High Speed Railway ◽  
Screw Pile ◽  
Side Resistance ◽  
Pile Length

As a result of rapid development of a high-speed railway and infrastructure in China in recent years, the subgrade deformation and settlement control standards put forward more stringent requirements. Based on ABAQUS 6.14, established finite element model of screw pile group composite foundation. Then obtained the settlement, axial force distribution and pile side resistance distribution of center pile of pile group. Next design parameters sensitive analysis was made, such as pile length, pile spacing and so on, in order to obtain a reasonable design pile parameters by analysis of mechanical behavior.

Design of reinforcing piles to increase slope stability

1995 ◽  
Vol 32 (5) ◽  
pp. 808-818 ◽  
Author(s):  
Harry G. Poulos
Keyword(s):  
Shear Force ◽  
Soil Mechanics ◽  
Relative Depth ◽  
Soil Movement ◽  
Pile Diameter ◽  
Maximum Shear Force ◽  
Final Design ◽  
Length Step ◽  
Pile Interaction ◽  
Pile Length

This paper describes an approach for the design of piles to reinforce slopes, involving three main steps: (1) evaluating the shear force needed to increase the safety factor to the desired value; (2) evaluating the maximum shear force that each pile can provide to resist sliding of the potentially unstable portion of the slope; and (3) selection of the type and number of piles, and the most suitable location of these piles within the slope. For step 1, stability analyses can be used to assess the required additional shear force for stability. Step 2 involves the use of a computer analysis for the response of a pile to laterally moving soil. This analysis can be implemented via a computer program ERCAP, and enables the resisting shear force developed by the piles to be evaluated as a function of pile diameter and flexibility and the relative depth of the soil movement in relation to the pile length. Step (3) involves the use of engineering judgement in conjunction with the analysis results from steps 1 and 2. The paper describes the ERCAP analysis and the characteristics of pile behaviour it reveals. The application of the approach to a highway bypass problem in Newcastle, Australia, is described in detail. In the final design, a total of 64 bored piles 1.2 m in diameter were used over a total length of slope cutting of about 250 m. The pile lengths ranged between 6 and 12 m, with the spacings varying between 3.2 and 6.0 m. Key words : analysis, boundary element, piles, soil–pile interaction, slope stabilization, soil mechanics.

scholarly journals An Experimental Study on Pile Spacing Effects under Lateral Loading in Sand

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Mahdy Khari ◽  
Khairul Anuar Kassim ◽  
Azlan Adnan
Keyword(s):  
Pile Group ◽  
Experimental Investigations ◽  
Pile Groups ◽  
Dense Sand ◽  
Spacing Effects ◽  
Pile Diameter ◽  
Lateral Resistance ◽  
Model Pile ◽  
Pile Interaction ◽  
Subgrade Modulus

Grouped and single pile behavior differs owing to the impacts of the pile-to-pile interaction. Ultimate lateral resistance and lateral subgrade modulus within a pile group are known as the key parameters in the soil-pile interaction phenomenon. In this study, a series of experimental investigation was carried out on single and group pile subjected to monotonic lateral loadings. Experimental investigations were conducted on twelve model pile groups of configurations 1 × 2, 1 × 3, 2 × 2, 3 × 3, and 3 × 2 for embedded length-to-diameter ratiol/d= 32 into loose and dense sand, spacing from 3 to 6 pile diameter, in parallel and series arrangement. The tests were performed in dry sand from Johor Bahru, Malaysia. To reconstruct the sand samples, the new designed apparatus, Mobile Pluviator, was adopted. The ultimate lateral load is increased 53% in increasing ofs/dfrom 3 to 6 owing to effects of sand relative density. An increasing of the number of piles in-group decreases the group efficiency owing to the increasing of overlapped stress zones and active wedges. A ratio ofs/dmore than6dis large enough to eliminate the pile-to-pile interaction and the group effects. It may be more in the loose sand.

Experimental study of interaction and coupling effects in pile groups subjected to torsion

2008 ◽  
Vol 45 (7) ◽  
pp. 1006-1017 ◽  
Author(s):  
L. G. Kong ◽  
L. M. Zhang
Keyword(s):  
Coupling Effect ◽  
Pile Group ◽  
Test Results ◽  
Pile Groups ◽  
Coupling Effects ◽  
Lateral Resistance ◽  
Torsional Resistance ◽  
Pile Interaction ◽  
Group Configuration ◽  
Centrifuge Model Tests

Piles in a pile group subjected to torsion simultaneously mobilize lateral and torsional resistances. Hence, complicated pile–soil–pile interaction effects and load deformation coupling effects occur in the pile group. In this study, a series of centrifuge model tests were carried out to investigate these effects in three-diameter spaced 1 × 2, 2 × 2, and 3 × 3 pile groups subjected to torsion in both loose and dense sands. The test results showed that the effect of horizontal movement of a pile on lateral behaviors of its adjacent piles is significant in 3 × 3 pile groups and such effect varies with group configuration and pile position. The p-multiplier concept can be used to quantify the effect and values for the p-multiplier are suggested. The effect of lateral movement of a pile on the torsional resistances of its adjacent piles and the effect of torsional movement of a pile on the lateral resistances of its adjacent piles were found to be minor in these tests. For an individual pile in a pile group subjected to torsion, the mobilized lateral resistance was found to substantially increase the torsional resistance of the pile. Such a coupling effect is quantified by a coupling coefficient, β, which describes the contribution of subgrade reaction to the increase of torsional shear resistance.

scholarly journals Serviceability analysis of piled foundations supporting tall structures

2021 ◽  
Author(s):  
Maria Iovino ◽  
Raffaele Di Laora ◽  
Luca de Sanctis
Keyword(s):  
Coupling Effect ◽  
Pile Group ◽  
Mathematical Framework ◽  
Moment Capacity ◽  
Tall Structures ◽  
Pile Interaction ◽  
Elevated Water ◽  
The Moment ◽  
Water Tanks ◽  
Piled Foundations

AbstractPile foundations supporting tall structures, such as wind turbines, chimneys, silos, elevated water tanks or bridge piers, are subjected during their life span to remarkably eccentric loads. These may lead to significant rotations which, however, cannot exceed the limiting values corresponding to the safe operation of the structure. A physically motivated mathematical framework aimed at the prediction of the serviceability performance of such kind of structures is herein presented and discussed. Piles are idealized as uniaxial nonlinear elements characterized by two yielding loads, one in compression and one in uplift, while pile-to-pile interaction effects are modeled by means of superposition, through an approximate solution. The axial load–moment capacity of the pile group is preliminary determined from a recent closed form, exact solution based on upper and lower bound theorems, allowing the analysis to be performed under load control. The model is capable of accounting for the dependence of the moment–rotation response from the dead load of the structure and the ‘coupling effect’ between generalized loads and displacements. The prediction performance of the proposed calculation method is validated against both numerical and experimental benchmarks. Finally, a parametric study allowed to assess the importance of pile-to-pile interaction on the foundation response under eccentric loads.

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