scholarly journals Numerical analysis of XCC pile group effect and bearing capacity of piled raft foundation

2020 ◽  
Vol 768 ◽  
pp. 032015
Author(s):  
Qi Wu ◽  
Lai Xu
Keyword(s):  
Numerical Analysis ◽  
Bearing Capacity ◽  
Pile Group ◽  
Group Effect ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Pile Group Effect

Analysis of Vertical Bearing Capacity of Single-Row Pile Group of an Offshore Platform

2012 ◽  
Vol 188 ◽  
pp. 54-59
Author(s):  
Rui Hua Zhuo ◽  
Run Liu ◽  
Xin Li Wu ◽  
Yang Yang Zhao
Keyword(s):  
Bearing Capacity ◽  
Pile Group ◽  
Normal Operation ◽  
Deep Penetration ◽  
Group Model ◽  
Group Effect ◽  
Design Code ◽  
Vertical Bearing ◽  
Pile Group Effect ◽  
Vertical Bearing Capacity

The vertical bearing capacity of a special pile group of platform in an offshore gas field has been studied. Large diameter d (2.134 m), deep penetration l (96 m), small spacing sa (3.507 m), and only one row piles are the usual characteristics of the pile group foundation in offshore engineering. According to the requirements of the related design code, the super pile group effect has to be considered. However, with the usual design code, when sa/d, the ratio of spacing to diameter, is less than 2.0, there is no way to consider the pile group effect. In this paper, considering the occlusion effect of soil plug of pipe pile, several methods have been introduced to study the super pile group effect of the vertical bearing capacity. These methods include linear elastic theory method, the method recommended by the Code of Pile Foundation in Port Engineering (JTJ254-98), and the method with virtue of the existing pile group model test results. Meanwhile, the plugged and unplugged conditions have been considered, respectively. Through the analysis, the factors of safety in extreme and normal operation states are obtained, and the results satisfy the design specifications.

Interaction effects on load-carrying behavior of piled rafts embedded in clay from centrifuge tests

2015 ◽  
Vol 52 (10) ◽  
pp. 1550-1561 ◽  
Author(s):  
Donggyu Park ◽  
Junhwan Lee
Keyword(s):  
Pile Group ◽  
Interaction Effects ◽  
Group Effect ◽  
Piled Raft ◽  
Centrifuge Tests ◽  
Interaction Factor ◽  
Load Carrying ◽  
Lower Load ◽  
Load Tests ◽  
Pile Group Effect

In the present study, various interaction effects and load-carrying behavior of piled rafts embedded in clay were investigated. For this purpose, a series of centrifuge load tests were conducted using different types of model foundations, including single pile, group piles, piled raft, and unpiled raft. Different clay conditions were considered to prepare for centrifuge specimens. It was found that the pile group effect in clays is significant within initial loading range, showing lower load-carrying capacity. As settlement increases, the pile group effect becomes less pronounced. For both soft and stiff conditions, the values of the raft-to-pile (R-P) interaction factor varied initially, which became converged to some values around unity with increasing settlement. Similar tendency was observed for the pile-to-raft (P-R) interaction factor. The load responses of different pile components within the piled raft were not significantly different for the soft condition. For the stiff condition, the corner and inner piles showed the highest and lowest load-carrying capacities, respectively, due to piled-raft interaction effects. Correlations to cone resistance were analyzed and presented for the base and shaft resistances of piles for piled rafts.

Behaviour of Vertically Loaded Piled Raft System

2020 ◽  
Vol 17 (5) ◽  
pp. 2383-2387
Author(s):  
K. Merin Jose ◽  
Divya Krishnan ◽  
P. T. Ravichandran
Keyword(s):  
Bearing Capacity ◽  
Load Capacity ◽  
Load Test ◽  
Ultimate Load Capacity ◽  
Foundation Soil ◽  
Total Load ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Dense State

A foundation gives the overall strength to a building by providing a level surface for the building to stand and distributing the total load uniformly to the underlying soil. The type of foundation to be chosen varies with the foundation soil and site conditions. Piled raft system are a type of foundation preferred when the bearing strata has less soil bearing capacity and a huge load has to be transferred. Thus Piled raft foundation is a foundation system which uses the combined effects of both rafts and piles such that it is expected to transfer huge loads without large settlement. An ample evaluation of factors like number of piles, length of piles, and degree of compaction of soil that affects the performance of the foundation is required, to understand the concept of piled raft foundation. This study was based on the behaviour of vertically loaded piled raft system by varying the length of pile as 100 mm, 150 mm and 200 mm with 4 and 9 numbers of pile conducted on loose and dense state in cohesion less soil. A vertical load test was conducted on unpiled raft both in loose and dense state of soil also and the results obtained from both piled and unpiled rafts were compared together. The compared results indicated an improvement in ultimate load capacity and settlement reduction. A settlement reduction of 32.71% and increased bearing capacity of 63.67% were observed when compared to unpiled raft under dense condition. About 84% of increase in bearing capacity of the piled raft system was observed with varying the degree of compaction of soil from loose to dense state of soil. An optimum design of this piled raft foundation can provide an alternative foundation for high rise buildings, transmission towers, bridges etc. and it can provide an aid to the threat of differential settlement for heavy loaded buildings in poor bearing strata.

scholarly journals A simplified algorithm for the design of piled raft foundations applied for the case study of a building erected within Żoliborz-Szczęśliwice glacial tunnel valley

2015 ◽  
Vol 47 (2) ◽  
pp. 113-126
Author(s):  
Grzegorz Kacprzak ◽  
Katarzyna Mazurek ◽  
Tomasz Daktera
Keyword(s):  
Bearing Capacity ◽  
Design Method ◽  
Residential Building ◽  
Organic Soil ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Geological Conditions ◽  
Vertical Displacements ◽  
Simplified Algorithm

Abstract A common engineering solution for excessive settlement with raft foundation (s) is the use of piles in order to reduce the vertical displacements, in this method, the whole structural load is transferred to the piles. This is an overly cautious approach, and there remains a need to find an optimal design method for a building’s foundations. Such a solution may be the piled raft foundation, which allows a reduction of the number of piles due to the integration of the raft in the bearing capacity of the foundation. The aim of the article is to estimate the contribution of foundation elements such as the raft and the piles in the bearing capacity of a residential building located in Warsaw, where the geological conditions are characterized by organic soil layers, principally of gyttja.

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