Effect of Deep Remediation and Improvement on Bearing Capacity and Settlement of Piled Raft Foundation Subjected to Static and Cyclic Vertical Loading

2021 ◽  
pp. 1-11
Author(s):  
Mahdi O. Karkush ◽  
Mahmoud S. AbdulKareem ◽  
Hadeel Dekhn
Keyword(s):  
Bearing Capacity ◽  
Vertical Loading ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation

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.

Working Mechanism of Two-Phase Varying Stiffness Piled Raft Foundation

2014 ◽  
Vol 590 ◽  
pp. 326-330
Author(s):  
Yuan Huang ◽  
Xin Jian Feng ◽  
Jian Lin Zhang ◽  
Shu Zhi Lin
Keyword(s):  
Bearing Capacity ◽  
Working Mechanism ◽  
Two Phase ◽  
Foundation Soil ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Tip Resistance ◽  
Working Principle ◽  
Side Friction

In this paper, the FEM software ABAQUS is used to analysis the pile-soil load share ratios, load share value of pile side friction and tip resistance for three bases, including natural raft foundation, conventional piled raft foundation and two-phase varying stiffness piled raft foundation. Furthermore, the deformation and settlement of deformation-coordinating device are studied as well. Based on the research of the working characteristic of piles and soil, it highlights the good working mechanism of two-phase varying stiffness piled raft foundation. The analysis results show that two-phase varying stiffness piled raft foundation, with obvious two phase stress characteristics, has a working principle between natural raft foundation and conventional piled raft foundation, fully making use of the bearing capacity of foundation soil, effectively improving the joint bearing capacity of piles and soil.

Application Study of Long-Short-Piled Raft Foundation

2012 ◽  
Vol 170-173 ◽  
pp. 242-245
Author(s):  
Xin Yu Xie ◽  
Ming Xin Shou ◽  
Jie Qing Huang ◽  
Kai Fu Liu
Keyword(s):  
Bearing Capacity ◽  
Pile Foundation ◽  
National Standard ◽  
Application Study ◽  
Existing Building ◽  
Piled Raft ◽  
Piled Raft Foundation ◽  
Raft Foundation ◽  
Total Settlement ◽  
Reinforcement Design

The long-short-piled raft foundation is an unusual type of building base. This kind of foundation is usually applied for pile foundation reinforcement of existing buildings when shortage of bearing capacity of piles occurs. The bearing capacity of pile foundation is improved and less settlement is expected. Since this method has so many obvious advantages, it is recommended in the reinforcement design of piled raft foundation of an existing building in Tianjin. Longer reinforced concrete bored piles are adopted as the supplementary ones. The bearing capacity of this kind of piled raft foundation was studied. The settlement was also analyzed with the National standard method together with the finite element numerical method. According to the study, the bearing capacity of piled raft foundation is enhanced effectively after adding piles. Also, the results show that the total settlement and differential settlement during the construction is in control respectively.

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