Comparative Analysis of Axial Load Capacity for Piled-Raft Foundation with Changes in Groundwater Level

The introduction of Eurocode in Kazakhstan allows for the application of modern technological innovations and the elimination of technical barriers for the realization of international projects. It is significant to study the international standards and design requirements provided in Eurocode. This study presents a comparative analysis of Kazakhstani and European approaches for the geotechnical design of foundations and provides the design methods in the considered codes of practice. Three different types of foundations (i.e., raft, pile, and piled raft foundations) were designed following SP RK 5.01-102-2013—Foundations of buildings and structures, SP RK 5.01-103-2013—Pile foundations, and Eurocode 7: Geotechnical design for the Nur-Sultan soil profile. For all three types of foundations, the calculated results of bearing resistance and elastic settlement showed the conservativeness of Eurocode over SNiP-based Kazakhstani building regulations, as the values of bearing resistance and elastic settlement adhering to Kazakhstani code exceeded the Eurocode values. The difference between the obtained results can be explained by the application of higher values of partial safety factors by Eurocode 7. Sensitivity analysis of the bearing resistance on foundation parameters (i.e., raft foundation width and pile length) for the Kazakhstani and European approaches was performed to support the conclusions of the study.

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ANALYSIS FOR AXIAL LOAD DISTRIBUTION IN PILE IN A PILED RAFT FOUNDATION STIFF CLAY BY FINITE ELEMENT

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v5.i3.2017.1768 ◽

2017 ◽

Vol 5 (3) ◽

pp. 193-197

Author(s):

Sanjeev Gill ◽

Seema Rani

Keyword(s):

Finite Element ◽

Load Distribution ◽

Axial Load ◽

Three Dimensional ◽

Nonlinear Finite Element ◽

Nonlinear Finite Element Method ◽

Piled Raft ◽

Piled Raft Foundation ◽

Raft Foundation ◽

Stiff Clay

In this paper piled raft foundation has been analysed by nonlinear finite element method. The three dimensional nonlinear finite element analyses predict the actual behaviour of axial load distribution. The axial load variation is nonlinear for all the piles. For all pressure the element stress is more than the element stress. For any pressure the nodal deflection is maximum at top and minimum at bottom. Up to certain height the element stress is almost zero for all pressures. After that height the element stress increases with increase in height. The element stress increases with increase in pressure the measurement of axial load distribution in pile in field is very difficult and costly.

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Behaviour of Vertically Loaded Piled Raft System

Journal of Computational and Theoretical Nanoscience ◽

10.1166/jctn.2020.8900 ◽

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.

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Issues on Design of Piled Raft Foundation

JOURNAL OF ADVANCES IN CHEMISTRY ◽

10.24297/jac.v14i1.5905 ◽

2018 ◽

Vol 14 (1) ◽

pp. 6057-6061 ◽

Cited By ~ 1

Author(s):

Padmanaban M S ◽

J Sreerambabu

Keyword(s):

Contact Area ◽

Concrete Slab ◽

Design Procedure ◽

Bending Moment ◽

Foundation Design ◽

Detailed Review ◽

Piled Raft ◽

Piled Raft Foundation ◽

Raft Foundation ◽

Influencing Parameters

A piled raft foundation consists of a thick concrete slab reinforced with steel which covers the entire contact area of the structure, in which the raft is supported by a group of piles or a number of individual piles. Bending moment on raft, differential and average settlement, pile and raft geometries are the influencing parameters of the piled raft foundation system. In this paper, a detailed review has been carried out on the issues on the raft foundation design. Also, the existing design procedure was explained.

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