Abstract
The combined raft, soil and pile foundation system has reached a high level of familiarity and is now being used to support a large number of structures. When the bearing capacity of the raft foundation is acceptable but the settlement value exceeds the permissible limit, raft-soil system is reinforced with piles to reduce settlement. Here, piles act as settlement reducers to the raft-soil foundation system. Different researchers have studied the effect of varying pile, raft and soil parameters on the settlement response and load-sharing behaviour of the raft and piles in a combined raft, soil and pile foundation system but less attention has been paid to the stress response behaviour of the raft. As this aspect is considered to be important from economics of raft design, a study has been performed to understand the stress response of the raft on the introduction of piles. The stress response of the raft for varying load conditions, Ec/Es ratios, thicknesses of raft and diameters of pile have been studied by performing numerical analyses on the foundation system supporting a moderately loaded 12-storeyed real-time commercial structure located in Chennai, India. An attempt has been made to study the applicability of Equivalent Pier concept. The above analyses were performed for two different layouts of piles. The behaviour of the stress and settlement responses of the raft reinforced with piles was compared with unpiled raft. Staad-Pro V8i and Ansys 16.0 have been used for the study and this paper presents observations and discussions from the study.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Similar content being viewed by others
References
Balakumar V (2008) Experimental studies of model piled raft on sand and field study of proto type behaviour. Doctoral dissertation, PhD thesis, Anna University, Chennai
Balakumar V, Huang M, Oh E, Balasubramaniam AS (2013a) Equivalent pier theory for piled raft design. In: Proceedings of the 18th international conference on soil mechanics and geotechnical engineering
Balakumar V, Huang M, Oh E, Balasubramaniam AS (2013b) A design method for piled raft foundations. In: Proceedings of the 18th international conference on soil mechanics and geotechnical engineering, Paris, pp 2671–2674
Cooke RW (1986) Piled raft foundation on stiff clays—a contribution to design philosophy. Geotechnique 36(2):169–203
Fran E (1991) In: Measurements beneath piled rafts. Keynote lecture. ENPC conference Paris, pp 1–21
Poulos HG (2001) Piled raft foundations: design and applications. Geotechnique 51(2):95–113
Poulos HG (1994a) Alternative design strategies for piled raft foundations. In: Proceedings of the 3rd international conference deep foundations, Singapore, pp 239–244
Poulos HG (1994b) An approximate numerical analysis of pile–raft interaction. Int J Numer Anal Methods Geomech 18(2):73–92
Poulos HG (1998) The pile-enhanced raft-an economical foundation system. In: Proceedings, XI Brazilian conference on soil mechanics and geotechnical engineering, BrasÃlia, vol 4, pp 27–43
Zeevaert L (1957) Compensated friction pile foundation to reduce the settlement of buildings on highly compressible volcanic clay of Mexico city’, In: Proceedings of the 14th international conference on soil mechanics and foundation engineerin, London (1957)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2020 Springer Nature Singapore Pte Ltd.
About this paper
Cite this paper
Malavika, L.M., Balakumar, V., Chandrasekaran, S.S. (2020). Effect of Piles on the Design of Raft Foundation. In: Latha Gali, M., Raghuveer Rao, P. (eds) Construction in Geotechnical Engineering. Lecture Notes in Civil Engineering, vol 84. Springer, Singapore. https://doi.org/10.1007/978-981-15-6090-3_5
Download citation
DOI: https://doi.org/10.1007/978-981-15-6090-3_5
Published:
Publisher Name: Springer, Singapore
Print ISBN: 978-981-15-6089-7
Online ISBN: 978-981-15-6090-3
eBook Packages: EngineeringEngineering (R0)