Modeling the Response of a Piled-Raft Footing: Ultimate Bearing Capacity
- PDF / 1,525,232 Bytes
- 13 Pages / 595.276 x 790.866 pts Page_size
- 88 Downloads / 222 Views
RESEARCH PAPER
Modeling the Response of a Piled‑Raft Footing: Ultimate Bearing Capacity Harvinder Singh1 · Prashant Garg1 · J. N. Jha2 Received: 22 October 2018 / Accepted: 25 October 2020 © Shiraz University 2020
Abstract The design of pile–raft foundation is a complex problem due to pile-to-pile, pile-to-soil, pile-to-raft and raft-to-soil interaction effect; hence, a simplified and standard procedure could not be evolved so far; in spite of the fact that this type of footing finds versatile applications in the field and its use as a foundation system helps to transfer a heavy load satisfactorily and that comes with a reduced settlement, and thus, it offers an economical design without compromising the safety of the structure. The present paper presents an analytical model to predict the ultimate bearing capacity of piled-raft footings. The study has been derived using an extensive set of experimental data obtained from the studies carried out in the laboratory. Finally, the response of a full-sized raft footing, designed using the proposed model, was simulated on PLAXIS-3D for the validation purpose. The results from the model are in good agreement with the values obtained during the simulation study carried out on the PLAXIS-3D. Sensitivity analysis carried out with a soil stratum of loose and dense sand indicates that there is a significant effect of the soil properties on the load-carrying capacity of the piled-raft footing. Accordingly, a relationship is proposed to take into account the effect of the sand relative density during the analysis. Keywords Pile Raft · Analytical Modeling · Statistical Modeling · Experimental setups · BCR · Pile aspect ratio
1 Introduction The piled-raft foundation system finds a wide range of applications in transferring the superstructure load to underlying soils. Its use is more widespread in cases where the bearing capacity of the soil is low or the soil exhibits high settlement upon loading. The past investigations (Poulos and Davis 1980; Cooke 1986; Cunha et al. 2001; Poulos 2001a, b; Maharaj 2003; Horikoshi et al. 2003; Bourgeois et al. 2012; Nguyen et al. 2014) have revealed that the use of the piled-raft as a foundation system helps to transfer a heavy loading satisfactorily and that comes with a reduced settlement, and thus it results in an economical design without compromising the safety of the structure. A large number of factors have been found to control the response of the piledraft foundation system, such as the plan dimensions of the
* Harvinder Singh [email protected]; [email protected] 1
Civil Engineering Department, Guru Nanak Dev Engineering College, Ludhiana, Punjab, India
MIT Muzaffarpur, Muzaffarpur, Bihar, India
2
raft, the length and diameter of the piles, and their centerto-center spacing, and distribution of the piles in the group. Because of so many factors, the system is highly redundant in nature. It is an established fact that the piled-raft foundation system exhibits an entirely different response upon loading in comparison with iso
Data Loading...
