Influencing Factors of Bearing Behavior of Settlement Reducing Pile Foundation for Immersed Tunnel

Abstract:

Settlement reducing pile foundation has recently been proposed as an important progress in the design theory of pile foundation, which is one type of deformation-based foundations. Compared with the common design method, settlement reducing pile foundation can greatly reduce the number of required piles. Aimed to the influence of pile cap, cushion, pile spacing, pile length on bearing behavior of settlement reducing pile foundation, the indoor tests on steel pipe settlement reducing pile foundation for immersed tunnel were carried out in sand. Based on uniform design, the six groups of tests with 3×4 pile groups were conducted, furthermore, earth pressure, axial force of pile shaft, and foundation settlement were measured. When the load applied increased, the plastic failure of the soil occurred under the corner of immersed tunnel. The result shows that the earth pressure distribution against immersed tunnel is similar to the normal base reaction in sand which is big in the center and small in the border. The correlation analysis result indicates that apply pile cap, reduce cushion thickness, increase pile spacing and increase pile length can increase the pile load sharing ratio. Compared with the average value of correlation coefficient of each influencing factor, pile length has the most remarkable effect on the pile load sharing ratio, then cushion and pile cap, and pile spacing has the minimal effect among these influencing factors. The research can provide a reference for design of relevant projects.

• Periodical: Applied Mechanics and Materials (Volumes 353-356)
• Pages: 779-784
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.353-356.779
• Online since: August 2013
• Authors: Xiao Hui Huang, Wei Ming Gong, Ting Huang, Ri Cheng Xie, Guo Ping Xu
• Keywords: Immersed Tunnel, Model Test, Pile Load Sharing Ratio, Settlement Reducing Pile, Uniform Design

References

[1] Run Liu, Shuwang Yan, The mechanism of settlement reducing pile foundation with bedding layers and in site experiment, Journal of Building Structures. 21 (2000) 76-81. (In Chinese).

[2] J. B. Burland, B. B. Broms, V. F. De Mello, Behavior of foundations and structures, Proc. 9th Int. Conf. on Soil Mechanics and Foundation Engineering, Tokyo, 1977, Vol. 2, pp.495-546.

[3] M. F. Randolph, Design methods for pile groups and piled rafts, Proc. 13th Int. Conf. on Soil Mechanics and Foundation Engineering, New Delhi, 1994, Vol. 5, pp.61-82.

[4] H. G. Poulos, E. H. Davis, Pile foundation analysis and design, John Wiley&sons Inc., New York, (1980).

[5] Ning Li, Xuan Han, Study on mechanism of cushion in composite pile foundation, China Civil Engineering Journal, 34 (2001) 68-73. (In Chinese).

[6] Yuejun Chi, Erxiang Song, Huai Jin, Wenxin Gao, Experimental study on stress distribution of composite foundation with rigid piles, Rock and Soil Mechanics, 24 (2003) 339-343. (In Chinese).

[7] Mostafa El Sawwaf, Experimental study of eccentrically loaded raft with connected and unconnected short piles, J. Geotech. Geoenviron. Eng., 136 (2010) 1394-1402.

DOI: 10.1061/(asce)gt.1943-5606.0000341

[8] Kaitai Fang, Uniform design and uniform design table, Science Press. Beijing, 1994. (In Chinese).