DOI QR코드

DOI QR Code

Effect of slope with overburden layer on the bearing behavior of large-diameter rock-socketed piles

  • Xing, Haofeng (Department of Geotechnical Engineering, Tongji University) ;
  • Zhang, Hao (Department of Geotechnical Engineering, Tongji University) ;
  • Liu, Liangliang (Department of Geotechnical Engineering, Tongji University) ;
  • Luo, Yong (Department of Geology Survey and Design, Guizhou Transportation Planning Survey and Design Academe Co., Ltd.)
  • Received : 2020.01.12
  • Accepted : 2021.02.01
  • Published : 2021.02.25

Abstract

Pile foundation is a typical form of bridge foundation and viaduct, and large-diameter rock-socketed piles are typically adopted in bridges with long span or high piers. To investigate the effect of a mountain slope with a deep overburden layer on the bearing characteristics of large-diameter rock-socketed piles, four centrifuge model tests of single piles on different slopes (0°, 15°, 30° and 45°) were carried out to investigate the effect of slope on the bearing characteristics of piles. In addition, three pile group tests with different slope (0°, 30° and 45°) were also performed to explore the effect of slope on the bearing characteristics of the pile group. The results of the single pile tests indicate that the slope with a deep overburden layer not only accelerates the drag force of the pile with the increasing slope, but also causes the bending moment to move down owing to the increase in the unsymmetrical pressure around the pile. As the slope increases from 0° to 45°, the drag force of the pile is significantly enlarged and the axial force of the pile reduces to beyond 12%. The position of the maximum bending moment of the pile shifts downward, while the magnitude becomes larger. Meanwhile, the slope results in the reduction in the shaft resistance of the pile, and the maximum value at the front side of the pile is 3.98% less than at its rear side at a 45° slope. The load-sharing ratio of the tip resistance of the pile is increased from 5.49% to 12.02%. The results of the pile group tests show that the increase in the slope enhances the uneven distribution of the pile top reaction and yields a larger bending moment and different settlements on the pile cap, which might cause safety issues to bridge structures.

Keywords

References

  1. Armaghani, D.J., Faradonbeh, R.S., Rezaei, H., Rashid, A.S.A. and Amnieh, H.B. (2018), "Settlement prediction of the rock-socketed piles through a new technique based on gene expression programming", Neural Comput. Appl., 29(11), 1115-1125. https://doi.org/10.1007/s00521-016-2618-8.
  2. Armaghani, D.J., Shoes, R.S.N.S.B.R., Faizi, K. and Rashid, A.S.A. (2017), "Developing a hybrid PSO-ANN model for estimating the ultimate bearing capacity of rock-socketed piles", Neural Comput. Appl. 28(2), 391-405. https://doi.org/10.1007/s00521-015-2072-z.
  3. Chen, X.Y., Zhang, M.Y. and Bai, X.Y. (2019), "Axial resistance of bored piles socketed into soft rock", KSCE J. Civ. Eng., 23(1), 46-55. https://doi.org/10.1007/s12205-018-0942-5.
  4. Gao, R., Zeng, Y.J. and Zhu, B. (2011), "Centrifuge model testing on super-long rock-socketed bored piles under vertical loading", Geomech. Geoeng., 6(1), 21-29. https://doi.org/10.1080/17486025.2010.521590.
  5. Dai, G.L., Salgado, R., Gong, W.M. and Zhu, M.X. (2017), "The effect of sidewall roughness on the shaft resistance of rock-socketed piles", Acta Geotech. 12(2), 429-440. https://doi.org/10.1007/s11440-016-0470-8.
  6. Jafari, M., Gharsallaoui, H., Victor, K.H. and Holeyman, A. (2019), "End bearing response of open-ended pipe piles embedded in rock", Int. J. Rock Mech. Min. Sci., 119, 46-57. https://doi.org/10.1016/j.ijrmms.2019.04.008.
  7. Jeong, S., Ahn, S. and Seol, H. (2010), "Shear load transfer characteristics of drilled shafts socketed in rocks", Rock Mech. Rock Eng., 43(1), 41-54. https://doi.org/10.1007/s00603-009-0026-4.
  8. Kong, K.H., Kodikara, J. and Haque, A. (2006), "Numerical modelling of the side resistance development of piles in mudstone with direct use of sidewall roughness", Int. J. Rock Mech. Min. Sci., 43(6), 987-995. https://doi.org/10.1016/j.ijrmms.2006.01.002
  9. Kou, H.L., Guo, W., Zhang, M.Y. and Xu, Y.Q. (2016), "Axial resistance of long rock-socketed bored piles in stratified soils", Ocean Eng., 114, 58-65. https://doi.org/10.1016/j.oceaneng.2016.01.013.
  10. Liang, X., Cheng, Q.G., Wu, J.J. and Chen, J.M. (2016), "Model test of the group piles foundation of a high-speed railway bridge in mined-out area", Front Struct. Civ. Eng., 10(4), 488-498. https://doi.org/10.1007/s11709-016-0338-x.
  11. Li, X.Y., Bai, X.Y. and Zhang, M.Y. (2019), "Study on bearing capacity characteristics of rock socketed short pile in weathered rock site", J. Eng. Res., 7(3), 76-89.
  12. Liu, H.F., Zhu, C.Q., Meng, Q.S., Wang, X., Li, X.G. and Wu, W.J. (2018), "Model test on rock-socketed pile in reef limestone", Rock Soil Mech., 39(5), 1581-1588.
  13. Mezazigh, S. and Levacher, D. (1998), "Laterally loaded piles in sand: Slope effect on P-Y reaction curves", Can. Geotech. J., 35(3), 433-441. https://doi.org/10.1139/t98-016.
  14. Roh, Y., Kim, G., Kim, I. and Lee, J. (2019), "Effects of rock-support and inclined-layer conditions on load carrying behavior of piled rafts", Geomech. Eng., 18(4), 363-371. https://doi.org/10.12989/gae.2019.18.4.363.
  15. Schofield, A.N. (1980), "Cambridge geotechnical centrifuge operation", Geotechnique, 30(3), 227-268. https://doi.org/10.1680/geot.1980.30.3.227.
  16. Seo, H., Prezzi, M. and Salgado, R. (2013), "Instrumented static load test on rock-socketed micropile", J. Geotech. Geoenviron. Eng., 139(12), 2037-2047. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000946.
  17. Seola, H., Jeong, S., Cho, C. and You, K. (2008), "Shear load transfer for rock-socketed drilled shafts based on borehole roughness and geological strength index (GSI)", Int. J. Rock Mech. Min. Sci., 45(6), 848-861. https://doi.org/10.1016/j.ijrmms.2007.09.008.
  18. Sinnreich, J. and Ayithi, A. (2014), "Derivation of p-y curves from lateral pile load test instrument data", Geotech. Test J., 37(6), 20130127. https://doi.org/10.1520/GTJ20130127.
  19. Wang, C.D., Zhou, S.H., Wang, B.L. and Guo, P.J. (2018), "Time effect of pile-soil-geogrid-cushion interaction of rigid pile composite foundations under high-speed railway embankments", Geomech. Eng., 16(6), 589-597. https://doi.org/10.12989/gae.2018.16.6.589.
  20. Xing, H.F., Xiong, F., Wang, L.J. and Luo, Y. (2017), "Research on shaft resistance of rock-socketed piles based on the cavity expansion theory", Mar. Georesour. Geotec., 35(6), 873-877. https://doi.org/10.1080/1064119X.2016.1257670.
  21. Xing, H.F., Zhang, Z., Meng, M.H. Luo, Y. and Ye, G.B. (2014), "Centrifuge tests of superlarge-diameter rock-socketed piles and their bearing characteristics", J. Bridge. Eng., 19(6), 04014010. https://doi.org/10.1061/(ASCE)BE.1943-5592.0000582.
  22. Xing, H.F., Liu, L.L. and Luo, Y. (2019), "Effects of construction technology on bearing behaviors of rock-socketed bored piles as bridge foundations", J. Bridge. Eng., 24(4), 05019002. https://doi.org/10.1061/(ASCE)BE.1943-5592.0001368.
  23. Xu, W., Liu, B., Zhou, Y.Q. and Han, Y.H. (2017), "Construction of 8.0-m diameter rock-socketed piles in a large-scale deep excavation", Geotech. Geol. Eng., 35(5), 2455-2466. https://doi.org/10.1007/s10706-017-0229-5.
  24. Yuan, H.P., Zhao, P., Wang, Y.X., Zhou, H.L., Luo, Y. H. and Guo, P.P. (2017), "Mechanism of deformation compatibility and pile foundation optimum for long-span tower foundation in floodplain deposit zone", Int. J. Civ. Eng., 15(6), 887-894. https://doi.org/10.1007/s40999-016-0066-6.
  25. Yu, J., Cai, Y.Y. and Wu, W.B. (2013), "Effect of sediment on vertical dynamic impedance of rock-socketed pile with large diameter", J. Cent. South Univ., 20(10), 2856-2862. https://doi.org/10.1007/s11771-013-1806-2.
  26. Zhang, L. M. and Wong, E.Y.W. (2007), "Centrifuge modeling of large-diameter bored pile groups with defects", J. Geotech. Geoenviron. Eng., 133(9), 1091-1101. https://doi.org/10.1061/(ASCE)1090-0241(2007)133:9(1091).
  27. Zhang, X.L., Duan, B.C., Wang, C.Z. and Wang, D.Y. (2019), "Dynamic response analysis of lateral impact force of frame wharf with rock-socketed piles in Inland River steel sheath", Adv. Civ. Eng. 6918376. https://doi.org/10.1155/2019/6918376.
  28. Zou, J.F., Yang, T. and Deng, D.P. (2019), "Field test of the long-term settlement for the post-grouted pile in the deep-thick soft soil", Geomech. Eng., 19(2), 115-126. https://doi.org/10.12989/gae.2019.19.2.115.