DOI QR코드

DOI QR Code

A parametric study of settlement and load transfer mechanism of piled raft due to adjacent excavation using 3D finite element analysis

  • Karira, Hemu (Department of Civil Engineering, Mehran University of Engineering and Technology, Shaheed Zulfiqar Ali Bhutto Campus) ;
  • Kumar, Aneel (Department of Civil Engineering, Mehran University of Engineering and Technology) ;
  • Hussain Ali, Tauha (Department of Civil Engineering, Mehran University of Engineering and Technology) ;
  • Mangnejo, Dildar Ali (Department of Civil Engineering, Mehran University of Engineering and Technology, Shaheed Zulfiqar Ali Bhutto Campus) ;
  • Mangi, Naeem (Department of Civil Engineering, Quaid-e-Awam University of Engineering, Science & Technology)
  • 투고 : 2022.04.24
  • 심사 : 2022.06.26
  • 발행 : 2022.07.25

초록

The urbanization and increasing rate of population demands effective means of transportation system (basement and tunnels) as well as high-rise building (resting on piled foundation) for accommodation. Therefore, it unavoidable to construct basements (i.e., excavation) nearby piled foundation. Since the basement excavation inevitably induces soil movement and stress changes in the ground, it may cause differential settlements to nearby piled raft foundation. To understand settlement and load transfer mechanism in the piled raft due to excavation-induced stress release, numerical parametric studies are carried out in this study. The effects of excavation depths (i.e., formation level) relative to piled raft were investigated by simulating the excavation near the pile shaft (i.e., He/Lp=0.67), next to (He/Lp=1.00) and below the pile toe (He/Lp=1.33). In addition, effects of sand density and raft fixity condition were investigated. The computed results have revealed that the induced settlement, tilting, pile lateral movement and load transfer mechanism in the piled raft depends upon the embedded depth of the diaphragm wall. Additional settlement of the piled raft due to excavation can be account for apparent loss of load carrying capacity of the piled raft (ALPC). The highest apparent loss of piled raft capacity ALPC (on the account of induced piled raft settlement) of 50% was calculated in in case of He/Lp = 1.33. Furthermore, the induced settlement decreased with increasing the relative density from 30% to 90%. On the contrary, the tilting of the raft increases in denser ground. The larger bending moment and lateral force was induced at the piled heads in fixed and pinned raft condition.

키워드

과제정보

The authors would like to acknowledge the financial support provided by Mehran University of Engineering & Technology, Jamshoro, Sindh and Pakistan.

참고문헌

  1. Atkinson, J.H., Richardson, D. and Stallebrass, S.E. (1990), "Effect of recent stress history on the stiffness of over consolidated soil", Geotechnique, 40(4), 531-540. https://doi.org/10.1680/geot.1990.40.4.531.
  2. Bai, X.D., Cheng, W.C. and Li, G. (2021), "A comparative study of different machine learning algorithms in predicting EPB shield behaviour: a case study at the Xi'an metro, China", Acta Geotechnica, 16(12), 4061-4080. https://doi.org/10.1007/s11440-021-01383-7.
  3. CEN (2001), Eurocode 7 part 1: Geotechnical design: General rules, Final Draft prEN 1997-1. European Committeef or Standardization (CEN), Brussels.
  4. Finno, R.J., Lawrence, S.A., Allawh, N.F. and Harahap, I.S. (1991), "Analysis of performance of pile groups adjacent to deep excavation", J. Geotech. Eng., 117(6), 934-955. https://doi.org/10.1061/(ASCE)0733-9410(1991)117:6(934).
  5. Francescon, M. (1983), "Model pile tests in clay: Stresses and displacements due to installation and axial loading", PhD thesis, Cambridge Univ., Cambridge, U.K.
  6. Goh, A.T.C., Wong, K.S., Teh, C.I. and Wen, D. (2003), "Pile response adjacent to braced excavation", J. Geotech. Geoenviron. Eng., 129(4), 383-386. https://doi.org/10.1061/(ASCE)1090-0241(2003)129:4(383).
  7. Gudehus, G. (1996), "A comprehensive constitutive equation for granular materials", Soils Found., 36(1), 1-12. https://doi.org/10.3208/sandf.36.1.
  8. Herle, I. and Gudehus, G. (1999), "Determination of parameters of a hypoplastic constitutive model from properties of grain assemblies", Mech. Cohesive-frictional Mater.: Int. J. Exper. Model. Comput. Mater. Struct., 4(5), 461-486. https://doi.org/10.1002/(sici)10991484(199909)4:5%3C461::aid-cfm71%3E3.0.co;2-p.
  9. Hibbitt, D., Karlsson, B.I. and Sorensen, E.P. (2010), Abaqus user's manual, version 6.10.2. Hibbitt, Karlsson & Sorensen Inc;, Providence, RI, USA.
  10. Hong, Y., Koo, C.H., Zhou, C., Ng, C.W. and Wang, L.Z. (2017), "Small strain path-dependent stiffness of Toyoura sand: Laboratory measurement and numerical implementation", Int. J. Geomech., 17(1), 04016036. https://doi.org/10.1061/(asce)gm.1943-5622.0000664.
  11. Hsiung, B.C.B. (2009), "A case study on the behaviour of a deep excavation in sand", Comput. Geotech., 36(4), 665-675. https://doi.org/10.1016/j.compgeo.2008.10.003.
  12. Hu, W., Cheng, W.C., Wen, S. and Rahman, M.M. (2021), "Effects of chemical contamination on microscale structural characteristics of intact loess and resultant macroscale mechanical properties", Catena, 203, 105361. https://doi.org/10.1016/j.catena.2021.105361.
  13. Hu, W., Cheng, W.C., Wang, L. and Xue, Z.F. (2022), "Microstructural characteristics deterioration of intact loess under acid and saline solutions and resultant macro-mechanical properties", Soil Tillage Res., 220, 105382. https://doi.org/10.1016/j.still.2022.105382.
  14. Ishihara, K. (1993), "Liquefaction and flow failure during earthquakes", Geotechnique, 43(3), 351-415. https://doi.org/10.1680/geot.1993.43.3.351
  15. ISSMFE (1985), "Axial pile loading test - Part I: Static loading", Geotech. Test. J., 8(2), 79-80, https://doi.org/10.1520/GTJ10514J.
  16. Jaky, J. (1944), The coefficient of earth pressure at rest", J. Soc. Hungarian Arch. Eng., 355-8 [in Hungarian].
  17. Korff, M., Mair, R. and Van Tol, F.A.F. (2016), "Pile-soil interaction and settlement effects induced by deep excavations", J. Geotech. Geoenviron. Eng., 138(7), 04016034. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001434.
  18. Liyanapathirana, D.S. and Nishanthan, R. (2016), "Influence of deep excavation induced ground movements on adjacent piles", Tunn. Undergr. Sp. Tech., 52, 168-181. https://doi.org/10.1016/j.tust.2015.11.019.
  19. Lee, C.J. and Chiang, K.H. (2007), "Responses of single piles to tunnelling-induced soil movements in sandy ground", Can. Geotech. J., 44, 1224-1241. https://doi.org/10.1139/T07-050.
  20. Lu, H., Shi, J., Ng, C.W.W. and Lv, Y. (2020), "Three-dimensional centrifuge modeling of the influence of side-by-side twin tunneling on a piled raft", Tunn. Undergr. Sp. Tech., 103, 103486. https://doi.org/10.1016/j.tust.2020.103486.
  21. Maeda, K. and Miura, K. (1999), "Relative density dependency of mechanical properties of sands", Soils Found., 39(1), 69-79. https://doi.org/10.3208/sandf.39.69.
  22. Niemunis, A. and Herle, I. (1997), "Hypoplastic model for cohesionless soils with elastic strain range", Mech. Cohesive-frictional Mater.: Int. J. Exper. Model. Comput. Mater. Struct., 2(4), 279-299. https://doi.org/10.1002/(SICI)1099-1484(199710)2:4<279::AID-CFM29>3.0.CO;2-8.
  23. Ng, C.W., Wei, J., Poulos, H. and Liu, H. (2017), "Effects of multipropped excavation on an adjacent floating pile", J. Geotech. Geoenviron. Eng., 143(7), 04017021. https://doi.org/10.1061/(ASCE)GT.1943-5606.0001696.
  24. Ng, C.W., Shakeel, M., Wei, J. and Lin, S. (2021), "Performance of existing piled raft and pile group due to adjacent multipropped excavation: 3D centrifuge and numerical modeling", J. Geotech. Geoenviron. Eng., 147(4), 04021012. https://doi.org/10.1061/(ASCE)GT.1943-5606.0002501
  25. Ong, D.E., Leung, C.E. and Chow, Y.K. (2006), "Pile behavior due to excavation-induced soil movement in clay. I: Stable wall", J. Geotech. Geoenviron. Eng., 132(1), 36-44. https://doi.org/10.1061/(ASCE)1090-0241(2006)132:1(36).
  26. Ong, D.E.L., Leung, C.F. and Chow, Y.K. (2009), "Behavior of pile groups subject to excavation-induced soil movement in very soft clay", J. Geotech. Geoenviron. Eng., 135(10), 1462-1474. https://doi.org/10.1061/(ASCE)GT.1943-5606.0000095.
  27. Poulos, H.G. (2001), "Piled raft foundations: design and applications", Geotechnique, 51(2), 95-113. https://doi.org/10.1680/geot.2001.51.2.95.
  28. Shi, J., Liu, G., Huang, P. and Ng, C.W.W. (2015), "Interaction between a large-scale triangular excavation and adjacent structures in Shanghai soft clay", Tunn. Undergr. Sp. Tech., 50, 282-295. https://doi.org/10.1016/j.tust.2015.07.013.
  29. Shi, J., Wei, J., Ng, C.W. and Lu, H. (2019), "Stress transfer mechanisms and settlement of a floating pile due to adjacent multi-propped deep excavation in dry sand", Comput. Geotech., 116, 103216. https://doi.org/10.1016/j.compgeo.2019.103216.
  30. Soomro, M.A., Mangnejo, D.A., Saand, A. and Hong, Y. (2021a), "Responses of a masonry facade to multi-propped deep excavation-induced ground deformations: 3D numerical parametric study", Eur. J. Environ. Civil Eng., 1-29. https://doi.org/10.1080/19648189.2021.1926336.
  31. Soomro, M.A., Mangnejo, D.A., Saand, A., Mangi, N. and Auchar Zardari, M. (2021b), "Influence of stress relief due to deep excavation on a brick masonry wall: 3D numerical predictions", Eur. J. Environ. Civil Eng., 1-24. https://doi.org/10.1080/19648189.2021.2004450.
  32. Soomro, M.A., Mangnejo, D.A., Saand, A. and Mangi, N. (2021c), "3D numerical analysis of a masonry facade subjected to excavation-induced ground deformation", Int. J. Geotech. Eng., 1-13. https://doi.org/10.1080/19386362.2021.1937853.
  33. Soomro, M.A., Saand, A., Mangi, N., Mangnejo, D.A., Karira, H., and Liu, K. (2021d), "Numerical modelling of effects of different multipropped excavation depths on adjacent single piles: comparison between floating and end-bearing pile responses", Eur. J. Environ. Civil Eng., 25(14), 2592-2622. https://doi.org/10.1080/19648189.2019.1638312.
  34. Soomro, M.A., Mangi, N., Memon, A.H. and Mangnejo, D.A. (2022a), "Responses of high-rise building resting on piled raft to adjacent tunnel at different depths relative to piles", Geomech. Eng., 29(1), 25-40. https://doi.org/10.12989/gae.2022.29.1.025.
  35. Soomro, M.A., Kumar, M., Mangi, N., Mangnejo, D.A. and Cui, Z. D. (2022b), "Parametric study of twin tunneling effects on piled foundations in stiff clay: 3D finite-element approach", Int. J. Geomech., 22(6), 04022079. https://doi.org/10.1061/(ASCE)GM.1943-5622.0002386.
  36. Soomro, M.A., Liu, K., Mangnejo, D.A. and Mangi, N. (2022c), "Effects of twin excavations with different construction sequence on a brick masonry wall: 3D finite element approach", Structures, 41, 866-886. https://doi.org/10.1016/j.istruc.2022.05.060.
  37. Tan, Y., Huang, R., Kang, Z. and Bin, W. (2016), "Covered semi-top-down excavation of subway station surrounded by closely spaced buildings in downtown Shanghai: Building response", J. Perform. Constr. Fac., 30(6), 04016040. https://doi.org/10.1061/(ASCE)CF.1943-5509.0000892.
  38. Wang, L., Cheng, W.C. and Xue, Z.F. (2022), "Investigating microscale structural characteristics and resultant macroscale mechanical properties of loess exposed to alkaline and saline environments", Bull. Eng. Geol. Environ., 81(4), 1-17. https://doi.org/10.1007/s10064-022-02640-z.
  39. Xue, Z.F., Cheng, W.C., Wang, L. and Song, G. (2021), "Improvement of the shearing behaviour of loess using recycled straw fiber reinforcement", KSCE J. Civil Eng., 25(9), 3319-3335. https://doi.org/10.1007/s12205-021-2263-3.
  40. Zhang, R., Zheng, J., Pu, H. and Zhang, L. (2011), "Analysis of excavation induced responses of loaded pile foundations considering unloading effect", Tunn. Undergr. Sp. Tech., 26(2), 320-335. https://doi.org/10.1016/j.tust.2010.11.003.
  41. Zhang, L.M. and Ng, A.M.Y. (2005), "Probabilistic limiting tolerable displacements for serviceability limit state design of foundations", Geotechnique, 55(2), 151-161. https://doi.org/10.1680/geot.2005.55.2.151.