The Responses of an End-Bearing Pile to Adjacent Multipropped Excavation: 3D Numerical Modelling
It is well recognised that superstructure load is transferred to surrounding soil through piled foundation. Consequently, the high stress regime (stress bulb) is generated surrounding of the pile. On the other hand, the excavation in the ground inevitably results in the ground movement due to induced-stress release. These excavations are sometimes inevitable to be constructed adjacent to existing piled foundations. This condition leads to a big challenge for engineers to assess and protect the integrity of piled foundation. This research presents three-dimensional coupled consolidation analyses (using clay hypoplastic constitutive model which takes account of small-strain stiffness) to investigate the responses of an end-bearing pile due to adjacent excavation at different depths in soft clay. The effects of excavation depths (i.e., formation level) relative to pile were investigated by simulating the excavation near the pile shaft (i.e., case S) and next to (case T). It was revealed that the maximum induced bending moment in the pile after completion of excavation in all the cases is much less than the pile bending moment capacity (i.e. 800 kNm). Comparing the induced deflection of the end-bearing pile in the case T, the pile deflection in case S is higher. Moreover the piles in cases of S and T were subjected to significant dragload due to negative skin friction.
Finno, R J, Lawrence, S A, Allawh, N F, and Harahap, I S. "Analysis of performance of pile groups adjacent to deep excavation". Journal of Geotechnical and Geoenvironmental Engineering, ASCE; 117 (June 1991): 934–955. doi:10.1061/(ASCE)0733-9410(1991)117:6(934).
Goh, A T C, Wong, K S, Teh, C I, and Wen, D. “Pile response adjacent to braced excavation”. Journal of Geotechnical and Geoenvironmental Engineering, ASCE; 129 (April 2003): 383–386. doi:10.1061/(asce)1090-0241(2003)129:4(383).
Gudehus, Gerd, Angelo Amorosi, Antonio Gens, Ivo Herle, Dimitrios Kolymbas, David Mašín, David Muir Wood, et al. “The Soilmodels.info Project.” International Journal for Numerical and Analytical Methods in Geomechanics 32, no. 12 (August 25, 2008): 1571–1572. doi:10.1002/nag.675.
Hong, Y., and Charles W.W. Ng. “Base Stability of Multi-Propped Excavations in Soft Clay Subjected to Hydraulic Uplift.” Canadian Geotechnical Journal 50, no. 2 (February 2013): 153–164. doi:10.1139/cgj-2012-0170.
Hsieh, Pio-Go, and Chang-Yu Ou. “Shape of Ground Surface Settlement Profiles Caused by Excavation.” Canadian Geotechnical Journal 35, no. 6 (1998): 1004–1017. doi:10.1139/cgj-35-6-1004.
Hsiung, Bin-Chen Benson. “A Case Study on the Behaviour of a Deep Excavation in Sand.” Computers and Geotechnics 36, no. 4 (May 2009): 665–675. doi:10.1016/j.compgeo.2008.10.003.
Hu, Z F, Z Q Yue, J Zhou, and L G Tham. “Design and Construction of a Deep Excavation in Soft Soils Adjacent to the Shanghai Metro Tunnels.” Canadian Geotechnical Journal 40, no. 5 (October 2003): 933–948. doi:10.1139/t03-041.
Korff, Mandy, Robert J. Mair, and Frits A. F. Van Tol. “Pile-Soil Interaction and Settlement Effects Induced by Deep Excavations.” Journal of Geotechnical and Geoenvironmental Engineering 142, no. 8 (August 2016): 04016034. doi:10.1061/(asce)gt.1943-5606.0001434.
Lee, C J, and N g, C W W. “Development of down drag on piles and pile groups in consolidating soil”. Journal of Geotechnical and Geoenvironmental Engineering, ASCE; 130 (February 2004): 905-914. doi: 10.1061/(asce)1090-0241(2004)130:9(905).
Leung, C F, Chow, Y K, and Shen, R F. “Behavior of pile subject to excavation-induced soil movement”. Journal of Geotechnical and Geoenvironmental Engineering, ASCE; 126 (November 2000): 947-954. doi: 10.1061/(asce)1090-0241(2000)126:11(947).
Leung, C F, Lim, J K, Shen, R F, and Chow, Y K. “Behavior of pile groups subject to excavation-induced soil movement”. Journal of Geotechnical and Geoenvironmental Engineering, ASCE; 129 (January 2003): 58-65. doi:10.1061/(asce)1090-0241(2003)129:1(58).
Leung, C F, Ong, DEL., Shen, R F., and Chow, Y K. “Pile behavior due to excavation-induced soil movement in clay II: Collapsed wall”. Journal of Geotechnical and Geoenvironmental Engineering, ASCE; 132 (January 2006): 45-53. doi.org/10.1061/(asce)1090-0241(2006)132:1(45).
Liu, Guang, Ming Cai, and Ming Huang. “Mechanical Properties of Brittle Rock Governed by Micro-Geometric Heterogeneity.” Computers and Geotechnics 104 (December 2018): 358–372. doi:10.1016/j.compgeo.2017.11.013.
Liyanapathirana, D.S., and R. Nishanthan. “Influence of Deep Excavation Induced Ground Movements on Adjacent Piles.” Tunnelling and Underground Space Technology 52 (February 2016): 168–181. doi:10.1016/j.tust.2015.11.019.
Mašín, D. “A Hypoplastic Constitutive Model for Clays.” International Journal for Numerical and Analytical Methods in Geomechanics 29, no. 4 (2005): 311–336. doi:10.1002/nag.416.
Mašín, David, and Ivo Herle. “State Boundary Surface of a Hypoplastic Model for Clays.” Computers and Geotechnics 32, no. 6 (September 2005): 400–410. doi:10.1016/j.compgeo.2005.09.001.
Mašín, David. “3D Modeling of an NATM Tunnel in High K0 Clay Using Two Different Constitutive Models.” Journal of Geotechnical and Geoenvironmental Engineering 135, no. 9 (September 2009): 1326–1335. doi:10.1061/(asce)gt.1943-5606.0000017.
Ng, Charles WW, B Simpson, M L Lings, and DFT Nash. “Numerical Analysis of a Multipropped Excavation in Stiff Clay.” Canadian Geotechnical Journal 35, no. 1 (February 1998): 115–130. doi:10.1139/t97-074.
Ng, C W W, Yau, T L Y, Li, J H M, and Tang, W H. “New failure load criterion for large diameter bored piles in weathered geomaterials”. Journal of Geotechnical and Geoenvironmental Engineering, ASCE; 127 (June 2001): 488-498. doi:10.1061/(ASCE)1090-0241(2001)127:6(488)
NG, C.W.W., Y. HONG, G.B. LIU, and T. LIU. “Ground Deformations and Soil–structure Interaction of a Multi-Propped Excavation in Shanghai Soft Clays.” Géotechnique 62, no. 10 (October 2012): 907–921. doi:10.1680/geot.10.p.072.
Ng, Charles W. W., Jiaqi Wei, Harry Poulos, and Hanlong Liu. “Effects of Multipropped Excavation on an Adjacent Floating Pile.” Journal of Geotechnical and Geoenvironmental Engineering 143, no. 7 (July 2017): 04017021. doi:10.1061/(asce)gt.1943-5606.0001696.
Nishanthan, Ravintharakumaran, D. S. Liyanapathirana, and Chin Jian Leo. “Shielding Effect in Pile Groups Adjacent to Deep Unbraced and Braced Excavations.” International Journal of Geotechnical Engineering (July 8, 2016): 1–13. doi:10.1080/19386362.2016.1200270.
Ong, DEL, Leung, C F, and Chow, Y K. “Pile behavior due to excavation-induced soil movement in clay”. I: Stable Wall. Journal of Geotechnical and Geoenvironmental Engineering, ASCE; 132 (January 2006): 36-44. doi:10.1061/(ASCE)1090-0241(2006)132:1(36).
Ong, DEL, Leung, C F, and Chow, Y K. “Behavior of pile groups subject to excavation-induced soil movement in very soft clay”. Journal of Geotechnical and Geoenvironmental Engineering, ASCE; 135 (October 2009): 1462-1472. doi.org/10.1061/(asce)gt.1943-5606.0000095.
Poulos H G, and Chen L T. “Pile response due to excavation-induced lateral soil movement”. J Geotech Geoenviron Eng; 123 (February 1997): 94-99. doi:10.1061/(ASCE)1090-0241(1997)123:2(94).
Soomro, Mukhtiar Ali, Dildar Ali Mangnejo, Riaz Bhanbhro, Noor Ahmed Memon, and Muneeb Ayoub Memon. “3D Finite Element Analysis of Pile Responses to Adjacent Excavation in Soft Clay: Effects of Different Excavation Depths Systems Relative to a Floating Pile.” Tunnelling and Underground Space Technology 86 (April 2019): 138–155. doi:10.1016/j.tust.2019.01.012.
Zhang, Runhong, Wengang Zhang, and Anthony Teck Chee Goh. “Numerical Investigation of Pile Responses Caused by Adjacent Braced Excavation in Soft Clays.” International Journal of Geotechnical Engineering (September 6, 2018): 1–15. doi:10.1080/19386362.2018.1515810.
Shakeel, M., and Charles W.W. Ng. “Settlement and Load Transfer Mechanism of a Pile Group Adjacent to a Deep Excavation in Soft Clay.” Computers and Geotechnics 96 (April 2018): 55–72. doi:10.1016/j.compgeo.2017.10.010.
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