Using Pile Group to Mitigate Lateral Spreading in Uniform and Stratified Liquefiable Sand Strata: Three-Dimensional Numerical Simulation

Document Type : Research Article

Authors

1 Assistant Professor of Geotechnical Engineering, Faculty of Engineering and Technology, University of Mazandaran, Babolsar, Iran.

2 University of Mazandaran

3 Associate Professor, Faculty of Engineering and Technology, University of Mazandaran, Babolsar, Iran

Abstract

According to reports from past earthquakes around the world, the phenomenon of liquefaction is one of the main hazards of earthquakes that causes damage to structures and infrastructures. The risk of liquefaction and associated lateral spreading can be reduced by various ground improvement techniques, including densification, solidification (e.g., cementation), Vibro-compaction, drainage, explosive compaction, deep soil mixing, deep dynamic compaction, permeation grouting, jet grouting, pile-pinning, and gravel drains or SCs. In this research, the effects of pile groups on reducing the potential for liquefaction during earthquakes are investigated parametrically, using three-dimensional finite element (FE) simulations via OpenSees. Saturated uniform and stratified loose sand are subjected to two realistic destructive events with different characteristics. A multi-yield-surface plasticity model, Drucker–Prager yield criterion, is considered for the dynamic analysis conducted in this study based on constitutive laws applicable to all types of soils. The objective of this research is to assess the effectiveness of the pile group based on several different factors, including area replacement ratio ( ), piles diameter, number of piles, thickness and position of liquefiable soil, and earthquake characteristics. This parametric study evaluates the effect of each of these factors on soil acceleration, lateral displacement, and excess pore pressure. The results showed that the lateral displacement and excess pore pressure decrease, as the area replacement ratio, number, and diameter of the pile increase. Besides, the responses of the saturated stratified sand strata are not only dependent on the thickness of the liquefiable layer but are also highly influenced by its position. The presence of a liquefiable layer at lower depths, although acting as an isolate relative to the acceleration, can increase lateral displacements. Also, according to the results, there is an appropriate correlation between the variations of lateral displacement rate of piles and soil and earthquake parameters including Arias intensity, the time corresponding to the PGA, and the number of significant excitation cycles. Therefore, the results of this study may be applicable for other earthquakes.

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Main Subjects


[1] Guideline for Assessment of Soil Liquefaction Potential, Consequences and Mitigation Methods No.525, 2012 (in Persian).
[2] M. Fallahzadeh, A. Haddad, Y. Jafarian, C. Lee, Seismic performance of end-bearing piled raft with countermeasure strategy against liquefaction using centrifuge model tests, Bulletin of Earthquake Engineering, 17(11) (2019) 5929-5961.
[3] A. Elgamal, J. Lu, D. Forcellini, Mitigation of liquefaction-induced lateral deformation in a sloping stratum: Three-dimensional numerical simulation, Journal of geotechnical and geoenvironmental engineering, 135(11) (2009) 1672-1682.
[4] X. Zhang, L. Tang, X. Li, X. Ling, A. Chan, Effect of the combined action of lateral load and axial load on the pile instability in liquefiable soils, Engineering Structures, 205 (2020) 110074.
[5] A. Ebeido, A. Elgamal, K. Tokimatsu, A. Abe, Pile and Pile-Group Response to Liquefaction-Induced Lateral Spreading in Four Large-Scale Shake-Table Experiments, Journal of Geotechnical and Geoenvironmental Engineering, 145(10) (2019) 04019080.
[6] Rahmani, A. Pak, Dynamic behavior of pile foundations under cyclic loading in liquefiable soils, Computers and Geotechnics, 40 (2012) 114-126.
[7] L. Su, H.-P. Wan, S. Abtahi, Y. Li, X.-Z. Ling, Dynamic response of soil-pile-structure system subjected to lateral spreading: shaking table test and parallel finite element simulation, Canadian Geotechnical Journal, (ja) (2019).
[8] R. Sarkar, S. Bhattacharya, B. Maheshwari, Seismic requalification of pile foundations in liquefiable soils, Indian Geotechnical Journal, 44(2) (2014) 183-195.
[9] S. Hui, L. Tang, X. Zhang, Y. Wang, X. Ling, B. Xu, An investigation of the influence of near-fault ground motion parameters on the pile’s response in liquefiable soil, Earthquake Engineering and Engineering Vibration, 17(4) (2018) 729-745.
[10] A. Asgari, M. Oliaei, M. Bagheri, Numerical simulation of improvement of a liquefiable soil layer using stone column and pile-pinning techniques, Soil Dynamics and Earthquake Engineering, 51 (2013) 77-96.
[11] J. Lu, P. Kamatchi, A. Elgamal, Using Stone Columns to Mitigate Lateral Deformation in Uniform and Stratified Liquefiable Soil Strata, International Journal of Geomechanics, 19(5) (2019) 04019026.
[12] L. He, A. Elgamal, M. Hamada, J. Meneses, Shadowing and group effects for piles during earthquake-induced lateral spreading, in:  Proc. 14th World Conference on Earthquake Engineering, 2008, pp. 12-17.
[13] K. Panaghi, A. Mahboubi, A. Mahdavian, The effect of earthquake motion characteristics on potentially liquefiable pile-pinned sloping ground, Bulletin of Earthquake Engineering, 17(4) (2019) 1891-1917.
[14] X. Zhang, L. Tang, X. Ling, A.H.C. Chan, J. Lu, Using peak ground velocity to characterize the response of soil-pile system in liquefying ground, Engineering geology, 240 (2018) 62-73.
[15] Jeremić, Development of geotechnical capabilities in OpenSees, Pacific Earthquake Engineering Research Center, College of Engineering …, 2001.
[16] S. Mazzoni, F. McKenna, M.H. Scott, G.L. Fenves, OpenSees command language manual, Pacific Earthquake Engineering Research (PEER) Center, 264 (2006).
[17] H.K. Law, I.P. Lam, Application of periodic boundary for large pile group, Journal of Geotechnical and Geoenvironmental Engineering, 127(10) (2001) 889-892.
[18] A. Klar, S. Frydman, R. Baker, Seismic analysis of infinite pile groups in liquefiable soil, Soil Dynamics and Earthquake Engineering, 24(8) (2004) 565-575.
[19] Z. Cheng, B. Jeremić, Numerical modeling and simulation of pile in liquefiable soil, Soil Dynamics and Earthquake Engineering, 29(11-12) (2009) 1405-1416.
[20] J.H. Prevost, A simple plasticity theory for frictional cohesionless soils, International Journal of Soil Dynamics and Earthquake Engineering, 4(1) (1985) 9-17.
[21] A. Elgamal, Z. Yang, E. Parra, A. Ragheb, Modeling of cyclic mobility in saturated cohesionless soils, International Journal of Plasticity, 19(6) (2003) 883-905.
[22] Elgamal, Z. Yang, E. Parra, Computational modeling of cyclic mobility and post-liquefaction site response, Soil Dynamics and Earthquake Engineering, 22(4) (2002) 259-271.
[23] M.A. Biot, Mechanics of deformation and acoustic propagation in porous media, Journal of applied physics, 33(4) (1962) 1482-1498.
[24] A.H.-C. Chan, A unified finite element solution to static and dynamic problems of geomechanics, Swansea University, 1988.
[25] D.W. Wilson, Soil-pile-superstructure interaction in liquefying sand and soft clay, Citeseer, 1998.
[26] V.M. Taboada-Urtuzuastegui, R. Dobry, Centrifuge modeling of earthquake-induced lateral spreading in sand, Journal of geotechnical and geoenvironmental engineering, 124(12) (1998) 1195-1206.
[27] M. Hamada, Large ground deformations and their effects on lifelines: 1983 Nihonkai-Chubu earthquake, Japanese Case Studies, (1992).