Seismic stability analysis of two-stage slopes reinforced with one row of piles. Issue 153 (February 2022)

• Record Type: Journal Article
• Authors: Li, Zhaoying; Xiao, Shiguo
• Is Part Of: Soil dynamics and earthquake engineering. Issue 153(2022)
• Publication Date: 2022-02
• Subjects: Seismic stability -- Stabilizing piles -- Two-stage slope -- Upper-bound limit analysis -- Axial force; Soil dynamics -- Periodicals; Earthquake engineering -- Periodicals; Sols -- Dynamique -- Périodiques; Génie parasismique -- Périodiques; 624.176205
• DOI: 10.1016/j.soildyn.2021.107079
• Languages: English
• ISSNs: 0267-7261

Abstract

Abstract: Seismic stability of a two-stage soil slope reinforced by one row of piles is analyzed using the upper bound theorem combined with pseudo-static method considering the pile axial force. For a specified safety factor of the piled slope, explicit expression of the required pile shear resistance is derived, in which the effect of axial force of the piles on the potential slide mass omitted in most of previous studies is reasonably introduced. Analysis results of examples show that the pile shear resistance and potential slip surface by the proposed method are in good agreement with those by numerical simulation. The pile reinforcement effect on the slope is operational under smaller seismic conditions, whereas it is limited and not significant with the increase of the seismic excitations. The pile shear resistance and range of the critical slide mass increase with the horizontal seismic acceleration coefficient. Compared with the existing results omitting the pile axial force, more conservative upper bound solutions of the pile shear resistance are obtained by the proposed method, especially under higher design safety factor and seismic loads. Widening the bench and constructing the pile row near the slope crest are conducive to practicably optimize the reinforcement effect on the two-stage slope under seismic excitations. Highlights: Seismic stability analysis method for piled two-stage soil slopes considering the pile axial force is put forward. More conservative solution of the required pile shear resistance can be obtained if the pile axial force is considered. The required pile shear resistance is negatively related to vertical seismic coefficients under higher horizontal ones. Piles can effectively improve the slope stability in smaller seismic cases but insignificantly under higher ones. It is rational that the piles are located within the upper stage especially at the slope crest in seismic cases.