WANG Long,CHEN Guoxing,HU Wei,et al.Seismic Stability of Unsaturated Soil Slopes Stabilized by Anti‑slide Piles Based on Pseudo‑dynamic Approach[J].Journal of Disaster Prevention and Mitigation Engineering,2023,43(06):1386-1394.
WANG Long,CHEN Guoxing,HU Wei,et al.Seismic Stability of Unsaturated Soil Slopes Stabilized by Anti‑slide Piles Based on Pseudo‑dynamic Approach[J].Journal of Disaster Prevention and Mitigation Engineering,2023,43(06):1386-1394. DOI: 10.13409/j.cnki.jdpme.20220509005.
Seismic Stability of Unsaturated Soil Slopes Stabilized by Anti‑slide Piles Based on Pseudo‑dynamic Approach
Based on the upper bound limit analysis theorem and the pseudo-dynamic approach, a modified horizontal slice method is proposed to calculate the work rates of soil gravity and seismic inertia forces, both characterized by evident nonlinear distribution features. Traditional plasticity theory is extended to unsaturated soils to account for the influence of soil suction on the resistance forces acting on piles. The proposed method is validated by comparing it with analytical solutions. A series of parametric analysis are conducted regarding the impacts of soil suction and pile design parameters on soil slope stability. The results show that the slope stability is underestimated by 20% ~ 50% when soil suction is not considered in practice. The suction effect depends on seismic excitations and is significantly enhanced when the seismic wave approaches its peak. The horizontal, vertical acceleration coefficients, and the soil shear modulus all have a great influence on seismic slope stability. When the pile spacing
D
1
/
d
p
≤ 4, pile reinforcement becomes obvious and increases rapidly as the internal friction angle increases. The optimum pile location commonly lies in the middle and upper part of the slope. The optimum pile location gradually decreases, and the pile reinforcement is slightly reduced as the internal friction angle increases.
Liu K Q , Liu H Y . Stability analysis of soil-rock mixture slope under earthquake [J]. Journal of Disaster Prevention and Mitigation Engineering , 2022 , 42 ( 1 ): 224 - 230 . (in Chinese)
Steedman R S , Zeng X . The influence of phase on the calculation of pseudo-static earth pressure on a retaining wall [J]. Geotechnique , 1990 , 40 ( 1 ): 103 - 112 .
Zeng X , Steedman R S . On the behavior of quay walls in earthquakes [J]. Geotechnique , 1993 , 43 : 417 - 431 .
Rao P P , Tong L L , Shi Y W . Seismic stability analysis of slopes reinforced with anti-slide piles based on pseudo-dynamic method [J]. World Earthquake Engineering , 2020 , 36 ( 1 ): 189 - 196 . (in Chinese)
Fu Y Q . Analysis on stability of reinforced slopes based on the pseudo-dynamic method [J]. Subgrade Engineering , 2022 ( 1 ): 134 - 138 . (in Chinese)
Ito T , Matsui T . Methods to estimate lateral force acting on stabilizing piles [J]. Soils and Foundations , 1975 , 15 ( 4 ): 43 - 59 .
Zheng G , Zhao J P , Zhou H Z , et al . Stability analysis of weak interlayer slopes reinforced with piles under seismic loads [J]. Journal of Chongqing University , 2019 , 42 ( 11 ): 47 - 55 . (in Chinese)
Dong J H , Wu X L , Lian B , et al . Study on dynamic calculation method for landslide prevention structure of anti-slide pile with pre-stressed anchor cable [J]. China Civil Engineering Journal , 2022 , 55 ( 11 ): 72 - 82 . (in Chinese)
Ning S , Zhuang Y , Cui X Y , et al . Stability analysis of slope reinforced with piles in anisotropic and heterogeneity soils [J]. Journal of Harbin Engineering University , 2022 , 43 ( 4 ): 529 - 535 . (in Chinese)
Vanapali S K , Fredlund D G , Pufahl D E , et al . Model for the prediction of shear strength with respect to soil suction [J]. Canadian Geotechnical Journal , 1996 , 33 ( 3 ): 379 - 392 .
Lu N , Likos W J . Unsaturated soil mechanics [M]. New York : John Wiley and Sons , 2004 .
Fredlund D G , Rahardjo H , Fredlund M D . Unsaturated soil mechanics in engineering practice [M]. New Jersey : Wiley, Hoboken , 2012 .
Fredlund D G , Xing A Q . Equations for the soil-water characteristic curve [J]. Canadian Geotechnical Journal , 1994 , 31 ( 4 ): 521 - 532 .
Bishop A W . The principle of effective stress [J]. Teknisk Ukeblad , 1959 , 39 : 859 - 863 .
Fredlund D G , Morgenstern N R , Widger R A . The shear strength of unsaturated soils [J]. Canadian Geotechnical Journal , 1978 , 15 ( 3 ): 313 - 321 .
Chen W F . Limit analysis and soil plasticity [M]. Amsterdam : Elsevier , 1975 .
Wang L , Sun D A , Yao Y P , et al . Kinematic limit analysis of three-dimensional unsaturated soil slopes reinforced with a row of piles [J]. Computers and Geotechnics , 2020 , 120 : 103428 .
Li X P , Su L , He S M , et al . Limit equilibrium analysis of seismic stability of slopes reinforced with a row of piles [J]. International Journal for Numerical and Analytical Methods in Geomechanics , 2016 , 40 ( 8 ): 1241 - 1250 .
Zhang L L , Fredlund D G , Fredlund M D , et al . Modeling the unsaturated soil zone in slope stability analysis [J]. Canadian Geotechnical Journal , 2014 , 51 ( 12 ): 1384 - 1398 .