3D Seismic Stability Of Step Slope Reinforced With Piles

Recently,slope engineering has always been an important area of study in geotechnical engineering,and gets many scholars' attention.Earthquakes are a major trigger factor for the failure of slopes.When the stability of the slope is insufficient,the slope is often reinforced.Piles have proven to be a commonly used and effective reinforcement method.Therefore,in this paper,based on the upper bound of limit analysis,the step slope reinforced with piles is taken to research the seismic stability of slopes.The main research works in this paper can be detailed as follows:(1)The quasi-static method is used to investigate the seismic stability of step slope reinforced with piles.Based on the upper bound of limit analysis and the strength technique,a horn failure mechanism is adopted to calculate the safety factors of step slope reinforced with piles.Then,through parameter analysis,the influence of seismic force,piles position,piles structure parameters,slope angles and steps width on the stability of slope is obtained,and the stability chart is drawn to strengthen the slope under the ground conditions.Design provides a reference basis.Finally,this paper provides guidance for the reinforcement design of slopes combined with the actual project.(2)The Newmark sliding-block analysis is used to explore the seismic stability of slopes reinforced with piles.Firstly,based on the upper limit theorem of limit analysis,the explicit expression of the yield acceleration coefficient is obtained.In order to better interpret each factor effect of slope stability under seismic force,parametric analysis is presented in this paper.Secondly,the angular acceleration of the sliding block is derived by the moment balance equation,and the final seismic displacement of the slope reinforced with piles is obtained by the second integral.Finally,combined with the actual example,three seismic records were selected to calculate the seismic displacement of the slope reinforced with piles,and the influence of earthquake on the slope stability was explored to provide reference for the seismic stability and seismic design of the slope.(3)Based on the orthogonal design principle,the sensitivity analysis of each influencing factor of step slope under the pseudo-static method and Newmark sliding-block analysis is explored respectively.In this paper,the two-stage slope reinforced with piles is used as an example to design an orthogonal graph for the factors affecting the stability of the slope.Under the two methods,the sensitivity order which affects the seismic stability of slope is distinguished.And corresponding engineering recommendations are given in combination with engineering practice.