Study On Stability Of Soil-Rock Combined Slope In Dongjiao Village

The soil-rock combined slope of Dongjiao Village is located in Dongjiao Village,Hezhang Township,Shexian County.The landslide body is composed of loose deposits such as Quaternary Debris.The structure is loose.It is prone to landslide disasters under the action of rainfall and earthquakes,which is harmful to the lives of lower residents.Threats to safety,property safety and adjacent roads.This paper studies the stability of the slope under rainfall and earthquakes.The simplified Janbu method and strength reduction method are used to calculate the stability of the slope under natural conditions.The seepage field,displacement field and stability of the slope under different rainfall conditions are analyzed.Numerical simulation analyzes the dynamic response and stability under earthquake action,and proposes anti-slide pile reinforcement schemes based on the comprehensive analysis results.The specific conclusions are as follows:(1)The results of the simplified Janbu method and the strength reduction method show that the slope is in a stable state when only under the action of gravity,and the sliding surface is a broken line sliding surface along the soil-rock junction.The error of the safety factor calculated by the simplified Janbu method and the strength reduction method is 0.8%?1.9%,which meets the allowable range of engineering error,indicating that the strength reduction method is feasible in this example.(2)Numerical simulation of seepage field and displacement field of Dongjiao Village slope under different rainfall conditions shows that: as the rainfall time increases,The pore water pressure of the rock-soil mass of the slope increases as a whole,the saturation and displacement increase,the flow velocity of rainwater in the slope increases as a whole,runoff is formed at the soil-rock junction,and the slope stability decreases.The maximum horizontal displacement of the slope occurs at the middle edge of the sliding body,and the maximum vertical displacement occurs at the upper edge of the sliding body.When the total rainfall is the same,the amount of change in the matrix suction is greater under the short-term heavy rainfall conditions than under the long-term weak rainfall conditions.When the rainfall intensity is constant,the longer the rainfall duration,the greater the range of the slope matrix suction and soil saturation affected by rainfall,and the smaller the slope safety factor.The longer the rainfall duration,the greater the rainfall intensity,the greater the depth affected by the pore water pressure,the shorter the time required to form a transient saturation zone,the greater the impact on the slope displacement and the greater the stability.difference.The Dong Jiao Village Slope was in an unstable state under the effects of 48 h and 96 h heavy rains.(3)Using finite element software to analyze the dynamic response and stability of the Dongjiao Village slope under different earthquakes,it can be seen that the acceleration time history curve of each node selected is similar to the waveform of the input seismic wave,and its acceleration peak is in the strong earthquake phase of the seismic wave.The amplification effect of horizontal seismic waves on slope rock and soil is greater than that of vertical seismic waves.Horizontal seismic waves have a more obvious amplifying effect on the horizontal acceleration of rock and soil,and a weaker effect on vertical acceleration.The vertical acceleration magnification coefficient of rock and soil mass under the action of horizontal seismic waves is inversely proportional to the depth,and the change trend of the horizontal acceleration magnification coefficient is not obvious.The Dongjiao Village slope is in an unstable state under the action of the EL-Centro earthquake with a peak acceleration of 0.15 g and a duration of 15s(4)The stability of Dongjiao Village slope reinforced by anti-slide piles is simulated numerically,and its reinforcement effect is analyzed.The slope reinforced by single-row piles is in a stable state under the action of earthquake;the displacement is obviously reduced under the action of heavy rain,but the anti-slide piles cannot stop the sliding of the sliding body,and the slope is in an under-stable state,so double-row anti-sliding is required Pile piles for reinforcement.The safety factor of the slope reinforced by the double-row anti-slide piles is improved under the action of heavy rain and earthquake,and is in a stable state.The displacement of the double-row anti-slide pile reinforced slope under the limit equilibrium state is significantly reduced,and the double-row anti-slide pile has a significant reinforcement effect.