Numerical Simulation Of The Influence Ot Freeze-thaw On Slope Stability

At present,the development of China's construction industry is relatively rapid.Especially after the national response to the strategy of revitalizing Northeast China,highway,railway and infrastructure construction in seasonal frozen land areas are more vigorous.However,the accompanying freeze-thaw disasters also increased.Due to the complexity of seasonal frozen soil itself,landslides caused by freeze-thaw conditions of slopes account for a large proportion of all kinds of disasters.Up to now,there is little research data on soil mass in cold regions,and engineering practice is more than theoretical discussion.Therefore,the stability of slopes in seasonal frozen regions in the process of freezing and thawing needs urgent scientific research and experimental research.In this paper,the formula of safety factor of melting slope is deduced by the limit equilibrium method,and then the numerical simulation of a cutting slope is carried out by the strength reduction finite element method.The simulated plastic zone penetration is used as the criterion for determining the stability of the slope.Then the safety factor obtained at this time is deduced from the limit equilibrium method.The results of the derivation form a comparative analysis,which verifies that the finite element method of strength reduction is completely applicable to the analysis of slope stability.Under feasible conditions,three-dimensional simulation of slope soil in seasonal frozen soil area is carried out to explore its stability under freeze-thaw conditions.At the same time,without changing the mechanical parameters,anti-slide piles are added into the slope body.The influence of pile diameter,pile length,pile layout and pile top constraint on the overall stability of the slope is studied by using Mohr-Columb strength theory and strength reduction method.The main research results are as follows:(1)The formula for calculating the safety factor of soil slope during melting is deduced by the limit equilibrium method,and it is obtained that with the increase of melting time,the depth increases and the safety factor decreases,so the slope has no original stability;with the decrease of effective internal friction angle and the gradual increase of slope,the safety system is established.The number decreases gradually,so the slope has no original stability;(2)The stability of slope in frozen,thawed and non-frozen regions is discussed by strength reduction method.The results show that the freezing process increases the stability of slope,the thawing process reduces the stability of slope,and the stability of slope decreases after a freezing-thawing cycle;(3)Anti-slide piles have good effect on enhancing the stability of slope,but the melting process will weaken its stability;with the increase of pile diameter,the safety factor gradually increases,but eventually tends to be stable,so the diameter of anti-slide piles should be reasonably chosen;the anti-slide piles are arranged in the range of 0.35<K<0.55,which have strong stability and constraints on the top of piles.The stronger the condition is,the higher the stability of the slope is.Therefore,if the condition permits,the reasonable arrangement of piles and the restraint conditions at the top of the slope should be improved.