Numerical Simulation Of The Interaction Mechanism Between Nanping Tunnel And Landslide

With the continuous development of the western development strategy,economic development has brought about more traffic construction and is constrained by the constraints of geographical location.The construction of highways and railways across mountainous regions has become inevitable.Due to the complexity of the terrain and geological conditions in mountainous areas and the frequent occurrence of natural disasters such as rainfall and earthquakes,the construction of tunnels in these areas often induce landslides.It can be seen that when the tunnel is on a hillside,combined with artificial,rainfall,earthquake and other factors acting on the hillside,usually cause the deformation of the slope,which causes the tunnel disease phenomenon has become very common,and the resulting follow-up The impact is usually very serious.Therefore,it is very necessary and urgent for the in-depth study of tunnel-landslide interaction mechanism.This paper takes the Da Zhun Railway crossing an unstable loess slope as an example.Based on the numerical simulation and on-site monitoring methods,the interaction mechanism between the tunnel and the slope is studied.The main research work and achievements carried out by the thesis are as follows:(1)Carry out on-site engineering geological surveys,indoor tests,etc.,generalized the geological model and mechanical model of the research object,and obtained related calculation parameters such as c,?,and so on.(2)Studying the influence of slope stability after tunnel excavation under different working conditions and different reinforcement methods,and analyzing the influence of slope deformation on the stress and strain of the tunnel structure.(3)Considering the influence of rainfall infiltration on the seepage of unsaturated soils,the influence of rainfall duration on the internal pore water pressure,the change of slope saturation and the influence of slope stability are analyzed.The analysis shows that the position of the saturation contour is 1 is consistent with the interface where the pore water pressure is 0;with the rainfall infiltration,the safety factor of the slope decreases from 1.11 to 0.85,and the slope is transformed from the under-stable state.Into a state of destruction.(4)According to the change of safety factor under different slope reinforcement methods,it can be seen that the safety factor of the original slope is 1.11,and the safety factor after the slope is 1.13,both are unstable;after the comprehensive treatment,the safety factor of the slope is 1.15,and the slope reaches the slope stability.The safety factor requirements ultimately play a governance role.(5)It can be seen from the on-site monitoring data that after the completion of the treatment,the horizontal displacement of the slope and the displacement difference of the deep hole are 0,which tends to be stable;the horizontal convergence of the tunnel is maintained at 3.6 cm and the dome settlement is maintained at 6.7 cm.The fixed value indicates that the slope and the tunnel are in a stable state and have achieved the effect of governance.