The Effect Analysis Of Considering Fluid-solid Coupling On The Landslide Stability

In this paper,using Lama old landslide to be as research object,according to the interaction of coupling stress and seepage field,analysis and calculation of the stress and seepage field coupling is expanded considering groundwater effect. The following results are obtained:(1)on the basis of the study of a large number of refererces,it summarizes research results of the interaction of coupling stress and seepage field.(2)the effect of between groundwater and the landslide is divided into three categories:physical effects include lubrication action,soften and argillation etc;Chemistry effects include ion exchanges,hydration,dissolution,hydrolysis,redox; Mechnical function include pore wate pressure,dynamic water pressure and uplift force.Influence of groundwater on the landslide stability is produced by reducing the effective stress and reducing the friction resistance,increasing downslide force.(3)groundwater dynamics mechanism is expounded,Essence of pore water pressure is that the pore water pressure reduce the effective normal stress, then the shear strength of the landslide mass is reducing, so that the landslide is sliding instability;Hydrodynamic pressure is essentially producing hydrodynamic pressure on the landslide mass,its direction is pointing to the empty surface,increasing downslide force reduce the landslide stability.(4)numerical simulation results show that the distribution of stress field in the landslide is accordance with the general distribution law of inner stress field of landslide, principal stress and the shearing stress are concentrated in the sliding zone and toe of slope,it is obvious stress concentration phenomenon,and unfavorable for the stability of the landslide.(5) through numerical simulation,it shows that the surface excavation and backfilling load,rainfall and surface water infiltration making rise ground water level has influence on the stability of the landslide,and through the1-1’profile and3-3’profile in the third phase the comparison of increasing displacement,it can be concluded that the higher the underground water level is,the greater the impact on the stability of the landslide.(6)the seepage field analysis can be concluded that the maximum pore water pressure in the camp and switching station location sliding zone,indicating that the slide zone is relatively gentle at this position,when the seepage field reach stable seepage, groundwater is easily accumulation at this position,which accords with the actual situation.(7)using displacement results of numerical simulation of2#monitoring hole are compared with monitoring results of2#monitoring hole,the calculated value and the monitoring value of almost the same change trend,it shows that selected model and calculation method by FLAC3D numerical simulation calculation is reasonable.