The Study Of Stability Of Soil Slope Under Stream Erosion

The collapse natural soil bank,which caused by the long-term erosion,is not uncommon.The erosion of slope has been one of the problems that engineers and researchers care about all the time.In the Heilongjiang Province,due to the large number of border rivers,the erosion of the river bank of China has great influence to the people's property and the normal social life.Based on the summary of the enriched and developed limit equilibrium method,the finite difference strength reduction method(Flac3D software)and finite element method(Geo-studio software)have been applied on analyze of the soil slope stability,meanwhile,the sensitivity of different factors on the slope has been discussed.In the study of the erosion of water flow,widening and scouring depth calculation model,Songhua River hydrologic geological data in 2008-2010 has been used in erosion simulation.Using finite element analysis method and Geo-studio software,which based on soil slope steady seepage and internal stress and strain conditions in studying the slope stability,in consideration of water level rising and falling.The main objective of our study has been to obtain some results as follows:(1)The river bank soil condition is the internal factor of the bank collapse,and the flow condition is the external factor,which is the conclusive factor.The internal factors sensitivity analysis proves that the sensitivity of slope angle is 0.785,the internal friction angle is 0.561,cohesion is 0.417,density is 0.409,the slope angle influence the slope stability most,the internal friction angle and cohesion are medium,and the soil bulk density has the lowest influence.(2)The stability of a generalized slope is calculated.It is found that the safety factor calculated by the finite element method and the strength reduction method are greater than the limit equilibrium method.Compared with the limit equilibrium method,the finite element method and the finite difference method do not need to assume the stress of the landslide body,which leads the calculation resultto be more accurate.(3)River widening width and scouring depth,which calculated by Songhua River 2008-2010 years relevant hydrogeological data and show that the erosion is violent in flood period,and small in non flood period.The horizontal and vertical erosion rate in the flood season of 2010 reached 3.4 cm/d and 3.1 cm/d.The depth of erosion is affected by the variation of river sediment concentration,which is less affected by water depth and river width.The transverse widening of the river is more obvious by the change of the water depth and the width of the river channel,which is less affected by the sediment concentration.(4)As the stability of the water level increases gradually,the stability of the water level decreases gradually.Riverbank is easily to collapse during the declining.The safety factor of the bank slope decreases exponentially with the decrease of the water level.The faster the water level is reduced,the worse the slope stability,the faster reach the critical instability state.T With the foot of the foot slowly washed back,stress concentration occurs at bank toe,the maximum deformation gradually increased,and the stability gradually reduced.(5)Renault pad structure,concrete hinge block structure,prefabricated concrete slab combined with insulation structure lining and other revetment measures should be in harmony with the reasonable protection of the shore form.According to local conditions,giving full play to the characteristics of materials to reduce water erosion,frost heaving damage and the freeze-thaw cycle damage in the seasonal frozen river banks.