Study On The Influence Of Widening Embankment On The Stability Of Existing Embankment

In order to analyze the influence of widening embankment on the stability of existing embankment,understand the mechanism of widening embankment with different compactness on the change trend of existing embankment,and explore the deformation development trend of widening embankment in road operation.Based on the disease treatment project of K0 + 460 ～ K0 + 600 section of Meilin Road,this paper carries out on-site detection on the disease section,and understands the physical and mechanical properties of embankment fill through indoor tests.Midas GTS software is used for finite element calculation to analyze the influence of widening embankment with different compactness on the overall stability of embankment,and to clarify the deformation trend of widening embankment under different driving conditions.The stability of the existing embankment is analyzed by the finite element method.The conclusions are as follows:(1)The uneven coefficient and curvature coefficient are 3.7 and 0.5,respectively;According to the limit water content test and permeability test,the liquid limit Lω and plastic limit Lω of the fill are 35.6% and 20.18%,respectively.The filling of widened embankment does not meet the requirements of embankment filling materials,and the disease development of this section is closely related to the filling materials.(2)With the increase of compactness,the cohesion changes in a curve,the internal friction angle decreases as a whole,and the peak stress and confining pressure of fill with different compactness change linearly.When the same sample contains two compactness,the cohesion increases with the increase of compaction degree,and the internal friction angle decreases with the increase of compaction degree,but it has no correlation with the cohesion and internal friction angle of single compaction specimen.With the increase of confining pressure,the plastic strain of fill has different changing trend.When the amplitude condition is different,the plastic strain has obvious stage distribution.When the vibration frequency is different,the plastic strain vibration deformation curve is different.(3)After the embankment is widened,the stability coefficient is positively related to the compactness of the widened embankment fill.When the compactness of the widened embankment K=94%,the stability coefficient of the embankment is the largest.The embankment is widened by filling with different compactness,and the damage surface of the embankment is different.The magnitude and location of the maximum stress of the embankment will change with the increase of the compactness of the widened embankment filling.(4)In the parking load,the maximum stress of the embankment increases with the increase of the compactness of the widened embankment,and the displacement deformation of the embankment decreases with the increase of the compactness.When the compactness K of the widened embankment is greater than 90%,a sliding surface with the same displacement appears on the widened embankment,which is easy to cause the embankment to slide from the sliding surface.In the traffic load,the displacement of embankment decreases with the increase of compactness,and its stress changes with compactness in a curve.Under the condition of maximum design speed,the maximum stress of embankment is about 1.8times of the traffic load.(5)Combined with the monitoring data and numerical simulation results,the disease development of widened embankment shoulder is related to the consolidation settlement of soil itself,and the crack disease of road centerline is related to the compaction of widened embankment.Due to the combined action of traffic load and consolidation settlement of widened embankment,different types of road diseases appear in this section of road.In order to improve the stability coefficient of embankment,the treatment of shoulder should meet the requirements of normal use.