Stability And Dynamic Response Analysis Of High Fill Embankment Slopes On Freeways

The SJ4 section of Mengxing Jiangcheng Lvchun Expressway is located in a complex and varied terrain and geological environment in mountainous areas.Due to multiple factors such as external additional loads and soil properties,the stability of the high fill roadbed slope is reduced,and engineering safety accidents are prone to occur.At the same time,under the action of vehicle loads on highways,the stability of slopes becomes more significant.In order to study the dynamic response and stability of high fill embankment slopes under vehicle loads,firstly,ABAQUS software and its secondary program were used to develop a finite element model of high fill embankment slopes.The dynamic response laws of high fill embankment slopes under different vehicle speeds and load conditions were systematically analyzed.Then,considering the presence of soft layers on some slopes in the engineering section,stability analysis is needed to ensure safe driving of vehicles.Based on the stability analysis results,anti-slide piles are required to reinforce the slope.Finally,multiple working condition models were established for different anti slip pile reinforcement pile positions,pile lengths,and pile spacing to obtain the optimal reinforcement method.The analysis results indicate that:1.At a driving speed of 100km/h,the vibration frequency of a four axle truck is relatively close to the natural frequency of the embankment in this section,and all dynamic responses are strongly reflected.The maximum vertical stress fluctuates around an intermediate value over time.The maximum vertical displacement over time occurs in the third to last analysis step and exhibits a significant peak,where the impact of vehicle load on the embankment slope is greatest.2.Using the displacement inflection point,calculation non convergence point,and slope plastic continuity as the evaluation criteria for slope instability,the safety factor F_s=1.169778.Slope failure starts at the foot of the slope,and a plastic yield point is formed at the foot of the slope.At the increment step t=0.3299,the phenomenon of plastic zone penetration occurs.The plastic penetration zone of the slope is located in the lower part of the middle of the slope,belonging to a curved sliding surface,which is in line with the actual situation of the project.The horizontal displacement of the slope is mainly concentrated in the upper part of the sliding surface along the slope toe,and the vertical displacement changes in a stepped pattern from left to right,mainly concentrated in the approximate triangular area below the slope top.3.The first level slope platform is the optimal reinforcement pile position,the 28m anti-skid pile length is the optimal reinforcement pile length,and the 4m anti-skid pile spacing is the optimal pile spacing.Under this reinforcement method,the stability of the slope has been significantly improved.The maximum horizontal displacement of the slope decreased by 5.89cm compared to before reinforcement.The maximum vertical displacement decreased by 7.23cm.The stability coefficient F_s of the slope is 1.433396.The maximum displacement of the anti-slide pile is 0.23cm.Due to significant plastic deformation occurring at the top,middle,and bottom positions of the three reinforced pile positions,the plastic penetration surface undergoes significant displacement.In summary,by analyzing the dynamic response and stability of high fill embankment slopes,the dynamic response law of the slope under moving loads was obtained,and the most unfavorable situation of the slope was determined.The law of slope instability has been obtained,and the optimal method of anti-slide pile reinforcement has been determined.