Model Test And Analytical Research On The Active Earth Pressure Acting On A Rigid Retaining Wall

Although embankment retaining wall is often used in widening embankment,the research on the influence of differential settlement on earth pressure of embankment retaining wall is insufficient.It can only be calculated according to new embankment retaining wall in design,which will bring potential risks to engineering construction.In this paper,the model test method is used to study this problem.There are many factors affecting the earth pressure of retaining wall,and the actual distribution law is complex.There are many deviations from the results of Rankine or Coulomb's earth pressure theory analysis.In this paper,the formula for calculating the active earth pressure considering the influence of the small principal stress arch behind the wall is deduced by using the theoretical method,which can be used to analyze the related problems.The main work are as follows:(1)The model box which can realize differential settlement of fill and displacement modes of wall is used to test.The displacement quantity of retaining wall when the limit state of soil is reached under three basic displacement modes,namely,rotation around foot(RB mode),translation(T mode)and rotation around wall top(RT mode),is obtained when considering differential settlement.(2)The influence of differential settlement and displacement modes of retaining wall on the distribution of active earth pressure under three basic displacement modes(RB mode,T mode and RT mode)is studied by model test,and the results are compared with Coulomb's theoretical calculation values,which provides a theoretical reference for the design of widened embankment retaining wall.(3)In the case of undifferentiated settlement,based on the horizontal layer analysis method,the formula for calculating the active earth pressure of cohesionless soil considering the effect of "small principal stress arch" behind the wall is derived.Compared with Coulomb's earth pressure theory,the calculated results of the formula in this paper are more consistent with the model test results.(4)Through theoretical research,the stress state of the backfill and the shape of the small principal stress arch considering the friction between the backwall and the filling are analyzed.According to the derived formula for calculating the active earth pressure,the variation law of the coefficient of active earth pressure with the internal friction angle and the friction angle of the wall and the variation law of the resultant earth pressure force,resultant action point and resultant moment with the internal friction angle of the filling are calculated.