| Rigid retaining wall is a kind of retaining structure widely used in engineering.The calculation of earth pressure behind the wall is the key link in the design of retaining wall.In the existing calculation methods of clay soil pressure,the influence of soil arching effect is considered,but the interlayer shear stress caused by principal stress deflection is ignored in the calculation model.Therefore,based on the stress-Moire circle of active and dynamic clay,the relationship between the radial stress and strain of the soil behind the wall is assumed to be hyperbolic,and the relationship between the strength parameters of the soil and the displacement is deduced.Based on stress state of clayey soil is the interlaminar shear stress calculation formula is deduced,the interlaminar shear stress into the thin layer element method calculation model,earth pressure intensity given by using numerical integration,the point of resultant force and resultant force numerical format,with independent design model test and model test results of multiple sets of documents and materials confirmed the advantages of this solution.Finally,the sensitivity analysis of soil strength parameters and main design parameters is carried out,and the results are as follows:(1)The active earth pressure decreases with the increase of wall displacement ratioη,internal friction angleφ,cohesion c and cohesion c_w between wall and soil.It increases with the increase of filling surface dip angleε;With the increase of the friction angleδ,the active earth pressure at the upper part of the wall increases and the active earth pressure at the lower part of the wall decreases.With the increase of the back angleα,the active earth pressure on the upper part of the wall decreases slightly,while the active earth pressure on the lower part of the wall increases greatly.With the increase ofη,φ,δand c_w,the active earth pressure combined force increased gradually.With the increase of c,it firstly decreases and then gradually increases,and the initial decrease decreases with the increase of c_w.With the increase ofαandε,the influence of the former is obvious,while that of the latter is weak.(2)The passive earth pressure increases with the increase ofη,φ,c,c_w andε.Gradually decreases with the increase ofα;With the increase ofδ,the passive earth pressure at the upper part of the wall decreases and the passive earth pressure at the lower part increases.With the increase ofη,δandφ,the active point of passive earth pressure decreases gradually.With the increase of c_w,it is basically unchanged and only slightly decreased.With the increase of c,it first increases and then decreases gradually.It gradually increases with the increase ofα,but the overall amplitude is not obvious.With the increase ofε,it gradually decreases and tends to be stable.(3)Interlayer shear stress has a great influence on both the non-ultimate active earth pressure and the non-ultimate passive earth pressure,which increases the earth pressure on the upper part of the wall and decreases the earth pressure on the lower part of the wall.Therefore,considering the effect of interlayer shear stress,the position of the combined force of earth pressure increases to a certain extent compared with the soil arching effect,which is more consistent with the model test results.In addition,the change ofδandαmakes the distribution of earth pressure in the upper and lower parts of the wall show different change rules,because the change of the two greatly affects the interlayer shear stress. |
