Upper Bound Analysis Of Active Earth Pressure For Flexible Reinforced Gravity Wall

As an emerging composite retaining wall structure,flexible reinforced gravity wall has limited theoretical research and engineering applications,and the design and construction lack normative guidance.In this paper,under the influence of B/H factors of retaining wall length-height ratio,four failure modes,such as linear sliding mode,wedge sliding mode,improved Sokolov mode and Gu Weici test model,were adopted,and the calculation formula of flexible reinforced gravity wall active earth pressure combined force and action point and strength distribution suitable for inclined wall and inclined fill surface containing uniform cloth load was derived by using the limit analysis upper limit method.Using Matlab’s SQP nonlinear programming solution tool,the influence of retaining wall height H,wall backcamp angle α,fill inclination β,post-wall fill bulk γ,cohesion c and internal friction angle φ,wall-soil interface friction angle δ,fill surface uniform overload q,reinforcement limit tensile T,reinforcement arrangement spacing and other parameters on the horizontal flexible reinforced gravity wall after the fill failure angle,active soil pressure and strength distribution were analyzed.The main research results are as follows:(1)In the four failure modes,compared with increasing the ultimate tensile force of the reinforcement T and reducing the horizontal arrangement spacing of the reinforcement,the appropriate reduction of the vertical arrangement spacing of the reinforcement can more effectively reduce the active earth pressure behind the wall.Moreover,the spacing of the reinforcement arrangement of the flexible reinforced gravity wall should not be too small or too large;according to the results of the study,this paper believes that the spacing and optimization design value of the reinforcement arrangement should be 0.4～0.6m.(2)In the linear sliding mode and wedge sliding mode,the active earth pressure intensity is distributed in a straight line along the wall height H,and under the modified Sokolov mode and the Gu Wei ci test model,the active earth pressure intensity is distributed along the wall height H in a convex curve.Under the same conditions,the active earth pressure behind the wall obtained by using the linear sliding mode is the largest,followed by the wedge sliding mode,the Gu Weici experimental model is small,and the modified Sokolov mode is the smallest.And as the length-height ratio of the retaining wall increases to B/H,the calculation results of the latter three destruction modes gradually increase to and close to the linear sliding mode calculation results.(3)The reliability of the theoretical formula is verified by comparing and analyzing the calculated value of the theoretical formula of this paper with the engineering example,numerical simulation,predecessor theoretical formula and indoor test results.Since the more comprehensive design parameters and conditions are considered in the derivation of the formula,the proposed formula has a large scope of application,and the relevant results have certain theoretical significance and engineering value.