Experimental Study And Numerical Analysis Of 3D Soil Arching In Piled Reinforced Embankments

The work system of piled reinforced embankments mainly consists of embankment filling,horizontal reinforcing material,pile cap,rigid pile and foundation soil.Due to the existence of vertical and horizontal reinforcements at the same time,so piled reinforced embankments can effectively control the subgrade post-construction settlement,uneven settlement,deformation of roadbed lateral,satisfy the requirements of the stability and deformation of construction project.At the same time,it can accelerate the construction and shorten the construction period.Compared with common soft-base treatment,it has obvious economic and environmental benefits.At present,both home and abroad have also its widely used in soft soil foundation on the bridge connection or other special soil embankment project,the existing highway embankment widening engineering,new roads and railway embankment engineering,etcDue to the interaction and mutual influence between multiple parts of the pile bearing system,its working mechanism and characteristics are very complex.For 3D soil arching in piled reinforced embankments which due to stiffness difference of pile and soil,and tension membrane effect caused by geotextile tensile stress strain,there are many differences.Based on the above mentioned problems,this paper mainly carries out the following work and draws the corresponding conclusion,so willing to have a further understanding of the working characters of piled reinforced embankments.(1)I had summarized the research and development of the project,and comprehended the characteristics and applicability of all kinds of research methods and their conclusions.(2)The indoor model test of pile bearing type reinforced embankment was carried out,and the soil arching effect and the membrane effect were analyzed.The sedimentation rules of soft soil materials were analyzed by self-made sedimentation plate.And the influence of several factors was studied.The stress distribution in soil under the soil arching effect and the membrane effect were analyzed by embedding micro-soil pressure box.And the influence of several factors on the stress transfer in the soil was also studied.The experimental results of the stress reduction coefficient are compared with the theoretical calculation results.The stress deformation of geosynthetics was studied through the strain gauge on it.(3)For the sake of contrast verification with test results and supplementing the disadvantages of test,I established a three-dimensional numerical model based on finite element software ABAQUS.I further studied the traits of pile reinforced embankment through the model.The law of sedimentation and stress distribution in numerical simulation are consistent with the experimental results in many aspects.And through numerical calculation results of the model,I studied the soil arch height and the equal settlement.At the same time,I analyzed the influence of more related factors on the soil arch effect and the membrane effect.Through numerical simulation,the three-dimensional stress state and visual deformation of the reinforcement are obtained(4)Lastly,I compared the results of numerical simulation with the theoretical calculation methods based on the classical theory which have been proposed in recent years.Then,I analyzed existing differences and the cause of their differences.