Study On Treatment Technology Of Bamboo Geo-grids Reinforcement At The Interface Of Filled Subgrade Of High And Steep Gullies In Loess Region

"Western China development" and "The Belt and Road" national strategies have been continuously advanced.A large number of transportation infrastructure projects have been constructed in the loess gully region.As there is a shortage of available land resources in this region,large-scale filling projects such as "ditch filling and land reclamation" are gradually increasing.However,this type of high fill project may cause excessive differential settlement between the fill and the undisturbed soil.This paper,aiming at the differential settlement of the interface between the fill and the original soil of the loess-filled subgrade in the high and steep gully area,the environmentally friendly reinforced material-bamboo reinforcement is used as the research object,relying on National highway 310 Luo Sanjie to Henan-Shaanxi border southward transfer project,and through lab experiment,theoretical analysis,numerical simulation and on-site monitoring,the numerical simulation,interface properties and control effects of the bamboo geo-grid are studied.And some suggestions on construction technology of bamboo geo-grid reinforcement of the loess-filled subgrade in the high and steep gully area are given.The main research contents are as follows:(1)Through lab mechanical performance research,the tensile strength parallel to grain,the shear resistance parallel to grain,the compression strength parallel to grain and the bending strength of the bamboo were obtained,and the relevant influencing factors were analyzed,and the mechanical feasibility of the bamboo reinforcement as a reinforced material was verified.And then,the relevant physical properties of the soil materials in the test section were tested,and the basic physical parameters of the soil materials were obtained.(2)Based on economy and durability,the applicability of the bamboo reinforcement grid project is analyzed,the anti-corrosion treatment technology is explained,and the on-site anti-corrosion treatment recommendations is put forward.Besides,the reinforcement mechanism and the force characteristics of the bamboo geogrid grille laying on the interface are analyzed,which provided a theoretical basis for the research and analysis of the interface properties and deformation control of reinforced soil.(3)Through large-scale direct shear tests,the characteristics of the interface between the bamboo geo-grid and the loess under different factors such as vertical stress,shear rate,grid type,grid spacing,and packing density were studied.The influence of different factors on the shear stress,shear displacement,and shear strength of the interface between the bamboo geo-grid and the loess was analyzed,the related mechanisms were discussed,and preliminary suggestions on the optimization of the bamboo geo-grid were given,and the relevant parameters of the numerical model reinforcement-soil interface are determined.(4)Through the finite element numerical simulation method,the law of stressstrain behaviors changes before and after reinforcement of loess-filled subgrade in high and steep gully region was studied,and the settlement control effect of different positions and spacings of the bamboo geo-grid was compared,and the optimization of the reinforcement of the bamboo geo-grid was proposed.Based on the actual project,the simulation data and the field data are compared,and the rationality and applicability of the model constructed in this paper are verified.The research results provide suggestions for the construction technology and optimization design of the bamboo geo-grid of the project.