Research On Filling Subgrade Technology With Extra Large Particle Size

According to the characteristics of the highway subgrade engineering in the mountainous area,it is difficult to directly fill the subgrade with extra large particle size fillers for tunnel slag and excavated stone.It is proposed to use the rockfill skeleton filling method to solve the key problem of using extra large particle size filler for roadbed filling.technical problem.The key core of the technology is to accumulate extra-sized particle size into high-strength skeleton rockfill structure with particle size classification,and then use liquefied soil technology to add and add additives along the waste soil source to form a rigid and coMPact rockfill.New subgrade of body structure.The rockfill structure subgrade engineering of this study has the advantages of high strength,good stability,rigid coMPaction,no filler compression,post-construction settlement,strong anti-crushing ability,etc.,which can avoid secondary crushing of extra-large particle size and reduce engineering.But also solve the problem of postconstruction settlement of high fill roadbed.The research relies on the construction of Yanchong Expressway,mainly researching the preliminary experiments and basic theories of this technology.The research contents and achievements mainly include the following aspects:(1)For the problem that the extra-large particle size is difficult to directly fill the roadbed,the extra-large particle size(60~150 cm diameter)filler is directly used for roadbed filling by the rockfill skeleton filling method,and the theoretical analysis and test of the consolidation of the rockfill body structure is carried out.Finally,the slurry and the filler are well cemented,and the extra large particle size filler can be directly used for roadbed filling.(2)Referring to the theory of "two-stage" filler-stacked rockfill structure,relevant tests were carried out to determine that the optimal gradation ratio is d1:d2=6,and the grading of the stacked rock mass structure can obtain smaller gaps.The rate can not only reduce the amount of liquefied soil slurry,but also meet the gap of the slurry to smoothly fill the rockfill structure.(3)Calculate and coMPare the actual "viscosity radius" of the viscous soil slurry "viscous flow radius" and the extra large particle size rock pores,and obtain the liquefaction when the liquefied soil slurry is completely filled with the extra large particle size rockfill structure.The minimum fluidity of the soil slurry;the liquefied soil slurry was prepared by the "orthogonal-comprehensive evaluation method",and the optimal blending ratio of the slurry was obtained;the different components and time were studied for the liquefied soil.The relationship between the fluidity of the slurry and the proposed requirements for the new slurry to be used within 30 minutes.(4)The Abaqus numerical simulation software was used to study the postconstruction deformation of the oversize rockfill structure subgrade,and coMPared with the results of the filled subgrade under the same working conditions.The results show that the super large particle size rockfill structure subgrade engineering property is excellent.In the fill roadbed,it has the characteristics of small settlement after construction and good stability.(5)Summarizing the characteristics of extra large particle size filling roadbed,the grouting process is used to fill and consolidate the extra large particle size roadbed of the rockfill method,optimize the construction process,and study the construction technology of the extra large particle size filling subgrade.