Study On The Mechanical Properties Of Support Structure For Shallow Buried Aeolian Sand Tunnel Based On Vertical Jet Grouting Pile

In recent years,with the implementation of the national increase in infrastructure construction and investment of the western development strategy,the rapid development of highway traffic in Qinghai Province,But there is a large area of eolian sand cover in Qinghai Province,Exposed sandstone,shale,etc.This special geographical environment makes the tunnel become an important building type across the area.The special engineering properties of aeolian sand has brought many problems for highway tunnel design and construction.For example,the stability of the surrounding rock is poor,the deformation of surrounding rock is completed in short time after excavation,Support is not timely,it is likely to collapse.The paper relies on the project of Tuotushan tunnel which belongs to Qinghai province Chage highway,the aeolian sand tunnel adopts Pre-reinforcement processing of vertical jet grouting pile on the surface.In order to analyze shallow aeolian sand tunnel support structure stress and deformation characteristics of the surface vertical jet grouting pile reinforcement based on the shallow vertical jet grouting pile reinforcement,Field test is carried out t and the finite element method is used to analyze.The field test content includes the contact pressure between the surrounding rock and the primary lining,the axial force of the steel frame,the contact pressure between the primary lining and the secondary lining,and the stress and strain of the secondary lining concrete.The numerical simulation is carried out by using FLAC3 D finite element software to simulate the construction process of shallow buried aeolian sand tunnel.And The results of numerical simulation are compared with measured data,comprehensive error analysis of numerical simulation results and field data,from the common point of shallow aeolian sand tunnel supporting system deformation research,and to analyze the uncertain factors of both error.In order to obtain the characteristics of the supporting structure in the process of the construction of the core soil step method in the excavation of the annular excavation by the method of the vertical buried jet grouting pile.Based on the study of the wind tunnel in advance,the purpose of this paper is to provide reference and experience for similar tunnel engineering.