Centrifuge Model Test On The Soil Nailing High And Steep Loess Slope In Tunnel Myongdong

Centrifuge model test is a technique that is widely used in the research field of Civil Engineering. One of its most distinct advantages is that the process of deforming and being destroyed of the soil can be observed with prototype.At first, this thesis summarizes the developing history and the state-of-the-art in centrifuge model test and the soil nail and soil nailing slope , discusses the principle of the technique of the centrifuge model test .To discuss the feasibility of applying this technique into the soil nail and soil anchor support practice of engineering,this paper references the real project of the Lv Jiaya tunnel ,uses the geotechnical centrifuge of Southwest Jiaotong University,make two experimentation. Form the staged of the slope excavation and retaining, research the settlement of the slope and the deflection of the soil nail.The experimental results show that:1) the deformation profiles of soil nailing slope were different from those of general slope.2) Because the stiffness of the nails is larger than the soil, the deformation of the soil is restricted. The soil that is restricted, acting as retaining wall, decrease the deformation of the soil that is not restricte deffectively. The stress of the surface course and nails transfer diffusion,i.e. the surface course and nails transfer the excavating load to the soil that is restricted, so soil among more area take action, which slower the extend of the plastic area, and restrict the increase of the plastic deformation.3) The strain profiles of soil nailing slope is:The largest in the central of the soil nail, At both ends, gradually decreasing.4) The biggest strain of soil nailing in the central part of the slope,the smaller in the the other part.At last, this thesis points out some problems existing in the centrifuge model test technique and estimates the developing trend of this technique.