The Experimental Study And Numerical Simulation Of Application Of Foamed Light Soil In High-filled Culverts

With our country's infrastructure getting consummately,the construction of highway is also constantly advance to the northwest region.Thus,by influence of the complex topography and physiognomy in northwest,more and more high-filled culverts t is gradually emerging.Culverts,as one of the important infrastructures of highway,its design,construction and maintenance have the vital significance.However,for such a long time,a wide range of high-filled culvert destruction have become a big problem,which influences the quality of highway construction in northwest China.Many researchers have concluded through the calculation and experiment analysis,the main reason why the destruction of the high-filled produces is the concentration of vertical stress on the top of culvert,which caused by additional stress,which differential settlement existing the top and side soil of culvert leads to.So how to solve or reduce the differential settlement existing the top and side soil of culvert properly,restrain the produce of additional stress and cut the probability of the destruction has an important significance.Based on the experimental analysis and the numerical simulation calculation,a new type of light materials,foam-lightweight soil is studied.Considering the advantage of its characteristics,such as,light,self-hardening,low flexibility,low cost,easy construction,without compaction,and while the age meeting,getting into the independent status and so on,plans of reducing the load on high-filled culverts are researched.The main research contents are following:a.Combining the features of high-filled culvert diseases,factors affecting the destruction and the mechanism of action are analyzed,and the light materials,foamlightweight soil is determined to be used for backfill to reduce the load.In terms of the characteristics of foam-lightweight soil,it will be filled in the side of the culvert.In this way,it not only can solve the problem,the concentration of vertical stress on the top and both sides of culvert,but also reduce the problems caused by inadequate compaction?b.The effect caused by the physical and mechanical parameters of filling on differential settlement existing the top and side soil of culvert,and the concentration of vertical stress on the top of culvert,is analyzed by numerical simulation.And how the different mechanical parameters influence is confirmed through the orthogonal experiment design method and range analysis method.The results show that the main factors are Deformation modulus and Poisson ratio,which are the main basis for choosing the material.c.According to the different uses of the foam-lightweight soil,different materials are chosen.In order to improve the test materials performance,a small amount of mineral is mixed with the traditional mixture made up with foam,cement,and fly ash.The orthogonal experiment design method is used to study the effect on the strength of foam-lightweight soil and mechanical parameters,caused by the consumption of the different materials.And the best mixture ratio is get.Among them,the water cement ratio and dosage of foam have a greater influence on the compressive strength and internal friction Angle of soil.d.The finite element analysis software,Midas is used for numerical simulation about variety of backfill schemes of foam-lightweight soil,and construct the effect on load reduction of the different shape and height from differential settlement,the vertical stress and the lateral stress.After all,the best plan is get.