Boya Highway Resign Research Of Inner Mongolia In Severe Seasonal Frozen Earth Area

This paper take highway design of seasonal frozen earth area in Inner Mongolia asbackground,focus on freezing expansion internal mechanism of frozen earth roadbed, analysisand study the highway design principle,main disease and prevention measure of seasonal frozenearth region.for engineering background, from seasonal frozen earth roadbed freezing expansioninternal mechanism, roadbed freezing depth calculation theory of the seasonal severe permafrostregion of highway design principle, general and prevention measures of main disease researchand analysis. In this project design process, according to the project of the route through badgeological sections in different roadbed, using different scheme to the treatment of frozen soilsubgrade, this paper gives the main conclusions as followed:1, According to the surface in permafrost within3.0meters frozen section, using all WaChupermafrost clay, change fill in the gravel, and then heavy road roller grinding, in order toeliminate foundation settlement after work to improve the stability and, at the same time, thebottom of the subgrade0.5meters laid a layer of geogrid, in order to enhance the overallstability of roadbed, on both sides of the subgrade set2meters wide,1m high waterproof spats.2, In the surface for a belt of3.0meters tall, roadbed fill in beyond the critical height withthe frozen ground frozen section, remove3meters of less than a belt of clay change fill,consider the location of underground water level is higher, change all fill in the gravel not easycompaction, in addition, PiShi mountain is the temperature of gravel, in order to improve thestability of roadbed, using the surface fill freestone cast,35cm above the surface filling thegravel+15cm not screening gravel processing measure, to fill in after work with heavy roadagain run rolling, in order to eliminate foundation settlement after work and improve thestability, and in not screening at the top of the gravel every0.2m laid a layer of geogrid, consistsof four layers of layer2only in roadbeds side slope2meters of less than, enhance the stabilityof the slope, TongPu layer2, in order to enhance the overall stability of roadbed.3,When permafrost in the surface outside,3.0meters high roadbed banquette less than the critical height with the frozen ground frozen section, first step，taking sameness measure asprevious, and at the same time in the roadbed surface50cm in a layer of5cmXPS board laidthe temperature. The temperature of density board XPS is not more than40kg/m3, compressivestrength not less than250kpa, coefficient of thermal conductivity is not more than0.028W/mk,bibulous rate is not more than1.5%, the vapor permeability coefficient is not more than2.0ng/M.S.P a, dimension stability coefficient is not more than1.0.4,seasonal frozen earth area of Inner Mongolia with a highway on the study design, in viewof the route after the adverse geological sections of the different conditions, seven points in theform of roadbed section typical design, and used the grit to fill in, throwing fill freestone, laidgrille and XPS board the temperature and other methods to special to the treatment of roadbed.5,the main road, communication on the overpass ramp, the service area ramp pavement andbridge deck pavement pavement structure design of the study. Given the pavement structure type,gravel graded requirements, material source and quality requirements, etc.