Study On The Ground Treatment Technology Of The 315 Route Of The Provincial Highway To The Nileke Highway

Collapsible soil refers to the soil under the action of the self-weight of the overlying soil layer,or under the combined action of the self-weight stress and additional stress,due to the structural damage of the soil after water immersion and significant additional deformation.Loess is a special deposit of quaternary,i.e.a clay mainly composed of silt,small natural moisture content,porous,yellow,brown yellow and calcareous.According to the data statistics,35 % of the main highway subgrade in Yili Kazakh autonomous prefecture of Xinjiang Uygur autonomous region is mainly loess soil,loess soil collapsibility characteristics make the road frequent uneven collapsibility,which brings great security risks to road traffic.Loess in northeast China,northwest China,central China and east China is mostly collapsible,and the building(structure)is built on collapsible soil,often appear related to the damage of collapsible,the collapsible characteristics of loess soil is the main cause of subgrade damage.Therefore,the research and treatment of collapsible loess occupies a special position in the engineering field.The causes,chemical and physical properties,distribution range and strength of collapsible soils are becoming more and more well known.There are many methods to treat collapsible soil.according to different treatment horizons,collapsible soil treatment can be divided into surface treatment,subsurface shallow treatment and subsurface deep treatment.According to the different treatment methods,collapsible soil treatment can be divided into: surcharge preloading,reinforced embankment,back pressure protection,granular bedding,riprap siltation,dynamic compaction displacement,consolidation and drainage methods.In the construction of collapsible soil section,people often pay attention to what kind of treatment method can be more cost-effective to achieve the treatment effect.At present,most of the engineering construction adopts the following methods: dynamic compaction,replacement of gravel cushion,impact rolling,compaction pile method,etc.In this paper,the physical and mechanical properties,subgrade treatment scheme and effect,and construction technology of the collapsible soil in Yili area are evaluated according to the highway construction situation in the loess area of Yili prefecture,Xinjiang,relying on the highway construction project from shengdao 315 line bee farm to nileke.Through field test,the construction technology and foundation treatment effect of dynamic compaction,replacement of gravel cushion,impact rolling and compaction pile are systematically studied.Through the test of the above treatment methods,we think that the foundation treatment methods such as dynamic compaction,replacement of gravel cushion,impact rolling and compaction pile are also applicable to the treatment of collapsible soil in Ili area.But it should also be noted that the different collapsible soil foundation treatment plan has its own characteristics and scope of application,so in the construction should be flexible to master,so that the best treatment effect,the most economic and effective.Finally,several treatment methods of collapsible soil foundation are summarized and prospected.