The Laboratory Experimental Study On The Engineering Performance Of Modified Raw Soil Material

The raw soil was applied in relatively early as building materials.A large amount of raw soil buildings are distributed in the central and western regions in our country.Raw soil buildings have many advantages of taking conveniently,simple construction technology,low cost,good artificial performance,save resources,protecting the environment,etc.In addition,some fields,such as foundation treatment,foundation pit backfill,roadbed filling,etc,have become extremely strict for performance of raw soil materials.But,the unmodified raw soil material has adverse engineering properties of low strength,poor water stability.The adverse engineering properties affect the popularization and application of raw soil material.Thus the study on the modified raw soil material is particularly important.This paper takes silty soil and loess as examples in Handan area,compares engineering properties of various modified soils as roadbed filling and guides the construction of Handan's soil improvement area on the bases of the indexes of physical and mechanical properties on various types of improved soil.First,this paper,studies soil improvement methods at home and abroad,familiars with the mechanism of various improvement plan and puts forward the suitable improvement plan in Handan area.Then,takes studies of indoor test,including the physical and mechanical properties of the raw soil,(liquid and plastic limit,compaction test,shear test,unconfined compression strength test)and scanning electron microscopy(SEM)test.Finally,this paper analyses characteristics of all kinds of improved solution and gets the best plan of raw soil improvement in Handan area.This paper,through a series of indoor experiments,gets the parameters of physical and mechanical properties of different improvement plans.The strength formation mechanism of all kinds of improved soils are observed by scanning electron microscope.Ultimately this paper gets the best plan for the Handan area is the mix of lime-fly ash and polypropylene fiber.The best proportion of modified silty soil is lime4%,fly ash 8% and polypropylene fiber 1.5%.The best proportion of modified loess is lime 4%,fly ash 10% and polypropylene fiber 1.8%.