Research On Engineering Characteristics And Road Performance Of Expansive Soil In Central Anhui

Expansive soil is always a technical problem in geotechnical engineering field.The deformation behavior of expansive soil expanding with water while contracting without water and the characteristics of expansive soil side slope strength deterioration under water are exerting a powerful destructive influence over the expansive soil area.They destroy industrial and civil building,water conservancy,railways,highways and other engineering construction and engineering operation of the expansive soil area.The study of the engineering characteristics and control technology of the expansive soil has played an important part in theoretical significance and engineering application value.Through the means of laboratory experiment,field test,field observation and the combination of theoretical analysis and numerical simulation,we make a comprehensive research on the engineering characteristics of the expansive soil.And then we discuss analysis method and the treatment countermeasures in order to provide a scientific basis for engineering construction in expansive soil area and promote the development of expansive soil subject and unsaturated soil mechanics _Th^subject._{is major research content with the results as follows:}1.Resrearch the distribution and characteristic of expansive soil along highway in area and do a deep discuss about swell-shrink principle and properties indicator of expansive soil.We can identify expansive soil according to five indexes,water limit,plastics index,free swelling ratio and<0.005mm particle concentration swell-shrink ratio.These five indexes reflect the swell-shrink principle and characteristics of expansive soil.We create a new method of distinguishing and classify the expansive soil--fuzzy comprehensive evaluation on expansive soil.Through a large number of experiments,we propose a classification criterion on the expansive soil in central Anhui.2.Systematically we carried out experimental research on engineering characteristics of expansive soil in central Anhui,and expound the change law of compaction characteristics,swell-shrink characteristics,strength and deformation characteristics of expansive soil and influence factor it can make.On that basis,we discuss that whether expansive soil can be used as subgrade filling in engineering,therefore we have a deeper understanding of engineering characteristics of expansive soil.3.We carry out experimental research on Lime Modified.Expansive Soil in Central Anhui,analyze the change law of compaction characteristics,physics indexm,swell-shrink index and mechanics characteristics of modified soil under different ration systematically.On that basis,we make scheme on modified expansive soil in central Anhui and the standard of filling control.4.On the basis of those experimental studies,theoretical analysis and numerical simulation,we study the subgrade control of expansive soil and slope protection and calculate stability of side slope of embankment in allusion to different slope ratio,slope altitude,softened layer thickness,by means of a large number of experiments,we propose structure type of expansive soil embankment.We suggest layout drawing of the cross section of expansive soil embankment and of the cross section of the highway slope protection.