Huadian Changsha Power Plant Railway Expansion Pilot Study Of The Earth Embankment Lime Improved

In this dissertation, the danger brought from the ground base caused by expansive soil to the construction is introduced. Main properties of expansive soil are analysed, the problems exist in constructing base with expansive soil are discussed. Laboratory experiments have been done on representative samples in this thesis. Physical and mechanical parameters such as natural moisture content, liquid limit, plastic limit, free swelling ratio are obtained. When lime is used as stabilized agent to improved the properties of expansive soil, compaction tests, dynamic load test, none pressure expansion tests, swelling force test, consolidation test, microcosmic test and non-confined compression tests of diferent periods have been made. The engineering properties of improved expansive soil are studied. The detailed contents are as following:(1) Expatiate of the main engineering properties of expansive soil and mechanism of expansive soil improved by lime.(2) Research the rules of change about optimum water content. Maximum dry density, strength, none pressure expansion, swelling force and elasticity modulus of improved expansive soil adapted to different times of cycle loading.(3) Take the photos of samples of different plain soil and improved expansive soil by using the optical microstructure experiment system, get the relation between degree of compaction, period and area ratio of pore (grain) of soil mass, orientation degree, distribution, dimension. Show some rules of change of minuteness structure of improved expansive soil.(4) Research the rules of change about the compression modulus of plain soil and improved expansive soil on diferent conditions. Meanwhile calculate the setlement of roadbed to predict the later settlement.(5) Use the FLAC 2D software to analysis the deformation rule of expansive soil roadbed.(6) Puting forward some advices aiming at the unsaved problems in road foundation of railway on the basis of theory combining with practice and reading lots of data about expansive soil in the world.