Standard for Rock and Soil Classification of Railway Engineering unifies the criteria for rock and soil classification of railway engineering and plays the supporting role as a basic standard.This Standard is prepared based on revisions made to Code for Rock and Soil， Classification of Railway Engineering （TB 10077-2001） ， geotechnical experience of China railway in recent years and relevant Chinese and foreign research achievements.
　　This Standard consists of 4 chapters， namely General Provisions， Terms and Symbols， Classification of Rock and Rock Mass， and Classification of Soil.
　　The main revisions are as follows：
　　1.The basic principles for classification of rock， rock mass and soil are specified.
　　2.The contents on salinastone， saline rock and basic quality classification of rock mass are added.
　　3.The classification of rock formation thickness is adjusted.
　　4.The particle size grouping of soil and classification of gravel are revised.
　　5.The grading of clay with medium compressibility is refined.
　　6.The quantitative judgment indexes of compactness of gravel are added.
　　7.Criteria are added for the vane test and flat dilatometer test of soft soil.
　　8.The classification of sensitivity of soft soil and the judgment indexes of static cone penetration test for the soft soil are revised.
　　9.The criteria of saline soil are revised.
　　10.The seasonally frozen soil and the frost-heaving grading of seasonally thawed soil layer are added.