Construction of Correlation between Basic Soil Properties and Deformation Modulus of Trackbed Soils Based on Laboratory and Field Mechanical Tests

Abstract

The soils used as trackbed in Korea are selected using USCS utilizing basic soil properties such as Grain Size Distribution(GSD), % passing of #200 sieve (P 200 ), % passing of #4 sieve (P 4 ), Coefficient of uniformity (C u ), and Coefficient of curvature (C c ). Degree of compaction of the soils adapted in the code by KR should be evaluated by maximum dry density (γ d-max ) and deformation modulus E v2 . The most important influencing factor that is critical to stability and deformation of the compacted soils used as trackbed is stiffness. Thus, it is necessary to construct a correlation between the modulus and the basic soil properties of trackbed soil in order to redefine a new soil classification system adaptable only to railway construction. To construct the relationship, basic soil test data is collected as a database, including GSD, maximum dry unit weight (γ d-max ), OMC, P 200 , P 4 , C u , C c , etc.; deformation modulus E v2 and E vd are obtained independently by performing a Repeated Plated Bearing Test (RPBT) and Light Weight Deflectometer Test (LWDT) for ten different railway construction sites. A linear regression analysis is performed using SPSS to obtain the relationship between the basic soil properties and the deformation modulus E v2 and E v . Based on the constructed relationship and the various obtained mechanical test data, a new soil classification system will be proposed later as a guideline for the design and construction of trackbed foundation in Korea.