Problems Associated with Railroads on Shrink-Swell Soils

Natural soils in Texas are dominated by expansive soils. These soils are characterized by significant expansions and contractions when they are subjected to wetting and drying processes, respectively. Railroads on expansive soils are subjected to huge solicitations associated with the volume changes of the soil, generally leading to unacceptable uneven settlements. Relative movements of railroads constructed on this type of soil can also be related to progressive shear failure, and long term consolidation and creep. The mechanisms behind the observed railroads problems on expansive soils, and the associated (possible) remedial solutions, are still unclear. A site in Texas has been recently selected to study in detail the aforementioned problems. In this paper we discuss the typical geomechanical problems associated with railroads in Texas and some possible solutions. We also present the test site selected to study this problem.