The Boxing Day tsunami in December 2004 devastated several South and Southeast Asian countries. In the Eastern and Southern coastal belt of Sri Lanka, the floodwaters caused unprecedented damage to infrastructure and over 40,000 fatalities. Widespread destruction included severe damage to many buildings and dislocation of several kilometres of rail tracks. Under excessive hydraulic gradients of waves, the geotechnical properties of surface soils up to a meter or more have been significantly altered. In this paper the relevant aspects of dwellings and rail tracks and reconstruction on devastated coastal soils are elucidated. Guidelines for reconstructing robust cost-effective foundations are discussed, based on the first author’s own experience. Revised ballast grading and enhanced track conditions are considered, including the benefits of increasing track confining pressure and the essential need for soft formation stabilisation. The use of geocomposites in achieving reduced track settlement, increased resilient modulus and decreased ballast degradation, is described.