Sand dunes control methods to prevent the crisis on the Iran railway lines

Moving Sands phenomenon, as a natural hazard in desert areas, has always imposed a lot of damages to the transportation sector; so that 5.5% of all rail lines are located in the sandy areas of Iran. On the other hand, the need of crossing railway lines in the deserts and sand dunes created numerous problems for railways, including the sudden deviation of trains from the railway, numerous blockings, pavement stiffness, wearing devices connecting to line, decreasing immunity and the high costs of maintenance and repair has made it necessary to provide and implement strategies to stabilization sand dunes of the desert railway.
Method and Findings: Research in this context has been done by reviewing the literature and field studies attending the railway lines of East Railway Department.
Findings: The solutions offered on the problem of fixation of flowing sands before reaching the rails including vegetation, trench and embankment construction, sands traps and building walls as well as the problem of prevention of entry of sands on tracks such as humped slab track and tunnel have been introduced and discussed in the present research.
It can be seen from field observations in East Railway Department that several solutions like planting and slipper walls have been used in the Iranian railway; however, the problem has not been solved completely since the related limitations have not been considered. In some cases, these solutions were useful for a while, but after that, sands have passes the barriers and reached the rail. In fact, conditions and characteristics of the rail track are such that administrative procedures or methods of sand dune stabilization in the country's rail must be according to Iran's climate, geographical conditions, geomorphology, and soil erosion. Since each solution has their own limitations, the best way is to use the combination of two or more solutions. It should be noted that track and region conditions where tracks have been constructed must be studied in order the use the best combination.