Analysis and specifications of filtration of surface runoff from railway track ballast section

Summary

Rail transport facilities are fixed structures that produce continuous impact on the environment. The main facilities – pollution sources among rail transport facilities are railway stations. In most cases polluted runoff from railway station tracks generated mainly as a result of atmospheric precipitations leaks through the surface relief, infiltrates into the subsurface, penetrates deeply and drains with underground water into the nearest water bodies. The processes of surface runoff filtration through multilayer porous media that are taking place in the ballast section of the railway track have been analyzed and specified. Possible hypotheses of liquid behavior and properties in multilayer porous media, in particular of the liquid on the surface of ballast section of the railway track accumulated as a result of atmospheric precipitations; steady and unsteady liquid seepage into the railway ballast depth; dissipation of oil product spills on railway tracks are presented.

Key words

filtration , oil products , surface runoff , train track , ballast section

Dynamics of the infiltration of liquid pollution into the ballast section of a railway track within the framework of Forchheimer’s law

Summary

The dynamics of a liquid layer infiltration into porous soil induced by the gravitational forces is considered within the framework of the two-term filtration law (Forchheimer’s filtration law). Simple formulas are obtained for the time dependence of the height of the liquid layer on the soil and the time of complete infiltration of liquid into the soil on the filtration coefficient and porosity of the soil. It is shown that the total infiltration time is directly proportional to the height of the initial liquid layer on the ground. Calculations of the time and average speed of complete infiltration for typical soils were carried out.

Key words

infiltration , ballast section , liquid pollution , body of ballast , porous soil , infiltration time , porosity , filtration of coefficient

Indirect method of determining pollution concentrations of train track surface runoff

Summary

The classification (categorization) of the train track and railway station ballast section pollution density has been developed and approbated. Each category of train track pollution density is specified and the criteria of the space interval attribution to a pollution density category are presented. The pollution concentration of train track surface runoff as a function of the ballast section pollution density is determined.

Key words

suspended substances , oil products , surface runoff , train track , ballast section , pollution density classification , pollution density category