Abstract: According to the geological condition in Mengjiagang Iron mine, as well as railway, highway passing through the mining area, in order to maximize the resource recycling and ensure the transportation safety of upper railway, two mining schemes including the cemented filling method and room and pillar method were adopt in this paper. Mechanical parameters of rock mass were comprehensively determined based on rock macrostructure survey, sampling, rock mechanics test and engineering analogy. In addition, the software of Comsol Multiphysics was used to calculate the surface sedimentation height caused by the two different mining schemes. The numerical calculation results show that when using cemented filling mining method with the mix proportion scheme of “tailing + cement + fly ash + water”,  the sedimentation values of railway surface in the range of No. 5 and No. 6 exploration lines are all less than 30 mm, which meets the requirement of safety regulations, and will not affect the normal operation of railway on the surface. The validity of cemented filling method with tailings is verified well by later surface displacement monitoring results.

Key words: mining engineering, mining under railways；surface deformation；finite element analysis；subsidence monitoring