Sublevel scheme is a major type of underground mining. At each sublevel, mine is blasted to form a silo, so that ore can be extracted from the bottom outlet of the silo. Due to the extraction, ground surface will have some significant subsidence, which can influence nearby infrastructure. To avoid this impact, a filling material might be stopped from upper sublevel during the extraction. This additional load creates spatial constraints for the granular flow and might stimulate the arching of this granular material. The research employs Discrete Element Method to simulate granular flow in silos under general vertical loadings. Particles are generated by Voronoi tessellation at a given porosity. The sample is shaken lightly so that particles can achieve a more random position and neutral contact. After that, they are released under gravity to form a granular flow. A parameter study is undertaken to find the condition of arching. A force is assigned to a top plane to simulate a top load, which increase stresses in force chains. The research draws out the influence of the geometry and top loads on arching probability in a silo.