Abstract: To reveal the mechanism of surface movement and deformation caused by water loss in thick unconsolidated confined aquifer during coal mining, based on specially designed experimental equipment, the water loss settlement experiment of unconsolidated confined aquifer was carried out, and the effect mechanism of confined water loss in unconsolidated layer to surface subsidence was analyzed. The results show that consolidation settlement of soil can be appeared due to water loss no matter with pressure or not, which is also the reason for consolidation and compression deformation of aquifer. Under the same conditions, the deformation of soil with fine particle size is larger than that of soil with coarse particle size.

Key words: thick unconsolidated layer, confined aquifer, dewater settlement, ground movement and deformation, simulation test