Research of observed test on safety exploiting depth of mining under buildings

In this paper,Starting from the concept of safety exploiting depth, through analysing surface displacements observation station test, this article has confirmed the safety exploiting depth exist while mining under buildings, and has also shown that the safety mining depth even exist in different mining geological, but the values of safety mining depth are different. These conclusions have also supplied technical evidence for solving the problem of safe working of three unders in coal mining especially mining under buildings.