The confined water inrush is typically caused by fault activation under high ground pressure due to coal mining. It is one of the main forms of water disaster in deep mining in North China. Based on the equipment of similar simulation tests

we designed the testing device and proposed the testing method. Fault F13 in Wugou mine was chosen as a geological background in this study. Then the overburden movement

the expansion characteristics of the bottom plate

the stress and structure evolutions of the fault zone and the whole process of the aquifer were investigated. Taken the mining distance as a time reference

the water inrush consists of four obvious stages: the yield of fault zone caused by over-stress

cracking and extending of the fault zone

diastrophism and slip of fault zone

rising of confined water. Based on the height of the pressurised water along the fault zone

its correlation factors were analysed. It was found that the relationship between the mining distance and confined water rise was an approximately negative liner. Moreover

the pressure of confined water showed positive correlations with the width of the fault zone and the height of confined water. In particular

the correlation between the pressure of confined water and the height of confined water exhibited a strong-weak-strong law during the whole experiments. According to the obtained experimental result

the waterproof coal pillar was designed as 40 m in the fault F13

and the no water leakage and inrush were found. This indicates that the designed height is reasonable. Therefore

this study can provide a useful reference to understand and prevent mining water disasters.