Abstract：The automatic monitoring and predicting system are significant for actively treating quicksand hazards in mining engineering. The centrifugal model tests emphasize the variations of pore water pressure and the concentration and dissipation of the excess pore water pressure in clay layers above the mined-out area and coal pillars，and the maximum excess pore water pressure can be increased by 15%–20% of the vertical dead-weight stress at the monitoring point. A mining-induced pore water pressure simulation experiment shows that the variation of the pore water pressure in a confined aquifer due to mining is closely related to the mining progress and periodic roof pressure. The pore water pressure in the aquifer above the coal pillars generally increases firstly and decreases then during mining. The pore water pressure variation in the aquifer above mined-out area is related to the location of working face，which decreases obviously when working face just passes the said point，and increases for a period of time while the monitoring point lies above the mined-out area. Quicksand model tests show that，when water inrush and quicksand start，instant negative pore water pressure is recorded at first，then the water head stabilizes at a low level for a period of time as the other sensors around the fissure demonstrate a water funnel with certain hydraulic gradient. It can be deduced from these results that the pore water pressures can be of important precursor significance for monitoring and forecasting the quicksand hazards in mines.
