Abstract:Risk assessment of water inrush from coal floor is a complex problem of theory and technology,which is concerned with hydrogeology,engineering geology,mining conditions and rock mechanics. To aim at the above-mentioned problem,the expert system for risk assessment of water inrush from coal floor is combined with experts¢ experiences and theoretical achievements with artificial intelligence technology,adopting two inferred methods,which are the water inrush coefficient and the preferred water inrush plane. The inference strategy of weighted analogy analysis of typical water inrush cases is put forward. This system is basically capable of forecasting the development of limestone karst and potential fault structure below the coal floor. This system is composed of four knowledge bases,i.e. base of typical water inrush cases,base of expert experiences,base of theoretical achievements,and base of water control measures. The risk,location and type of water inrush can be forecast and assessed through this system. Simultaneously,this system also has a great consultant value for water inrush from coal floor. The answer of simulation analysis applying this system to the realistic water inrush cases is in good accordance with the truth condition. The expert system will be of some values for controlling and preventing water inrush from coal floor.