We are puzzled by the pervious to water,the underground coal seam fire prevention,the question of deep zone mining and coal mining from incidence in Jixi.

Longwall actual mining technology for large inclined angle face;

Analysis and ascertainment of people's operation reliability at coal face;

The support power of the trend longwall coal face;

The gas density is higher at coal faces in the key-point area of gas management.

Application of a new pattern of hydraulic propeller in mining face;

It is widely used in the push of transporter of each type in mining face of coal mine underground.

This paper analyzes the regularity of the gas emission in mining face and its main influencing factors,and expounds the gas treatment and control technology.

Through analyzing Principal Component Analysis(PCA) and Gene Expression Programming(GEP),a novel GEP Algorithm based on PCA is proposed and applied to predict the amount of gas emitted from coalface.

The prediction of the amount of gas emitted from coalfaces is the basis of ventilation system design and safety measurement implementation.

Based on some typical examples of gas explosions on the coalface,the basic events resulting in gas explosions are generalized and a fault tree is drawn.