Aimed at the technical difficulties of gob-side entry retaining in fully-mechanized coalface with top-coal caving (GERFCTC), a new technique of entry-in packing is put forward. In this technique, there are three key aspects: (1) to set up the reasonable mechanic model of surrounding-rock structure; (2) to maintain the integrity of the top coal for the entry with large-section in the coal seam; (3) to control the stability of the packing body with large bulk and long distance. In order to use the new technique in the entry, which has been excavated with normal section for several years, supported by ladder-shaped steel rigid support, actual steps are put forward. The results of industrial test and field measurement show that the technique is used successfully. It can be applied in similar conditions of fully-mechanized coalface with top-coal caving (FCTC).

The geological conditions of coal seam are evaluated quantitatively by using fuzzy method and from pointview of coal mining. According to the evaluation results, decision-making on mining techniques, mining programming and design, production management can be carried out effectively. The latest developments in China are introduced. The evaluation contents, the structure and index system of evaluation factors, the membership functions and weights of evaluation factor, evaluation model and reliability are stated in detail. The effective application of fuzzy evaluation in the prediction of coal face output is introduced emphatically. Fuzzy evaluation on geological conditions of coal seam is the basic work that ensures a mine run efficiently, safely and steadily.

According to the technical requirements of gob-side entry retaining in fully mechanized coalface with top-coal caving, the bolt and cable, instead of the original I-steel trapezium-shaped support, are used to reinforce the belt entry, which is excavated in thick coal seam. The reinforcing scheme and parameter of bolting with wire mesh and cable are introduced emphatically. The technique has been used in Chanchun Coal Mine of Luan Coal Group, and the good reinforced effects are also shown by the field measurement results. The reinforcing technique lays a good foundation for the successful test of gob-side entry retaining in fully mechanized coalface with top-coal caving.