The repeated mining face layout,equipment selection and extraction technology with cataclastic roof had been designed.

The anchoring theory, technology and its application effect on thin-bedded and cataclastic roof are important topics to be studied The geomechanics condition, surrounding rock characteristics and construction method of the starting cut with large section in a fully mechanized mining are introduced.

It analyses the reasons which causes the common quality problems including pile cracks,pile-top breakage,substandard sinking-pile design requirements and splitting joint,and brings forward the protecting measures and solving plan,so as to ensure the constructing quality and the safety of top structure.

Prevention and control technology for spalling and failing of high inclined broken roof in fully mechanized mining face;

Research on broken roof consolidation technology in coal ming face;

Mechanism and project practices on broken roof control with wood bolt in fully mechanized coal mining face;

Cause analysis on roof broken in mine gateway retained for next sublevel in Xinghua Mine as well as prevention and control;

Application of supporting technology combination of anchor cable and bolt in friable roof support;

Drecting to the difficult controlling problem of friable roof in blasting coal face near the gob area and based on the conventional longwall mining method, Sihuaishu Coal Mine succeeded in the extraction of No.