The paper emphatically analyses the interaction between the wall stress characteristic and coal getting by impact on the longwall face, proposes the work pattern of coal breaking by impact.
看重分析了长壁采煤工作面煤壁应力特点和冲击劈裂式采煤的相互作用关系，提出了冲击破煤的作业方式。
2
The characteristic is provided with inheritance unlti_periods and difference, and its main form is interrupted sinking and a series of movement breaking tape is formed.
其特点是具有继承性、多期性和差异性，主要表现形式为间歇性下沉，并形成了一系列活动断裂带。
3
The influence of breaking current on arc characteristic is also measured.