The in-situ practices show that most rock bursts occur in the frontabutment scope ahead of the coal face.
现场实践表明，大多数冲击地压发生在工作面煤壁前方超前支承压力范围内。
2
The washing water height in front of the abutment has the opposite tendency, with the high washing water height in the downstream and the low washing water height in the upstream.