基于烟圈效应的11点超前探观测系统设计

Eleven point observing system in advanced detection based on smoke ring effect

矿井瞬变电磁法因关断时间影响存在一定探测盲区,一定条件下关断时间长短取决于发射回线边长、等效面积。针对掘进巷道迎头有限空间,设计采用多匝、重叠小边长回线以满足探测深度需要。研究计算表明,40匝、2 m×2 m的发射回线盲区范围为20 m左右,并据此首次提出了矿井瞬变电磁法测点间距选择盲区理论法。基于"烟圈效应"设计了适用于不同巷道条件下的"11点法"矿井瞬变电磁超前探观测系统。该系统随煤/岩层倾角变化而变化。通过推理计算得到了与煤/岩层倾角相关的线框布设角度公式,使该系统更具实际应用价值和指导意义。

The multi-turn,small side coincident loop is used to meet the needs of probing depth and adjust the lim-ited roadway space.There are blind zones as a result of turn-off time in TEM.The turn-off time depends on the side and equivalent areas of transmitter loop under certain conditions.The calculations show that the blind area is about 20m on the condition of 40 turns and 2m×2m transmitter loop.And then the distances selection method be-tween the near two detection points based on blind zone theory is proposed.＂11 points＂ advanced detection ob-serving system is designed to adjust different conditions based on smoke ring effect,which varies with the coal/rock inclination.The loop layout angles are calculated to fit different coal/rock inclination,which makes the system have more important practical value and significance.