天(tian)井(jing)(jing)(jing)施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)是在地(di)下(xia)巷(xiang)道之間的豎直或傾斜聯絡通道、煤倉、暗井(jing)(jing)(jing)等工(gong)(gong)(gong)(gong)程，由于(yu)無法(fa)像地(di)面施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)井(jing)(jing)(jing)筒那樣，布置穩車、絞車等大(da)量(liang)設備(bei)，一般要采(cai)用反(fan)(fan)井(jing)(jing)(jing)法(fa)。施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)反(fan)(fan)井(jing)(jing)(jing)是先由下(xia)向上(shang)掘出小斷(duan)面溜渣孔，然后再由上(shang)向下(xia)刷大(da)成井(jing)(jing)(jing)。反(fan)(fan)井(jing)(jing)(jing)和刷井(jing)(jing)(jing)過(guo)程中(zhong)破碎下(xia)來(lai)的巖石(shi)和地(di)層涌(yong)水(shui)，通過(guo)溜渣孔落(luo)到下(xia)水(shui)平。傳(chuan)統的反(fan)(fan)井(jing)(jing)(jing)施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)方(fang)法(fa)，需要人(ren)員進入工(gong)(gong)(gong)(gong)作面工(gong)(gong)(gong)(gong)作，而(er)采(cai)用反(fan)(fan)井(jing)(jing)(jing)鉆機鑿井(jing)(jing)(jing)，則實現反(fan)(fan)井(jing)(jing)(jing)施(shi)(shi)(shi)工(gong)(gong)(gong)(gong)機械化。

天井(jing)鉆(zhan)機的額定功(gong)率一般為125～450kW，動(dong)力輸出扭矩為120～400kN·m，成孔直徑(jing)可達1.5～4m，成孔尺度為60～90m，可以滿足(zu)各類(lei)大型基礎施工(gong)的要(yao)求(qiu)。