第一辅助洞没有斜井或竖井，施工辅助洞采用全射流纵向通风。第二辅助洞埋深大，洞体长，洞形断面小。

First, there is no slope hole or silo, the auxiliary hole of construction adopts longitudinal ventilation only by jet Second, it belongs to deep buried hole, long body, little shape section.

youdao

第一辅助洞没有斜井或竖井，施工辅助洞采用全射流纵向通风。第二辅助洞埋深大，洞体长，洞形断面小。

First, there is no slope hole or silo, the auxiliary hole of construction adopts longitudinal ventilation only by jet Second, it belongs to deep buried hole, long body, little shape section.

youdao