承压水底板关键层
floor water-resisting key stratum
底板关键层
key stratum of pressed floor
隔水关键层
water-resisting key strata
water-resistant key strata
关键层复合破断
key strata compound breakage
关键层理论
theory of key stratum
the key stratum theory in ground control
key stratum theory in ground control
组合关键层
combinatorial key stratum
combinatorial key strata