键槽,键座
study on the key bed theory of roof supporting in stope
采场支撑顶板关键层理论的研究
at the section with non lithology key bed, the key bed could be selected according to the lithology combination and the particle variation.
在无岩性标志层的层段,则根据岩性组合及粒度变化选择标志层。
as for the key bed, the muddy limestone and the aluminum mudstone with stable thickness were selected as the key beds.
在标志层方面,选择厚度较稳定的泥质灰岩、铝质泥岩作为标志层;
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