During the anchoring and shotcreting construction at the rock headingblast advancement face, problems such as support strength can not be guaranteed or engineering quality uneasy to control exist.
岩巷炮掘工作面的锚喷施工存在支护强度得不到保证、工程质量不易控制等问题。
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Out of this world: NASA staff watch Apollo 11 blast off from the Kennedy Space Center, Florida, on July 16, 1969, heading to the Moon carrying Neil Armstrong, Buzz Aldrin and Michael Collins.