A.40 B.45 C.35 D.30
A.75% B.80% C.70% D.85%
A.采用超前注漿加固 B.根據(jù)土質(zhì)確定合適的開挖進(jìn)尺 C.利用圍巖的自承能力 D.及時支護(hù)