A.靜水壓力B.動(dòng)水沖擊力C.靜水力矩D.動(dòng)水力矩
A.百分之三十B.百分之四十C.百分之五十D.百分之六十
A.自洞口計(jì)起,當(dāng)洞挖長(zhǎng)度不超過(guò)15m~20m時(shí),應(yīng)依據(jù)地質(zhì)條件,斷面尺寸,及時(shí)作好洞口的臨時(shí)性或永久性支護(hù)B.支護(hù)長(zhǎng)度一般不小于5mC.在洞室群和洞室交叉地段,宜采取先小洞后大洞的原則組織施工D.特大斷面洞室,宜分層開(kāi)挖并對(duì)上層開(kāi)挖部位支護(hù)結(jié)束后方能進(jìn)行下層開(kāi)挖