1·The blasting vibration rules of arch crown and upper and side surrounding rocks behind tunnel face are studied.
研究隧道掌子面后方隧道拱顶、掌子面正上方和侧面围岩的爆破振动规律。
2·In addition, comparison of arch crown settlement and horizontal convergence of haunch between in-situ testing data and computing ones shows that the variation laws fit preferably.
另外，现场实际量测拱顶下沉数据和拱腰水平收敛值与计算数据的相互比较表明，两者变化规律吻合较好。
3·The keystone in the crown of an arch.
给…盖拱顶给…建造或盖以拱顶；
4·The placement of the incisor teeth bracket was in the middle of the clinical crown, and retention arch wire was straight wire without step bends.
其最大特点是既反映大多数牙的临床牙冠中点，又对某些牙位托槽位置进行了调整，实现了无弓丝弯曲的直丝弓矫治目的。