Key Technologies for Borehole Drilling by Rotary Drilling Machines in Heterogeneous Ground: Case Study on Bored Piles of Vertical Shaft of Xiangjiang River Crossing Tunnel

ZHAO Quanmin

Tunnel Construction . 2013, (6): 510 -514 . DOI: 10.3793/j.issn.1672-741X.2013.06.013