The right upper pre advancement section was constructed from February 5 of 1997 to February 19 of 1997 and the 150 W hydraulic motored vibroflot was adopted.
右上段进占施工时间1997年2月5日~2月19日,采用液压驱动150kW振冲器。
The left lower pre advancement section was constructed from April 21 of 1997 to April 28 of 1997 and the 75 W vibroflot was adopted.