Articles
Sinorock R51 Self-drilling Rock Bolt in Tunnel Roof Support
by Anchor S. Web DesignerThe Zhengwan high-speed railway is 818
kilometers long, connecting Zhengzhou, Henan and Wanzhou, Chongqing. It is an
important part of the Beijing-Kunming corridor in my country's eight-horizontal
and eight-vertical high-speed railway network, and it is also a newly planned
railway included in the national "Twelfth Five-Year Plan" period.
Construction started at the end of 2014 and is expected to open to traffic in
2022.
The Gaojiaping Tunnel of the ZWZQ-5 bid
section of the Hubei section of the Zhengwan High-speed Railway has complex
engineering geology, difficult construction and high safety risks. The inlet
section is V-grade surrounding rock, mainly composed of medium-strong weathered
shale, weak surrounding rock and high water-rich karst cave, broken rock mass
and poor self-stability, and the lining type is Vcw composite lining. During
the construction process of China Railway 11th Bureau, Sinorock R51
self-drilling bolts were used as advanced pipe shed support, instead of
traditional steel pipe sheds.
There are 50 holes per ring at the top of
the end face. The hole spacing is 400mm, and the hole depth is 25 meters. The
hole is inclined upward at an angle of 7°. When drilling, we use R51/76
tungsten carbide button drill bit, and the hole diameter is 76mm. After the
drilling is completed, the grouting shall be carried out. The water-cement
ratio of the cement slurry is 1:1, and the grouting pressure is 0.5-2.0MPa.
After the grouting is completed, the orifice shall be blocked with a grouting
plug.
It has been verified by the practice of the
Gaojiaping Tunnel that the self-drilling hollow bolt is safer and more
efficient than the traditional pipe shed for drilling and installation under
this geological condition.
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About Anchor S. 
Web Designer
8 connections, 0 recommendations, 87 honor points.Joined APSense since, July 30th, 2020, From Beijing, China.
Created on Apr 25th 2022 04:54. Viewed 207 times.
