rock bolt of Sinorock was applied widely in the tunnel construction


Posted May 16, 2016 by sinorockbolt

rock bolt of Sinorock was applied widely in the tunnel construction

 
Tunneling technology experienced a sea of change when engineers in the 1970s developed TBMs that could automatically install a precast
concrete lining as they made their way through rock or even under water. Electronic sensors and monitors also allow modern TBMs to avoid
existing structures as they’re digging. The machines can also emit chemicals that can loosen or harden soil as necessary during tunneling
operations. All of these innovations have made it possible for tunneling to be put to use in areas that were previously considered unsafe
or impassable, such as a recent traffic tunnel in Miami, which had to be carved out of wet sand and coral, according to The Journal.

Tutor-Perini and Seattle Tunnel Partners haven’t had much luck with their tunneling operations underneath Seattle since the TBM, dubbed
Bertha, broke down in December 2013, which put Bertha out of commission for two years. After a few days of resumed digging in January of
this year, tunneling operations were stopped again because of a sinkhole that formed near Bertha’s boring path. As a result, Washington
Gov. Jay Inslee ordered a halt to all boring operations and only released the order when Tutor Perini, which called the stop-work order
"wrongful and unjustified," came up with a plan to improve monitoring of tunneling operations.

Another "tunnel-challenged" endeavor is the California High Speed Rail Authority’s bullet train project, which will, eventually, have to
bore 36 miles through the San Gabriel and Tehachapi Mountain ranges, as well as through earthquake faults and other untested areas. So
daunting and expensive was the prospect that the authority sidelined that segment of the rail system for the time being and has decided to
start on a more topographically friendly route in Northern California.

The rock bolt was applied widely in the tunnel construction. However, the traditional equilong rock bolt can not connect the surrounding rock effectively in the nearly zone and the shear stress on is so large to lead to the length limitation. While the combination of the long rock bolt and the short rock bolt can foster strengths and circumvent weaknesses. The supporting effect is definitely better.


In the combining support of the long self drilling rock bolt and short self drilling rock bolt, the former on one hand controls the deformation of surrounding rock except the reinforced composite arch. On the other hand, it can reinforce the combination arch structure to hang on the stable rock for coordinate deformation of surrounding rock.

Relating to the short rock bolt, it can reduce the hulking deformation of the rock and the further damage of the fracture by limiting the deformation of the near area and the development of the fracture surface. The short rock bolt can also form reinforced composite arch structure which has a certain bearing capacity near tunnel surrounding rock. All these can strengthen the integrity and stability of the surrounding rock effectively.
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Last Updated May 16, 2016