Rock Bolts

Rock bolts are short, low capacity reinforcements, which enhances the strength of unstable rock masses and limit shear displacements. Rock bolting is as an economic, safe and effective form of rock support. The reinforcing element (steel or GRP bar) is drilled and grouted in the ground. It can be either an active system with predetermined level of stress or a passive system without any prestress. Main types of rock bolting are mechanically anchored rock bolts and grouted rock bolts.
Rock bolts are used in tunneling works to support portal face and tunnel roof, as well as for fore-poling. Other applications are to stabilize slopes and fix rock fall barriers.
The reinforcing element of rock bolting can be in solid threaded bar, self-drilling hollow bar or GRP bar.
rock-bolt

Rock Bolts with Threaded Bar

Threaded solid bar with hot rolled, coarse pitch, continuous thread is a suitable reinforcement for rock bolting.

Benefits of Threaded Bar System

  • Steel bars can be cut and coupled with out any additional threading at site to connect couplers
  • Splicing of bars using coupler is easy
  • Threads being hot rolled and with coarse pitch make it screw-able in challenging site conditions, thus making it suitable for geotechnical applications.
  • High relative rib area provides maximum bond stress between steel bar and cement grout

Threaded Solid Bars are available in

  • 500/550: Ø16 - 75 mm
  • 550/620: Ø20 - 75 mm
  • 670/800: Ø18 - 75 mm
  • 950/1050: Ø18 - 75 mm
Rock bolts are also available in types shown below.
rock-bolt
For more details on Threaded BarClick Here
rock-bolt

Rock Bolts with Self-Drilling Hollow Bar

Self-drilling hollow bar is a suitable reinforcement for rock bolting. Hollow bar offers fast, easy and flexible system in any soil conditions, which simultaneously acts as the drilling rod (with lost drill bit), grouting tube and reinforcement bar (tendon). In unstable soils, additional operations of inserting and extracting the casings are avoided.

Self-Drilling Hollow Bars are available in

  • R25 to R51, R-type threads
  • T30 to T135, T-type threads
For more details on Self-Drilling Hollow BarClick Here

Rock Bolts with Glass Fibre Reinforced Plastic (GRP)

GRP bolts offers a viable alternative to steel reinforcement. Being light weight, GRP bolts are easy to install in challenging conditions. GRP bolts doesn’t need to be removed from ground, as it can be cut by earth moving equipment or tunnel boring machines during future construction.
For more details on GRPClick Here