Minicage ® Cable Bolt

Physical Properties (Single Strand Only)

 

Minicage ®MinimumTypical
Yield Load at 0.2% Elongation212kN250kN
Ultimate Tensile Strength250kN265kN
Elongation on 600mm Gauge Length3.5%6.5%
Uniform Elongation4%%
Mass per Metre1.13kg
Nominal Strand Diameter
15.2mm
Cross Sectional Steel Area in Cable143mm2

 

 

 

 

General Features

  • Manufactured from stress relieved, low relaxation, high strength 15.2mm diameter 7 wire steel strand, the Minicage ® cage cable bolt is formed by bulbing the strand into small cages, typically 26 to 28mm diameter, and up to 6 Minicages ® per metre.
  • The Minicage ® cable bolt cages can be modified, in cage frequency and diameter, so that geotechnical engineers are able to design specific reinforcement products to suit ground conditions. In some cases de-bonding tube can be added to the lower section of the bolt to allow for pre-tensioning.
  • The Minicage ® Cable Bolt is supplied in either single, double or in combination forms. Single Minicage ® plus single plain cable. They are supplied in nominated lengths for grouting into holes from 35mm to 105mm diameter.
  • Can be used with cementitious grouts as well as polyester resin when early support is required.
  • For up hole applications, cable bolts are fitted with a spring wire "fish hook" to hold the cable bolt up the hole.
    Surface confinement is provided by flat or domed plates and barrel and wedge anchors. Please refer to appropriate pages for slotted or multiple hole plates, barrel and wedge anchors, grout and air bleed tubes

Installation

Guidelines (In vertical or up holes with cementitious grout)

  • In coal mining applications, the preferred hole diameters are 35/36mm for single Minicage ® Cable Bolts and 50mm for double Minicage ® Cable Bolts.
  • Holes are drilled approximately 200mm shorter than the bolt length. If the bolts are to be tensioned, a tail of between 200 to 500mm is required, dependent on the type of tensioning unit to be used.
  • The Minicage ® Cable Bolt is prepared by attaching a breather tube to the full length of the bolt. Allow an excess of breather tube, say 2 metres, to protrude from the hole mouth.
  • Similarly attach approximately 1 metre grout tube to the bottom of the cable with sufficient tail to connect to the pump.
  • The Minicage ® Cable Bolt is inserted into the hole & the hole mouth is sealed to eliminate loss of grout when pumping.
  • Connect the grout tube to the pump. The air bleed (breather) tube is placed into a container of water and pumping commenced. Air bubbles will exhaust from the breather tube while pumping and be visible in the water container. When the hole is full of grout, these air bubbles will cease to flow.
  • After the grout has cured, the bolt can be tensioned if a de-bonding tube has been fitted.

Standard Lengths & Packaging

  • Standard bolt lengths range from 3000 to 30000mm in 300mm increments.
  • Non-standard requirements are available by negotiation.
  • Minicage ® Cable Bolts are normally supplied in straight lengths up to 6 metres and bundled. Cables over this length are usually coiled.

Notes

  • Only DSI rock bolt components should be used in order to obtain full performance of the bolt system.
  • DSI's Mining Products Division is Quality Assured to ISO 9001:2000, Registration No.QAC/R61/0315.