Coal 2015

Strength Characteristics of Secura™ Hollow Groutable Cable Bolt ( HGC)

Naj Aziz - UOW Robert Hawker - Orica Australia

and Ali Mirza, Jan Nemcik, Xuwei Li, Haleh Rasekh

February 11-13

Coal 2015

Outline

• Introduction

• Secura™ HGC Bolt

• Tensile Strength Test

• Single Shear Test

• Double Shear Test

• Conclusions

February 11-13

Coal 2015 February 11-13

Secura™ Hollow Groutable Cable bolt (HGC)

Diameter: 30 mmStrands: 9 Cable Tensile Strength: 680 kN

Strand Cross section Area

(mm2)

Coal 2015 February 11-13

a

b

Tensile Strength (BS7861-2, DEPT)

(a) Tensile pull test set up and (b) snapped section of the cable bolt

(b) Average Peak loads of 680kN from tests slightly exceed theoretical load from individual strand testing of 644kN)

Coal 2015 February 11-13

b

Tensile Strength Strand Failure

All strands exhibited necking, cone and cup failures identifying uniform cable tensile loading

Coal 2015 February 11-13

Single Shear Test (BS7861-2)

Coal 2015 February 11-13

Load-displacement graphs of single shear tests

Single Shear Test of Secura™ HGC

Coal 2015 February 11-13

Single Shear Test of Secura™ HGC

Coal 2015 February 11-13

Double Shear Testing

Coal 2015 February 11-13

Coal 2015 February 11-13

Test No 1: Shear load per face : 800 kN . Axial Load : 270 kN. Grout : FB400Test No 2: Shear load per face : 772 kN . Axial Load : 97 kN. Grout: Carbothix

DOUBLE SHEAR TESTSCONCRETE: 40 MPa

Coal 2015 February 11-13

* Assumed 430 kN single shear result for ration reduction

If 10 % allowed for concrete shearing force, then DS Test/ SS test will be 1.7 and 1.62

Coal 2015 February 11-13

Conclusions• Tensile failure loads slightly exceed theoretical combined strand loads

indicating even load distribution for cable

• Single shear loads are 63% of Tensile Load

• Single shear testing of the cable bolt (based on BS7861 test procedure) yielded 40% lower load when compared to Double shear test

• The peak shear failure loads achieved using cement grout (FB400) and pumpable resin (Carbothix™) within same range

• Axial loads during shear testing within same range when using cement grout (FB400) and pumpable resin (Carbothix™)

• No cable rotation was detected in Tensile (DEPT) or double shear testing in either cable bolt

Coal 2015

TURKISH SOMO MINE DISASTAR -2014

ITU –Mining Department and the names of fatalities

February 11-13

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