TECCO® mesh for ground support in underground mining

TECCO ® mesh for ground support 

in underground mining 

Fast, safe and fully mechanised installation with 

the ROCK MESHA ® installation handler 

TECCO ® Underground / Technical documentation / December 2009

TECCO ® Underground / Technical documentation / December 2009 

TECCO ® mesh for ground support 

in underground mining 

Fig. 1: Geometry of the TECCO ® mesh 

and the delivery of the mesh in rolls 

2 

1. TECCO ® FOR SURFACE SUPPORT IN TUNNELS 

TECCO ® mesh offers a support system for most ground conditions. It is made 

from high-tensile steel wire with a tensile strength of 1’770 N/mm 2 . The wire 

is sufficiently tough and does not behave in a brittle manner. It can be 

stretched over sharp rock edges without sustaining damage. The mesh is 

diamond shaped and along the edges, the wires are bent over and double 

twisted in such a way that this connection is as strong as the mesh itself. The 

mesh is produced in rolls and can be manufactured in widths of up to 3.5 m 

and in tailor-made lengths corresponding to the tunnel surface. 

Due to the use of high-tensile wire, the mesh is very light in relation with its 

strength (2.6 kg/m2 ). For corrosion protection, the wires are coated with a 

special aluminium-zinc coating (GEOBRUGG ULTRACOATING ® or GEOBRUGG 

SUPERCOATING ® ) which has a higher corrosion resistance than standard galvanising. 

Comparison tests with conventional galvanized wires yield at least 

a three to four times longer lifespan. 

A special equipment, the ROCK MESHA installation handler, offers a fast and 

safe application of the mesh. 

1.1 Field of applications: 

• General surface support in tunnels (mesh only or mesh in shotcrete) 

• Failures in high stressed ground conditions (rockburst) 

• Squeezing ground 

• Subsequent reinforcement of shotcrete solutions 

• Tunnel reconstruction 

1.2 TECCO ® mesh 

For poor or seismic ground condition, this high-tensile steel wire mesh has 

proven its performance and suitability for the application as rock burst support 

or support for high-deformable ground during static and dynamic tests 

at the Western Australian School of Mines (WASM). Due to the high-tensile 

wire strength and ability for high deformation of the high tensile mesh, this 

ground support system can be used in high stress environments.

2. TESTING OF THE HIGH-TENSILE CHAIN-LINK 

MESH TECCO ® 

In order to determine the mechanical properties of the mesh, TECCO ® was 

tested extensively for static and dynamic loading at the Western Australian 

School of Mines (WASM). 

2.1 Static testing 

The static response of high-tensile chain-link mesh was determined by test 

work in the WASM laboratories in Kalgoorlie. The figure opposite shows the 

response of three samples of the high-tensile mesh TECCO ® G80/4 where a 

1.3 x 1.3 m panel was loaded with a 300 x 300 mm steel plate. The hightensile 

mesh was able to bear a load of up to 100 – 110 kN before it failed 

at the edge of the loading plate. Weld mesh in comparison failed with approximately 

40 kN, and mild steel chain-link failed with less than 20 kN using 

the same test setup. All mesh types require some displacement at the beginning 

to be activated and loaded. 

It was also found that the high-tensile chain-link mesh can sustain an in 

crease in load even after a wire has failed. It also does not unravel once a 

wire has failed. In earlier tests, the high-tensile mesh was tested in a way 

quite similar to an application in tunneling (with four bolts and plates). It 

was established on that occasion that the rupture is generally starting at 

the crossing points but is not sheared over the edge of the plates due to the 

higher steel quality of the mesh compared to the mild steel plates. 

2.2 Dynamic testing 

By using the momentum transfer method the TECCO ® mesh was tested at the 

dynamic testing facility of WASM. The mesh panel is installed in a loading 

frame in which a steel weight can be dropped onto the mesh from different 

heights. The rebound of the loading frame is stopped by buffers while the 

loading mass impacts the mesh sample without being separated. This test 

arrangement simulates the situation with installed mesh in tunnels. The 

whole dynamic tests are instrumented with high-speed video cameras, load 

cells and accelerometers. 

Fig. 2: Test arrangement und force 

displacement responses of three 

samples of the high-tensile chain-link 

mesh TECCO ® G80/4 

Fig. 3: Photo from underneath the test 

arrangement before the first loading as 

well as from the high-speed video 

camera 

3


Fig. 4: Dynamic impact of a 1000 kg 

mass into the high-tensile chain-link 

mesh 

4

It was established that the high-tensile chain-link mesh is able to absorb 

energies of up to 10 – 12 kJ in such a configuration. This is equal to stopping 

a rockburst mass of 1000 kg which was previously accelerated to 4.5 – 5 m/s. 

This value represents the value of the energy absorption of the mesh only 

and does not include any absorption by the rock mass itself or the yielding 

bolts. Welded wire mesh (wire diameter 5.6 mm and 100 mm wire spacing) 

showed energy absorption capacities in the area of 1 – 2 kJ in the same test 

setup. 

2.3 Numerical model 

Using the calibrated finite element program it is possible to simulate and 

vary the dynamic response of any project boundary condition for setup and 

loading. 

Fig. 5: Calibration of the numerical 

model as a result of static testing 

5


Fig. 6: 3,50 m wide handler mounted on 

a twin boom Jumbo 

6 

3. INSTALLATION OF TECCO ® MESH IN TUNNELS 

The difference between the installation of welded wire mesh and the instal- 

lation of TECCO ® mesh is the stiffness of the products. The welded wire mesh 

is relatively stiff and is delivered and applied in sheets. The TECCO ® mesh is 

only stiff in one direction but rollable in the other. Therefore it is delivered 

in rolls and will be installed in a different way to welded wire mesh. 

3.1 Fully mechanised installation with the ROCK MESHA installation 

handler 

A mechanical handler for the application of TECCO ® mesh, the ROCK MESHA 

installation handler, was developed by ROCK Australia Pty Ltd and success- 

fully tested in Australia and Switzerland for the use in underground mining 

ground support. This handler applies rolled high-tensile chain link mesh and 

is compatible with all standard multi-boom underground drill rigs. The hydraulic 

circuit normally used for the feed arrangement can be used to operate 

the handler components. 

The handler is manipulated from the cabin of the drill to pick up a roll of 

TECCO ® mesh, minimising physical manual handling, the mesh is then able 

to be positioned on the walls and backs for bolting, using the drilling component 

of the opposite boom. 

3.2 Main benefits of TECCO ® mesh in combination with ROCK MESHA 

installation handler 

• Faster and safer installation 

• Cost saving due to the faster installation times, utilisation and 

material savings 

• Improved quality 

• Can be retro fitted to any multiboom Underground Jumbo, 

Cable bolting or Roof bolting drill rig

Fig. 7-9: Installation of the TECCO ® 

mesh with a two-boom jumbo 

7


Antam Mine / Indonesia 

Mesh: TECCO ® G80/4 mm 

Nails: Split sets 

Secured area: 300 m 2 

Object: Mine 

Installation: 2009 

They nailed half of the width of the 

mesh only before they did the next 

cutback. Therefore part of the blast 

is supposed to go into the mesh. No 

damage occurred during next day‘s 

blast. 

Valvidriera‘s Tunnel, Barcelona / 

Spain 


Object: Road tunnel 

Underground: Limestone 


8 

4. REFERENCES

PCH São João, Castelo / Brasil 


Tunnel Raul Veiga, Niteroi / Brasil 


Nails: Gewi ø 28 mm 

Nail length: 7 m 


Object: Road tunnel 

Underground: Gneiss 


TECCO ® G65/4 mm 

Nails: Gewi ø 25 mm 

Nail length: 2 m 


Object: Underground 

cavern of a power- 

house 

Underground: Granite 


9


Leinster Mine / Australia 




Object: Mine 


Leinster BHP Billiton Nickel West 

Mine / Australia 



Secured area: 360 m2 Object: Mine 


10

5. CONCLUSION 

The main advantages of the TECCO ® mesh for ground support in under- 

ground mining are as follows: 

• Simpler, safer and faster mechanized installation 

(40% - 50% faster) 

• Higher energy absorption on dynamic impact 

• Rolls of mesh are mechanically picked up by the jumbo with the ROCK 

MESHA installation handler, eliminating manual handling in unsupported 

ground 

• Different width of the mesh with wire diameter of 4 mm, 3 mm or 2 mm 

are available 

• Less over-lapping of mesh in tunnels and drives 

• Better corrosion protection 

• For strengthening of tunnel walls the mesh may also be unrolled / bolted 

in the longitudinal direction 

Possible horizontal application 

11

Geobrugg protects people and infrastructures from the 

forces of nature 

It is the task of our engineers and partners to analyze the problem 

together with you in detail and then, together with local consultants, 

to present solutions. Painstaking planning is not the only thing you 

can expect from us, however; since we have our own production 

plants on three continents, we can offer not only short delivery paths 

and times, but also optimal local customer service. With a view to- 

wards a trouble-free execution, we deliver preassembled and clearly 

identified system components right to the construction site. There 

we provide support, if desired, including technical support – from 

installation right on up until acceptance of the structure. 

A company of the BRUGG Group 

Rockfall barriers 

Rockfall drapes 

Slope stabilization systems 

Rock protection 

Debris flow barriers 

Avalanche prevention structures 

Open pit rockfall barriers 

Geobrugg AG 

Protection Systems 

Aachstrasse 11 • CH-8590 Romanshorn • Switzerland 

Phone +41 71 466 81 55 • Fax +41 71 466 81 50 

www.geobrugg.com • info@geobrugg.com 

ISO 9001 certified 

1.402.15.EN.1004

TECCO® mesh for ground support in underground mining

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?