TECCO^® SYSTEM³

Greater protection with high tensile strength steel wire mesh:

• High-tensile strength
• Field-tested concept
• Efficient protection
• GEOBRUGG SUPERCOATING®: long lifespan
• Quick and easy to install

Catchment area too small - kinetic energies too high ... now what?

Dynamic rockfall barriers - certified energy absorption up to 5000 kJ - have proven their worth as reliable protection from rockfall events and as the most economical solutions. However, in situations where the

• Catchment area is too small
• Expected rockfall bounce heights are too high
• Expected kinetic energies are too high

The use of rockfall barriers is impossible. In such cases, nailing the slope as a stabilizing measure in combination with high-tensile TECCO® steel wire mesh can be very effective, however over large areas cost intensive. Instea,d rock coverings are often used, with variable results:

• Wire rope nets with underlaid wire netting are associated with higher installation costs.
• Diagonal wire netting and hexagonal wire netting are often too weak. According to an independent study, these conventional nettings are best suited for rock sizes up to 0.6 x 0.6 x 0.6 m.

We have addressed the needs of planners and safety professionals for protection that is more effective and still economical in areas where rockfall protection barriers cannot be constructed to protect highways, railroad tracks and settled areas. The new TECCO® rockfall drape made of high-tensile steel wire is the result. True to our company policy of offering only field-tested products, we have tested the components and overall concept intensively. Independent testing institutions have verified the results. Narrow meshes in the shape of rhomboids make underlay netting needlessly redundant. You save on installation costs because coverage per mesh panel is extensive. We supply the TECCO® rockfall drape with GEOBRUGG SUPERCOATING® corrosion protection. This means you can count on a factor of 3–4 times longer lifespan compared to conventional galvanizing, even in corrosive environments, making it very economical.

Function principle

Preferentially, rope anchors are emplaced on the upper edge of the rock slope. The rows of TECCO® mesh are fastened to a support rope connected to the anchors, and are hung over the rock slope. Rockfall events are controlled in this manner, coming to rest in the catchment zone. Depending on local conditions, the TECCO® rockfall drape is suitable for slopes from 5 to 100 m height and single events of up to several cubic meters.

Higher efficiency and tested protection

Careful product development along with extensive laboratory tests and field tests with rockfall events are the hallmark of these rockfall drapes.

TECCO®, the high-tensile strength steel wire mesh offers the best characteristics for rockfall drapes

The steel wire mesh is single twisted into meshes in the shape of rhomboids. The steel wire surface is extremely hard and resistant to mechanical stress, yet is not brittle. This means the steel wire mesh can stand up to impacts from falling blocks of rock without sustaining damage. This special wire is the result of a multi-step wire drawing process in its manufacture; precisely regulated tempering processes enable a crystalline structure that is optimal for wiredrawing. The TECCO® steel wire mesh is the end product: either 3 or 4 mm steel wire, single twisted into rhomboidal meshes in the Geobrugg production facilities.

TECCO® Green G65/3 ağlar şu özellikleri içerir

Single twisted meshes offer greater fl exibility and lower costs

• The three-dimensional rhomboidal structure means the mesh is less noticeable and adapts better to topographical circumstances.
•  Lower installation costs result because the TECCO® mesh can be constructed in 3.5 x 30 m rolls.
•  Rolls can easily be lengthened or shortened.           

2 3 4 Field and laboratory tests as the basis for proper dimensioning and sizing

Dimensioning foundations guarantee fl awless material performance

The demonstrations of the bearing resistance of the mesh have been ascertained in test series at the Bavarian LGA Regional Trade Institution (Landesgewerbeanstalt) in Germany and at the University of Cantabria in Spain. Tested were the pulling stress in both major directions with and without connection to adjoining rows of mesh; puncturing mechanism and the possible unraveling of damaged mesh. These independent test series with the TECCO® mesh made of high-tensile steel wires proved conclusively that no unraveling effect occurs.

1. University of Cantabria 
2. Puncturing test LGA Bavaria (D)
3. Drawing test with seaming rop ®
4. Drawing test with TECCO® 4 mm

Measuring

For proper dimensioning of rockfall drapes, three actions must be known:

1. Which forces are transmitted from the TECCO® mesh to the support rope and the anchor, and what does the connection look like? Demonstration test series A.
2. Which impact energies can the TECCO® mesh absorb? Demonstration test series B.
3. Which forces act through friction on the slope edge? The demonstration is project-specific. The foundations for these demonstrations were ascertained with the following test concept. They form the sizing foundations for rockfall drapes in terrains with different topographies.

Test series A - determining the forces on the support rope and anchor

The connections from the TECCO® mesh to the support rope and rope anchor were tested in a test framework (see figure) in 15 different test arrangements at Geobrugg‘s own Lochezen test facility. The force and deformation measurements yielded the following optimal connection combinations:

• The rope anchors are set near the seams of the contiguous rows of mesh.
• The TECCO® mesh is sewn taut to the support rope with a seaming rope.
• Seaming is especially loose in the anchor areas where the seaming ropes of the rows of mesh meet the seaming rope of the rows on the right and left.

These field-tested connections yielded the greatest possible force transmission and a low-cost installation.

1. Test framework Walenstadt (CH)
2. Test tensile force A = Measuring sensors  Z3 = Tensile force to tensile beam  Z4 = Tensile force to anchor
3. Deformation test of the support wire rope

Test series B - determining the energies in rockfall events

The test structure in a nearly vertical solid rockface in Geobrugg‘s own test facility.

The impact of a block of rock at an angle of 30 degrees into the TECCO® mesh was defined as the endangering rockfall event. Instead of an impact away from the rockface, free fall into the TECCO® mesh was selected in the test arrangement. In this test arrangement the rock blocks could be released more easily and the impact energies more exactly determined. Such a test arrangement reflects the actual conditions and reactions in field situations, though in mirror image.

The optimal connections determined in test series A were selected, with 3 rows of mesh were sewn together side by side and fastened to the support rope. The support rope was fastened with shackles to a steel construction. The border rope and a lower border rope anchored on both sides parallel to the support rope were connected with the rows of mesh. The impact energies in the ropes and anchors were measured with load cells and recorded.

Several large blocks of rock were thrown down from different heights at an impact angle of 30 degrees. The projectile energy was incrementally increased up to the tensile strength limits of G65 TECCO® mesh, both 3 mm and 4 mm wire diameters.

The resistance values thus measured and evaluated form the basis for the project-specific dimensioning.

Important note: Only for these tests, to measure the forces in a worst case scenario, a lower border rope was installed. In actual installations, this lower border rope is not used, as this can negatively influence the overall performance of the rockfall drape.

Corrosion protection: Only the best is good enough - because lifespan depends on it One more reason that makes TECCO® slope stabilizations very economical: the corrosion

Essentially we supply all steel components (posts, ground plates and U-brakes) hot-dip galvanized, the TECCO® mesh, the SPIDER® net as well as the ropes with GEOBRUGG SUPERCOATING® or GEOBRUGG ULTRACOATING®, the 3rd generation of our zinc/aluminium coating. This considerably improves the corrosion resistance of the wire: comparison tests with galvanized wires demonstrate a working life six to ten times longer for wires treated with ULTRACOATING®, and two or three times longer for those treated with SUPERCOATING®.

GEOBRUGG ULTRACOATING®: The intelligent type of coating

As with SUPERCOATING®, the wires first run through a zinc bath and afterwards a zinc/aluminum-bath. The result is an eutectic alloy with 5 % aluminum, 94.5 % zinc and 0.5 % of a special add-on. Thanks to this the smooth surface remains after being attacked by corrosion, since the corrosion leads to a reduction of the zinc layer and to the formation of an aluminum oxide layer. This guarantees the protected object an economical lifespan even in corrosive environments (roads, railways, industry, coastal and volcanic regions).

The coating is applied in a double dip procedure and final drawn. This results in a very compacted fine surface which gives a better corrosion protection compared to standard coated wires.

Requirements, Boundary conditions & Installation

What the rockfall drape can and cannot do

The TECCO® rockfall drape is deployed mostly on rock slopes. Rockfall events are thus controlled and deposited in the catchment zone. Other appropriate measures are needed to solve problems with the overall slope stability and slides in the surface environs. Strains on the drape, caused by continued weathering and surface changes, caught blocks of rock as well as large-surface deposits of snow and ice, can be absorbed effectively subject to suitable dimensioning of the system and its anchors.

Geobrugg, a reliable partner.

Our engineers and partners analyze the situation together with you and then, working together with local engineering firms, present their solutions. Painstaking planning is not the only thing you can expect from us, however; since we have our own production plants on four continents, we can offer not only short delivery times but also the best possible customer service right on your doorstep. To ensure your project runs smoothly, we deliver pre-assembled and clearly labeled system components right to the construction site. Here, we can also provide technical support if required – from installation right through to final acceptance of the structure.

Product liability

Rockfalls, landslips, debris flows, shallow landslides and avalanches are natural events and therefore cannot be calculated. For this reason, it is impossible to determine or guarantee absolute safety for persons and property using scientific methods. This means that, to provide the desired level of protection, protective systems must be monitored and serviced regularly and appropriately. In addition, events that exceed the system’s calculated absorption capacity may cause damage. The use of non-original parts as well as severe corrosion, such as might be caused by environmental pollution, can reduce the level of protection provided.