High-strength Slope Retention Systems

Size: px

Start display at page:

Download "High-strength Slope Retention Systems"

Barbra Lee
5 years ago
Views:

1 High-strength Slope Retention Systems

Trumer Schutzbauten - safety by competence Trumer Schutzbauten is your experienced and competent partner in terms of rockfall protection, avalanche protection and rock/slope stabilisation.

Unlike more conventional slope mesh systems that are passive measures which allow a slope to erode (e.g.

This is possible through the use of a highstrength mesh that is connected to a matrix of soil/rock anchors.

2 Trumer Schutzbauten - safety by competence Trumer Schutzbauten is your experienced and competent partner in terms of rockfall protection, avalanche protection and rock/slope stabilisation. Scientific research in perfect harmony with nature and the need for protection of mankind are the forces that drive the development and are the basis of the company s principles. Unlike more conventional slope mesh systems that are passive measures which allow a slope to erode (e.g. drape mesh), a slope retention system prevents erosion and mass wasting by retaining the masses in situ. This is possible through the use of a highstrength mesh that is connected to a matrix of soil/rock anchors. By securing the slope in this manner, a number of benefits become apparent: - slope maintains original geometry; - re-vegetation is possible; - dewatering of slope is uninhibited; - no catchment area/ditch required; - low maintenance due to lack of impacts on inside of mesh; - aesthetically more acceptable than other more invasive measures, e.g. gravity walls, shotcrete. Wire mesh slope retention systems offer comparable strength and functionality to conventional measures but are less intrusive. Systems are installed in the initiation zones of mass wasting and so mitigate the process and not the effect. Through a detailed geotechnical field investigation and subsequent static calculations, anchor spacing and the type of system required can be determined. Installation is generally quicker and more cost effective than other measures, depending on the geotechnical characteristics of the site. Since the need for a catchment area is eliminated, these systems are particularly important for tunnel portholes and other infrastructure in steep terrain. 2

High-strength slope retention systems are in wide use in Europe and are becoming a more common solution in North America and other parts of the world.

2 An approximately 1000 m rock slope with slope retention system. Through the re-stabilisation of the slope using mesh, natural revegetation is encouraged.

Supplemental bio-mats and seeding mixtures can also be applied all of which produces a safer slope that blends in with nature. Retaining wall reinforced using High Performance Netting.

3 High-strength slope retention systems are in wide use in Europe and are becoming a more common solution in North America and other parts of the world. They are used not only for the stabilisation of natural slopes, but also the fortification of existing structures or are incorporated into new ones. 2 An approximately 1000 m rock slope with slope retention system. Through the re-stabilisation of the slope using mesh, natural revegetation is encouraged. Furthermore, netting can accommodate pre-existing vegetation such as tree trunks with little effort. Supplemental bio-mats and seeding mixtures can also be applied all of which produces a safer slope that blends in with nature. Retaining wall reinforced using High Performance Netting. Slope retention systems by Trumer Schutzbauten are designed to meet the clients needs. Depending on the site characteristics and strength requirements, a large variety of net and netting products are available. Additionally, the orientation of the mesh, support cables, and cable connections can be arranged to suite virtually any condition. A historical retaining wall with High Performance Netting added to help stabilise the slope and structure. The following nets and nettings are available: Diameter (mm) Mesh (mm) Omega-Net to 185 High Perform x 50 Rectangular x 60 Rectangular x 50 Hexagonal x 100 Hexagonal x 80 Hexagonal x 70 Galvanisation Regular Heavy Zn-Al Note: rectangular and hexagonal netting is more suited for low strength applications. 3

High Performance Netting - the logical solution Strength, durability and flexibility are its dominant characteristics and are the key elements for a

High Performance Netting by Trumer Schutzbauten is the only wire mesh product on the market for slope retention systems that has 150 kn/m tensile

Furthermore, it was tested with the highest values during pull-through tests (68 kn) when compared to other products.

6 mm diameter wire, small mesh size (50 mm x 50 mm) and highest class of galvanisation (Class A according to EN 10244-2), the mesh is a very durable and

Due to its flexible nature, High Performance Netting can easily be fit to even the most challenging topography. Tensile strength test. Pull-through test.

4 High Performance Netting - the logical solution Strength, durability and flexibility are its dominant characteristics and are the key elements for a reliable slope retention system. High Performance Netting by Trumer Schutzbauten is the only wire mesh product on the market for slope retention systems that has 150 kn/m tensile strengths of the mesh in both horizontal and vertical directions. Furthermore, it was tested with the highest values during pull-through tests (68 kn) when compared to other products. With this said, and combined with its 4.6 mm diameter wire, small mesh size (50 mm x 50 mm) and highest class of galvanisation (Class A according to EN ), the mesh is a very durable and efficient alternative to more conventional products. Due to its flexible nature, High Performance Netting can easily be fit to even the most challenging topography. Tensile strength test. Pull-through test. Product Specifications Mesh Wire Roll Tensile Lengthwise 150 kn/m Strength Crosswise 150 kn/m Pull-through Strength 68 kn Number Horizontal 13 m -1 Vertical 13 m -1 Type Size Diameter Tensile Strength Weight Width Length rectangular 50 mm x 50 mm 4.6 mm N/mm 2 ~5.6kg/m m m 6m-10m High Performance Netting can be mounted in either the horizontal or vertical orientation due to its equal strengths in both directions. Low-energy rockfall catchment fences by Trumer Schutzbauten also use the High Performance Netting, which has been tested for impacts up to 167 kj (i.e. 545 kg traveling at 89 km/h). 4

Omega-Net - where nothing else will do Derived from rockfall and avalanche technology, this is the ultimate solution to high-strength needs.

The nets are extremely flexible and panel sizes can be suited to individual projects, making it ideal for highly irregular rock slopes.

The strands themselves are thick galvanised spiral ropes that - although meet at intersecting points - are not connected to each other, since no clamps are used.

5 Omega-Net - where nothing else will do Derived from rockfall and avalanche technology, this is the ultimate solution to high-strength needs. The Omega-Net by Trumer Schutzbauten is the solution to higher strength applications. Various rope diameters are used to construct the nets, starting at 4.5 mm with a mesh size of 100 mm. The nets are extremely flexible and panel sizes can be suited to individual projects, making it ideal for highly irregular rock slopes. The structure of the Omega-Net is unique, consisting of pre-formed waves and interwoven strands of high-strength rope. The strands themselves are thick galvanised spiral ropes that - although meet at intersecting points - are not connected to each other, since no clamps are used. The Omega-Net is a unique product that can easily fold together for transportation and installation. The Omega-Net is not only used for slope stabilisation but is also the primary interception structure for all of Trumer Schutzbauten s high-energy rockfall catchment fences and avalanche protection structures. Heavy rock stabilisation using Omega-Net. Product Specifications Slope mesh system securing tunnel portal for rail line. Panel Rope Mesh Horizontal 9m -1 Number Vertical 9m -1 Type elliptical Size 100 mm x 100 mm Diameter 4.5 mm Tensile Strength 1750 N/mm 2 Weight ~ 2.7 kg/m 2 Width made to order Length made to order Note: specifications are for the 4.5 mm diameter net. Please inquire for specifications of other nets. 5

An integral part of slope retention systems is the method of connection between the mesh and soil/rock anchors.

In general, they use a combination of corner spikes and welded-on pins to ensure optimum interlocking with the mesh.

Connection elements are designed to be compatible with standard anchor types.

For boundary conditions, a special Wire Pack Anchor is also available.

A typical roll weighs approximately 100 kg. View downslope of installation of High Performance Netting being installed by hand.

6 An integral part of slope retention systems is the method of connection between the mesh and soil/rock anchors. Plates used for connection vary in form and function. In general, they use a combination of corner spikes and welded-on pins to ensure optimum interlocking with the mesh. For those systems using bearing ropes, positive and non-positive couplings are available for both boundary ropes as well as interior ropes. Connection elements are designed to be compatible with standard anchor types. Furthermore, interior anchors can be drilled and set after or prior to the installation of the mesh. For boundary conditions, a special Wire Pack Anchor is also available. An example of interior anchors using a heavily galvanised spike plate for the coupling. Rolls of High Performance Netting shown after delivery. A typical roll weighs approximately 100 kg. View downslope of installation of High Performance Netting being installed by hand. Installation can be carried out by hand or using cranes or lifts as shown here. High Performance Netting and the Omega-Net are delivered in manageable sized packages. Adjacent panels are sewn together using a sewing rope. In the case of High Performance Netting, panels can be spliced together along the short side using an original wire strand, providing a seamless connection. A single strand of wire, which is supplied with every roll, can be corkscrewed between two adjacent panels to provide a seamless connection. 6

Wire Pack Anchors - flexibility where it counts An effective solution for where anchor forces are not inline with the loads.

In the event of loading, this causes the anchoring loop to bend where it exits the borehole.

Wire pack anchors consist of a bundle of parallel leading, contoured wires (diameter 6 mm) that are spread apart from one another at a distance of 1.0 to 1.

The wire bundle is characterized by rod-like rigidity during insertion into the borehole.

7 Wire Pack Anchors - flexibility where it counts An effective solution for where anchor forces are not inline with the loads. Wire Pack Anchors are used for anchoring bearing and retaining ropes in which the direction of the anchor does not correspond with cable forces. In the event of loading, this causes the anchoring loop to bend where it exits the borehole. Before loading After loading Wire Pack Anchors come in a variety of break loads designated by the coloured tip of the eyelet. Schematic showing the effect of loading. Wire pack anchors consist of a bundle of parallel leading, contoured wires (diameter 6 mm) that are spread apart from one another at a distance of 1.0 to 1.5 m from the head of the anchor and, at the same time, are spaced from the bore hole wall by means of a spacer (outside diameter 65 mm). This results in optimum adhesion to the cement mortar. The wire bundle is characterized by rod-like rigidity during insertion into the borehole. The wire bundle loop, covered with a corrosion-proof steel tube, may be angled up to 45 around a rock edge without reducing the wire bundle anchor's breaking force. Various aspects of the Wire Pack Anchor make it a unique solution, including the wire strands and spacer (top and bottom left) as well as the grouting tube and available double corrosion protection (bottom right). The cement-filled, corrosion proofed steel tube ensures the wire bundle's optimum protection against corrosion in the loop area. Inside the borehole, the wire bundle is protected against corrosion by the cement mortar delivered through the grouting tube. To increase corrosion proofing, the wire bundle may be placed inside a corrugated PE jacket tube, which has been pre-injected with cement mortar at the plant or is directly filled inside the borehole. The following anchors are available: Number of wires Cross section Mass Yield load Break load (Ø 6mm) (mm²) (kg/m) (kn) (kn) WPA WPA WPA WPA WPA WPA

032010 Weissenbach 106 5431 Kuchl Austria Tel.: +43 6244 20325 Fax: +43 6244 20325-11 E-mail: office@trumer.

8 Weissenbach Kuchl Austria Tel.: Fax: Production: Handelsstrasse Obertrum am See Austria West Broadway Vancouver, BC Canada V5Z 1K5 Tel.: (604) Fax: (604) canada@trumer.cc

Slope Stabilization: Slope Retention Systems

Slope Stabilization: Slope Retention Systems Slope Mesh - draped verus anchored systems Draped mesh systems serve a different purpose than slope retention systems (anchored mesh): where a draped mesh is