Terrafix Erosion Control Blocks ®

Terrafix is an interlocking environmentally acceptable element, made of high strength concrete. It was specifically designed to provide a flexible lining where cost-effective protection against wind and water erosion is required. The blocks are available in three different thicknesses and can be laid in a variety of configurations to suit most site conditions.

This makes it the ideal product to help combat rapid degradation of rivers and streams. Terrafix can help prevent soil being eroded away, while still being permeable enough to help preserve ground water reserves and biodiversity.

Click here for examples.

The elements are made out of durable concrete and therefore can safely be used in most saline or polluted conditions. Units interlock laterally and offer a secure yet flexible lining. They are highly permeable but can be made impermeable by either placing an impervious membrane underneath the blocks or by grouting the structure with concrete or mastic. The system offers one of the most cost-effective and speedy erosion control methods and provides a perfect regime for establishing vegetation. Stability improves as vegetation takes root. Terrafix units are available in three thicknesses, namely 100, 120 and 150 mm. They can be laid in different configurations ranging from 4 blocks to 10 blocks per square metre. In this way, over-design and overspending is avoided.

Block Terrafix 100 Blocks/ m² (measured on the face) 4-10 Block mass/kg 13 Block infill volume/ m³ 0.004 Ave. constructed mass kg per m² of area 190 Block wall thickness 40 Block Terrafix 120 Blocks/ m² (measured on the face) 4-10 Block mass/kg 16 Block infill volume/ m³ 0.005 Ave. constructed mass kg per m² of area 235 Block wall thickness 40 Block Terrafix 150 Blocks/ m² (measured on the face) 4-10 Block mass/kg 21 Block infill volume/ m³ 0.006 Ave. constructed mass kg per m² of area 300 Block wall thickness 40

Variations of patterns possible with the Terrafix block

APPLICATIONS

Embankments and slope stabilisation:

Road and railway bridge abutments can be protected against wind and water erosion with good effect and erosion problems or aesthetic considerations of embankments and cuttings can be effectively countered with the TERRAFIX system. Protection is offered to a varying degree by allowing the choice of appropriate laying patterns and thicknesses.

Riverbank and Shoreline Protection:

Riverbank and shoreline protection	Slope protection and rehabilitation

The system lends itself to providing an effective lining for river banks, canals, resevoirs and lakes. Under such circumstances it is essential to design a suitable filter underneath each structure in order to prevent leaching of fines. Woven or non-woven geotextiles are considered to be most suitable .

Erosion at the toe of the bank is prevented by continuing the lining to below anticipated depth of scour. Below the waterline, cells should be filled with coarse material and with topsoil above normal waterline. Graded rock or woven/non-woven geotextile filters are to be provided where necessary, to prevent leaching of fine soil particles.

Stormwater Control and Spillways:

Dams and Spillways	Storm water control

The elements are used for lining dam spillways and sloping weirs, storm water attenuation ponds or downstream aprons. They are also ideal for lining water courses of varying sizes from small ditches to large canals. In designing such structures a roughness coefficient of 0.04 (CERC 1984) has to be assumed.

DESIGN CONSIDERATIONS

A feasibility study into the hydraulic applications of the TERRAFIX system by the division of Earth, Marine and Atmospheric Science and Technology of the CSIR has revealed very positive characteristics. A copy of this report is available on request.

Please note: Information contained in this brochure is furnished as a guideline only. The responsibility for correct utilisation, design and construction shall rest with the controlling engineer or contractor. For best results and technical advice, contact our recommended contractors.