Kaikōura SH1 - SR10

The Kaikōura M7.8 Earthquake caused widespread damage to the road and rail corridor 20 km North and South of the Kaikoura town ship. Over 40 major slips inundated the road and rail with over 750,000 m³ of material form source zones up to 500 m above sea level.  The highly fractured Grey Wacke meant frequent future rockfalls were expected. The rockfall frequency and near vertical slope with no shoulder at SR10 created the requirement for a system that protected the road without encroaching onto it, was quick to install and requires minimal future maintenance. The slope on average is  80-90 degrees with the project being the final and most complex of the NCTIR rockfall protection systems.

A 104 m long self cleaning canopy (SCC-500) was installed at SR10. The self cleaning canopy was selected due to it's self cleaning ability and being able to withstand multiple rockfall impacts up to 500 kJ prior to requiring maintenance. The system has 13 posts ranging from 10-15 m in length with an upslope net length of between 12-26 m. The posts were anchored at 6 m high above the road with a 15 degree post inclination. The primary nets utilised high tensile (1770 MPa) ROCCO ring mesh with a secondary TECCO 65/3 for aperture control.  The structure has a support rope separation at post 6 to enable a split construction and a more efficient installation.  Type III flex heads were installed to transfer the off axis load back to the Gewi 32 anchor bar and a gap fill kit was installed to ensure  100 % system coverage. An active TECCO 65/3 system was installed in several areas below the canopy to mitigate the lower rockfall hazards. The system was installed using a combination of helicopters, cranes, Hiab's, scissor lifts and human power.