The realignment of SH88 north of Frederick St in Dunedin, intended to create a corridor around the new Forsyth Barr Stadium at University Plaza in time for the Rugby World Cup, is now complete. The official opening of the stadium took place on 5 August with a blessing performed by local iwi and Minister of Transportation, Stephen Joyce and Mayor David Cull in attendance.
The realignment of SH88 has seen the roadway raised up to 4m, adjacent to the new stadium, and retained with a segmental retaining system, which posed a few challenges for the installation of the guardrail system on the roadway above.
“This particular site required the Nu-Guard® 31 Guardrail System to be installed behind the retaining wall which posed considerable engineering challenges for all concerned,” said Ian Rowland, Area Sales Manager – South Island for CSP Pacific. “We worked very closely with Hawkins Infrastructure on this project to ascertain the loading on the retaining wall for the correct installation of the guardrail.”
“With the guardrail being installed into retained embankment along the top course of the wall, we had to ask the question, ‘what sort of loading could we expect on the wall in a worst case scenario?’” said John Cross, Project Manager for Hawkins Infrastructure. “We obtained the original test results on Nu-Guard® 31 from the USA and with CSP Pacific and local engineers BDO’s assistance we then were required to make modifications to the wall and how the Nu-Guard® 31 would be installed.”
With the blocks filled with concrete, longer geogrids installed and both vertical and horizontal reinforcing inserted into the wall the calculations required the post spacings of the guardrail be shortened from 1905mm to 955mm to ensure that Nu-Guard® 31 performed to the highest level to ensure motorist safety.
“It was a very tricky job as we also had several places the Nu-Guard® 31 transitioned to Thriebeam™ on the bridge and back to Nu-Guard® 31 again,” adds John.
“Ian and CSP were great on this install. Ian made several trips to the site and helped with the redesign. It was certainly a very challenging task but thankfully we finished on schedule. With the Rugby World Cup just weeks away the pressure was on but we came through on time with the help of Ian and the team at CSP Pacific.”