29 September 2007

The Wanganui office of Opus International Consultants and HEB Smithbridge Contractors recently received the Major Project Award at the recently announced 2007 New Zealand Roading Excellence Awards.

The prestigious Shell Bitumen Major Projects Award was made in recognition of the work undertaken by Opus engineers and planners for the initial site investigations and scheme assessment, design, resource consents, environmental planning, public consultation and construction supervision of the previously notorious stretch of SH1 at Hihitahi, approximately halfway between Taihape and Waiouru.

HEB Smithbridge was recognised for their efforts in the construction of the project, as were Transit New Zealand for their partnering approach as the client.

The Opus project team, led by Wanganui based civil engineer, Bob Smith, faced tremendous obstacles in planning the realignment of the highway due to the topography and diverse geology of this area known as Hihitahi Bluffs.

“The old 1.4km section of the highway was unduly winding and was often in heavy shade - resulting in the road surface icing up in the winter for long periods,” said Bob Smith.  “There were also very poor lines of sight for drivers, and this, along with the ice had resulted in a number of accidents over the years.”

“The geotechnical work we did played an important role in addressing slope instability and the bridge abutments had to be mechanically supported on stabilised reinforced earth walls.  In addition, the piles that were located on the slopes had to be isolated from potential earthquake movements.”

The project team also gave very careful consideration to a pristine trout spawning river (the Hautapu River) that also provides Taihape with its main water supply.

“We had to carefully plan the realignment as the design for the new section of highway passes over this river, through DOC administered scenic reserves and a number of archaeological and historically important areas,” said Jenny Harrison, Opus planner for the project and manager of the Wanganui office of Opus.  “We had to be careful that none of this was interfered with and was preserved.  HEB Smithbridge did an outstanding job ensuring that any impacts on the Hautapu River and the scenic reserves was kept to a minimum”.

Along with the realignment, three new bridges were also designed for the development by Opus.  The bridges carry the new section of the highway over the river and away from the bluff face.  This specialist work was done by the Wellington office of Opus, where their civil design team provided the geotechnical and structural design for the bridge foundations, bridges and bank excavations.

Construction work, which was led by Darren Bentham of HEB Smithbridge, was completed in sometimes very difficult weather conditions, with snow and ice covering the ground and often at minus degrees.  Darren was a key figure in ensuring the project was an award winner, managing the work on site and making sure it progressed smoothly and getting it completed five months ahead of schedule and under budget.

The Award judges said that the project was an excellent example of how road realignment could achieve road user needs while at the same time enhance environmental and community values.

“Consultation and communication with the many stakeholders resulted in a project which has been praised by all those involved - Transit New Zealand, as the client was delighted with the outcome and motorists are now enjoying the significant difference the realignment has made.” said Jenny Harrison.  “The realignment had been on the drawing board for some forty years with a number of options planned, but funding only became available for the project in 2004.”

The project was also awarded the 2007 New Zealand Planning Institute Project Award several months ago.

For further information please contact:

Jenny Harrison
Wanganui Office
Opus International Consultants
Tel: 027 484 4529