Mackay's Road Crossing to Peka Peka, Wellington

Contractor

Logicamms

Client

Vector

Location

Wellington, New Zealand

Products Used

Platipus S8 Pipe Kits

As part of a major state highway upgrade, a 300mm gas pipeline needed to be laid through sandy soils that were prone to a high water table and liquefaction. This raised the issue of the buoyancy of the pipeline under saturated conditions, and the need to ensure minimal movement to maintain the structural integrity of the system. A permanent buoyancy control solution was required that could be installed quickly and efficiently to keep pace with the project time line.

Design

Platipus Anchor Buoyancy Kits can be designed to address a wide range of situations. Suitable in most displaceable soil conditions, the anchors are driven below the pipeline on either side and a webbing and buckle system used to secure the pipeline without damage. For this project Platipus S8 Pipe Kits with unique buckle and strap system were installed at 15m centres along 2,850m of pipe.

Installation

In order to achieve good loads the S8 anchors were driven 5m deep, through sand into a layer of gravel, and then locked in the gravel layer. Each anchor could then be proof tested immediately to give assurance to the designers that the required loads were being met. The whole installation process was streamlined by the use of specialist Platipus Installation Tools, and training from the Cirtex site support team.

The products used provided the following benefits to the project: