Atteris conducted a review of all design and construction documents related to the Goulburn River HDD scope. The objective was to verify the HDD design and provide observations on the HDD construction operations. As part of the design verification, the following aspects were covered:
Based on the above, Atteris provided a view of the construction aspects considering the proposed design and construction procedures. During the review, it was found that the design profile was substantially deeper than the borehole depths resulting in more than half of the profile lying in a formation where no data had been gathered. Should a gravel layer have been present, this could have resulted in instability leading to collapse during the pull-in operation as well as linepipe coating damage. Atteris also attended the HDD construction operations and provided a list of observations in order to optimise future HDD operations for the Client.
