GTF subcontractor Sovereign has performed the test grouting program at Panel 109A on March 1st, 2011 through March 3rd, 2011 as directed in REC-1862.
The purpose of the trial was to reduce the flow of water into the open-cut by at least 75%. After completion of the injection of colloidal emulsion (and cementitious grouting of the concrete collection box), the pipes collecting the water from the interface of Panel 109A yielded negligible inflow. Based upon these results, MTACC considers the trial program to be successful and that Sovereign, under the supervision of GTF, have met their technical obligations of the trial by reducing the groundwater inflow to within agreed quantities. MTACC will release payment for Sovereign immediately as part of Bid Item 15 as part of payment application #19. GTF’s support costs were to be submitted as required in REC-1862. These costs have yet to be submitted.
Proposed Subsequent Work (Groundwater Inflow Mitigation) to be Carried Out by Sovereign:
MTACC would like to engage Sovereign (via GTF) to carry out further work to mitigate groundwater inflows at other locations around the open-cut. In this regard, MTACC requests the following:
- A site walkthrough and joint identification of locations should be conducted by GTF and MTACC. GTF shall then develop a technical plan that will include an explanation of inflow type and assessment of flow rate for the locations identified during the walkthrough.
- GTF/ Sovereign are to prepare a proposal for the works which as agreed on the site walkover carried out on March 4th, 2011 will be based on a daily rate and shall include Sovereign’s daily costs, GTF’s support costs, anticipated material costs and any other costs that need to be applied for inclusion in the proposal costs.
- The proposal is to include a schedule of work activities detailing when Sovereign will be available (on-site) to execute the work and the start time and tentative duration of each location identified in point 1 above. The schedule needs to be created such that Sovereign’s work will not impact on other GTF activities or the proposed Milestone 1A / 1B transition. Should they do so, such impacts if unavoidable should be identified in the schedule and quantified if they are considered to have cost implications.
We look forward to receiving the GTF proposal and seeing Sovereign retum to site to undertake further groundwater inflow mitigation works.