I have looked at the documents for bidding for the Hope Canal, in particular the 3-Door Head Regulator and am surprised that the Soil Investigation Report is not part of the documents but only available at the pre-tender meeting for viewing. Contractors have to make their assessment of the soil conditions to be encountered and no claims for extras will be entertained.
In addition there is no item in the Bill for temporary works as well as for dewatering, and bidders are asked to include same in other rates in the Bill. Both these items are quite expensive and in my opinion it is highly irregular that they are not being included in the Bill of Quantities. Visiting the site and inspecting the surroundings as required by the contract would not apprise an unsuspecting bidder of what he will encounter during construction.
Driving over 300 timber piles nearly 100 ft long as well 30ft long steel sheet piles would be extremely challenging. Since the regulator is located close to the EDWC, dewatering the site may require a well-point system to depressurize the head to enable construction to proceed. Disposal of the ground water extracted could also pose a problem.
The soft pegasse soil would make construction very difficult.
From my knowledge there are no contractors in Guyana capable of carrying out this type of dewatering work. In addition to the above, the structure does not appear to be designed for uplift pressures, only for downward loads. It should be noted a similar structure built on similar soil conditions floated away during construction of the Boeraserie Scheme several years ago.
This letter is written based on my experience working in the area and not to dissuade bidders from tendering, but to let them be aware of the potential problems that lie ahead during tendering and construction.