ABSTRACT
SPECIAL STRUCTURES DESIGNED BY THE CONTRACTOR Notes This section envisages the following types of structure which may be required to be designed by the Contractor based on stipulated performance criteria: * Buried structures * Earth retaining structures * Environmental barriers * Under bridges up to 8 m span * Footbridges * Piped culverts * Box culverts * Drainage exceeding 900 mm diameter * Other structures Naturally, this work cannot be catered for directly in this section and will require the preparation of a sketch solution and approximate quantities to allow pricing using the various other Unit Costs sections as well as the Approximate Estimates section. An allowance must be added to such an estimate to cover the Contractor's design fee(s) and expenses.
