Use of contract unit prices for fair and reasonable payment of changes in baseline quantities for tunnel construction

摘要

We seem to have evolved into a situation where changed conditions is at the nexus of any and all claim situations in tunnel construction. The writer would like to postulate that there is no such thing as a changed condition for an entire contract, but rather every contract has varying conditions within the contract limits, especially for longer tunnels. Proceeding from the above postulate, it follows that there must be a full articulation and interdependency between: 1. The Geotechnical Report Baseline (GBR) and the .... 2. Measurement and Payment sections of the Specifications and the .... 3. General Specifications, especially the variable quantity clause(s) and the .... 4. Plans and the .... 5. Bid Schedule which will set appropriate lump sums (including the GBR quantities) or GBR quantities with bid unit prices. All changes from the GBR quantities will be paid for as directed (by the owner or his authorized representative) additional work at the directed additional work bid unit prices with stipulated minimum unit prices in the Bid Schedule. The bid directed additional unit price and bid quantities will be used for purposes of bid comparison only! Note that the stipulated minimum unit prices will prevent bid unbalancing by the Contractor and assure inclusion of money in the bid for additional payment, if owner directed additional work for changes in the GBR quantities is necessary. Also, note that directed additional unit price work may not be a function of only quantities, but time, as well. Some specific examples are cited below: 1. grouting - if at the face ( paid as owner directed delay, i.e. per crew and/or rig hour or shift plus unit price for volume injected); if from surface (paid for volume injected) 2. boulders - to be paid for as owner directed delay, i.e. per crew and/or rig hour or shift basis.