The International Federation of Consulting Engineers (Fidic) and the International Tunnelling and Underground Space Association (ITA-AITES) have teamed up to publish a new form of contract for tunnelling and underground works.
The new contract, The Emerald Book, will set out new conditions of contracts for underground works.
A spokesperson for Fidic said the new contract was in response to underground construction being a fast-growing market sector due to the increasing demand for use of underground space for infrastructure.
Underground construction is highly dependent on the geological, hydrogeological and geotechnical properties of the ground, which had a “defining influence” on the methods required for the successful implementation of the works.
In addition, the spokesperson said the difficulty in predicting ground behaviour and foreseeable conditions implied an inherent uncertainty in underground construction which gives rise to unique contractual risks regarding construction practicability, time and cost. It is these risks which are being addressed in the new form of contract.
The contract was drawn up by a joint task group of representatives of Fidic and ITA-AITES who identified issues that the new standard form of contract should address to promote equitable risk allocation and the effective dealing with conditions typically unforeseeable, in such projects.
Fidic contracts committee chair Zoltán Záhonyi said: “Working together, Fidic and ITA-AITES have created a contract that we believe, and hope will command the respect and authority of the tunnel engineering and construction sector and that both clients and contractors can use with confidence.
“The new Emerald Book addresses several critical areas that should lead to the smoother running of contracts in the growing tunnelling and underground works sector.”
ITA-AITES president Tarcisio Celestino added that the new contract would bridge an important gap.
“Despite all the technological developments of equipment and techniques in the field, many underground construction projects end up unsuccessful because of contractual disputes,” he said. “The book brings together the result of the expertise and respectability of ITA-AITES and Fidic in the fields of contracts and specificities for underground constructions.”
Key issues which have been specifically addressed in the new contract:
- Allocation of risk.
- Disclosure of all available geological and geotechnical information.
- Inclusion of a contractual geotechnical baseline.
- Inclusion of a tailored “Unforeseeable Physical Conditions” clause.
- Implementation of a ground classification system and of supporting particular conditions that properly reflect the effort of excavation and stabilisation.
- Time for completion is largely influenced by ground conditions.
- Provision of a flexible mechanism for remuneration according to ground conditions, foreseen and unforeseen.