Ground investigations, contracts and testing 511loading tests, both on preliminary and working piles. While the Contractor is responsible for
selecting the type, diameter and penetration depth of the piles, calculations to justify these selec-
tions are required to be submitted for the approval of the Engineer. The statement concerning
working loads on columns, walls or individual piles should make it clear as to whether or not
the loads have been factored in compliance with Eurocodes or other structural codes of practice.
Method 3 is satisfactory in most respects provided that tenders are invited only from those
firms that have the necessary experience. It is usually stated in the tender invitation or it is
implied that the Contractor assumes responsibility for all aspects of the piling work. This
would include accepting liability for unforeseen variations in the ground conditions and the
possibility of having to increase substantially the penetration depth, or increase the number
of piles or even to abandon a particular system. The Contractor is usually responsible for
deciding whether or not load testing is required and the criteria for deciding successful
performance under test loading. However, the insurers providing the Contractor with the
essential warranty for his work and the Employer with cover for the structure may need to
be involved in the decision. As the design and construction rules in EC7 are adopted, the
Employer and Contractor will have to demonstrate that the pile design is related to static
load tests and, as noted in Section 11.4, testing will be mandatory in certain conditions. The
intention of Method 3 contract arrangements is to prevent unforeseen ground conditions
leading to claims by the Contractor, but it is incumbent on the Employer to ensure that all
information available at tender stage is passed to the Contractor, including any expert inter-
pretations of ground conditions obtained. It is in the interest of all parties that the Contractor
be allowed access to the site to carry out any additional investigations deemed necessary.
The Engineering and Construction Contract(11.16)aims to be simpler and more flexible
than other standard forms mentioned. For example, it gives more than 20 options for the
Employer to build up a contract to suit individual requirements; it allows for design respon-
sibility to be carried by either the Employer or Contractor depending on which party has the
competency. The traditional Engineer’s role has been removed and replaced with a ‘Project
Manager’having defined duties including acting as the Employer’s agent, issuing instructions
and certifying payments, and a separate ‘Supervisor’with duties for testing and inspecting the
works. Disputes are referred directly to a nominated Adjudicator.
The responsibility for providing information should be clearly defined in all the forms of
contract mentioned. However, the provision by the Employer through the Project Manager
of ‘additional information’, not in the contract Works Information but necessary for the
Contractor to complete the works, is only an implied term under NEC3 forms of contract. It
may therefore fall to the Contractor to fill in gaps in this case. Some items of information
and responsibility which should be clarified in the contract are as follows:
All relevant details of ground investigationsundertaken on behalf of the Employer before
inviting tenders for the piling. Geological data and interpretations may be excluded by
the Employer from the main contract Site Information under a NEC3 contract and only be
available as ‘reference’data – with implications for contractual Compensation Events. The
piling contractor should be aware of the need for additional ground information either prior
to tendering or following award of a contract in such circumstances.
The facilitiesprovided by the main contractor, or those to be included in the piling contract,
should be stated. These include such items as access roads, hardstandings for piling plant,
storage areas, fencing, watching, lighting, and the supply of electrical power and water.
Hardstandings (working platforms)(3.20)for large piling plant may need to be of substantial