512 Ground investigations, contracts and pile testing
construction and the Engineer/Designer should state the form in which they will be provided
including the level of the platform in relation to the pile commencing surface and cut-off level.
Underground servicesand obstructionscan be a contentious item. Under traditional ICE
contracts it is normally the Engineer’s responsibility to locate all known buried services and
other obstructions to pile installation. It is unfair to the Contractor for the Engineer to disclaim
all responsibility for the accuracy of the location plan, and to expect the Contractor to accept
the consequences of damage to services. However, the Engineer has the right to expect that
the Contractor will not push on blindly with the piling work with complete disregard for the
safety of the operatives or the consequences of damage. The Contractor is expected to keep a
close watch on the conditions as the piling progresses and make enquiries as to the likely pres-
ence of further underground obstructions. The consequential damages can be very severe if,
for example, a water main is broken which floods the running lines of an underground
railway. Hence, the clause in the conditions of contract covering underground obstructions
needs to be carefully worded to be fair to the interests of all parties. For example, it may be
an express condition of the contract for piling in an urban environment for the Contractor to
provide a consultant services engineer to carry out investigations prior to piling.
Compliance with the Construction(Design and Management) Regulations 1994(CDM),
the Health and Safety at Work Act 1974and the Environment Protection Acts(EPA) involves
all parties to the contract even if not expressly stated. The piling contractor may be the first
and only party on the site initially, requiring him under the CDM regulations to undertake
the statutory duties of the ‘principal contractor’, and possibly the ‘planning supervisor’and
‘designer’all as defined. The statutory regulations under the EPA control the disposal of
arisings from bored piles and waste drilling fluids, and the Health and Safety regulations
cover all aspects of construction from protective clothing, lifting and hoisting appliances to
access into excavations and welfare facilities.
There is usually an obligation for the Contractor to operate a Quality Management System
(conforming to BS5750/ISO9001) within the company and to produce a Project Quality Plan
as a means of assuring the Employer that the required standards for the works have been met
through traceable documentation. The System and the Plan will be subject to certification
and audit either by an independent third party or by the Employer, but self-certification by
the Contractor to assure compliance with the specification may be acceptable – except for
laboratory testing. Surveillance and intervention by the Engineer or the Supervisor will be in
addition to the Contractor’s demonstration of conformance under his plan.
Responsibility for risk assessmentsto identify the hazards (risk events), probability of a
risk event occurring, ensuing injury, damage and loss, and any general uncertainties will ini-
tially fall to the Employer’s team as part of the project feasibility study. The piling contrac-
tor will have to advise the Employer of potential hazards involved in the particular method
proposed. In the NEC3 contract a ‘risk register’, which contains descriptions of the risks and
the actions to be taken to avoid or reduce the risks, is included in the Contract Data.
11.2.2 Piling specifications
The Institution of Civil Engineers’Specification(2.5)details items which should be included
in the ‘Particular Specification’for a piling contract. These include stating responsibility for
design, performance criteria to be applied, requirement for additional ground investigation
as well as routine matters on site location, personnel, and so on. It also states that all
materials and workmanship ‘shall be in accordance with the appropriate British Standards,
Codes of Practice and other specified standards’and specifications should quote the relevant