Pile Driving and Installation.

1 Steel pile installation tolerances
Information on tolerances that are achievable using commonly available pile driving
equipment and methods is quoted in the Institution of Civil Engineers publication

Specification for piling and specifications issued by the Federation of Piling
Specialists, the CEN Standard EN 12063 Execution of special geotechnical works – Sheet-pile walls, and the TESPA publication Installation of steel sheet piles.

Table 29.3 is included in the TESPA publication and represents tolerance levels for sheet piling which should not be too onerous to achieve but will give results which are visually acceptable – an important feature for permanent exposed sheet piling.

Steel pile driving tolerances (TESPA)
Steel pile driving tolerances (TESPA)

Accuracy of alignment will also be affected by pile stiffness, the driving equipment, and the experience of the workforce.Use of pile guide frames,which are often formed from universal beams aligned with their webs horizontal, will ensure that good alignment of the sheet piles is achieved.

2 Environmental factors: noise and vibration prediction

Increasing attention has been directed to environmental factors with regard to driven piles in recent years. Although the duration of the piling contract may be short in comparison with the whole contract period, noise and vibration perception may be more acute during the piling phase. Human perception is very intolerant of noise and vibration or shock transmitted through the ground, and tolerance requires careful prior education of the public. Efforts made to advise the public and to plan the precise times of driving carefully can reassure those likely to be affected in the vicinity of a pile installation and can result in the necessary cooperation.

In the UK, the Control of Pollution Act (1974) provides a legislative framework for, amongst other things, the control of construction site noise. The Act defines noise as including vibration and provides for the publication and approval of codes of practice, the approved code being BS 5228. Part 4 of the code deals specifically with piling noise. This code was revised in 1992 to include guidance on  vibration.

Two relevant documents include the TRRL Research Report RR53  Ground vibration caused by civil engineering works, and the British Steel publication Control of vibration and noise during piling.

The SCI publication Specifiers’ Guide to Steel Pilingalso contains useful advice. BS 6472 deals specifically with evaluation of human exposure to noise and vibration in buildings.

2.1 Noise from piling operations

Pile driving is perceived to be an inherently noisy operation because impact-based methods of installation have historically been used.Typical data on noise levels produced by piling operations have been published by CIRIA Report No. 64 Noise from construction and demolition sites – Measured levels and their prediction.

These are discussed and interpreted in CIRIA Report PG9 Noise and vibrations from piling operations. It is important to note that modern pile installation equipment such as the noise-free pile jacking machines will not be included as they post date these publications.

Impact driving of steel sheet piling is often noisy since the operation involves steel-to-steel contact. In areas where severe restrictions are placed on noise levels, pile vibratory or jacking equipment should be used.
Such machines emit a different frequency and lower level of noise which may be acceptable, and recent advances in noise reduction technology can ensure that the noise from the auxiliary power pack is also lowered.

2.2 Ground vibrations caused by piling

It is widely recognized that noise and vibration, although related, are not amenable to similar curative treatment. In the main, noise from a site is airborne and consequently the prediction of noise levels is relatively straightforward, given the noise characteristics and mode of use of the equipment. On the other hand, the transmission of vibration is determined largely by site soil conditions and the particular nature of the structures involved. General guidance can be derived from the study of case histories of similar situations. Useful references on the subject of ground vibrations are provided by CIRIA Technical Note 142 Ground-borne vibrations arising from piling, the publication  Dynamic ground movements – Man-made vibrations in ground movements and their effects on structures, and BRE Digest No. 403 Damage to structures from ground-borne vibration.

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