diaphragm and settlements at the working load would be excessive. It is also ineffective in
clays or where clays are overlying the coarse soil bearing stratum. A hole is necessary in the
diaphragm for release of water pressure in the soil plug and to allow expulsion of silt.
Stresses on the underside of the diaphragm are high during driving and radial stiffeners are
needed (Figure 8.18). The pile wall below the diaphragm must be sufficiently thick to
prevent bursting by circumferential stresses induced by compression of the soil in the plug.
8.4 References
8.1 BRITISH STANDARDS INSTITUTION. BS6349-1: 2000 Maritime structures. Code of practice for
general criteria, BSI, London, 2000 (in revision 2007).
8.2 BROADHEAD, A. A marine foundation problem in the Arabian Gulf, Quarterly Journal of
Engineering Geology, Vol. 3, No. 2, December 1970, pp. 73–84.
8.3 WIEGEL, L., BEEBE, K. E., and MOON, J. Ocean wave forces on circular cylindrical piles,
Proceedings of the American Society of Civil Engineers, Vol. 83, No. HY2, 1957, pp. 1199/1–36.
8.4 REID, G. O. and BRETSCHNEIDER, C. L. Surface waves and offshore structures. The design
wave in deep or shallow water. Storm tide and force on vertical piling and large submerged
objects. The A and M College of Texas Department of Oceanography, October 1953
(unpublished).
8.5 DAILEY, J. W. and STEPHEN, S. C. Characteristics of the solitary wave, Transactions of the American
Society of Civil Engineers, Vol. 118, 1953, pp. 575–81.
8.6 BRETSCHNEIDER, C. L. A theory for waves of finite height, Proceedings of the 7th Conference on
Coastal Engineering, Vol. 9, 1961, pp. 146–83.
8.7 NEWMARK, N. The effect of dynamic loads on offshore structures, Proceedings of the 8th Texas
Conference on Offshore Technology, Houston, Texas, September 1956, Paper No. 6.
8.8 Shore Protection Planning and Design, Technical Report No. 4, 1966, US Army Coastal
Engineering Research Centre, Part 2, Chapter 4, pp. 278–96.
8.9 MORISON, J. R., O’BRIEN, M. P., JOHNSON, J. W., and SCHAAF, S. A. The force exerted by surface waves
on piles, Petroleum Transactions, American Institute of Mining and Metallurgical Engineers,
Vol. 189, TP 2846, 1950, pp. 149–54.
8.10 Steady pounding of North Sea gas platforms, Ocean Industry, Vol. 10, No. 8, 1975,
pp. 64–71.
8.11CHAPPELAAR, J. G. Wave forces on groups of vertical piles, Journal of Geophysical Research,
American Geophysical Union, Vol. 64, 1959.
8.12KORZHAVIN, K. N.Action of ice on engineering structures, USSR Academy of Science, Siberian
Branch, 1962. (Translated by US Army Cold Regions Research and Engineering Laboratory,
1971).
8.13TRYDE, P. Ice forces, Journal of Glaciology, Vol. 19, No. 2, 1977.
8.14CROASDALE, K. R.Ice forces on fixed rigid structures, US Army Cold Regions Research and
Engineering Laboratory, Special Report No. 80–26, 1980.
8.15BROWN, T. G. Ice loads on the piers of the Confederation Bridge, Canada, The Structural
Engineer, Vol. 78, No. 5, 2000, pp. 18–23.
8.16BONNETT, D. Wind turbine foundations – loading, dynamics and design, The Structural Engineer,
Vol. 83, No. 3, 2005, pp. 41–45.
8.17FFRENCH, R., BONNETT, D., and SANDON, J. Wind power – a major opportunity for the UK,
Proceedings of the Institution of Civil Engineers, Vol. 158 (Special Issue 2), 2005, pp. 20–27.
8.18 Regles BAEL 91 (Béton Armé aux Etats Limites), Modifée 99, publ Eyrolles, May 2000.
8.19 Recommended practice for planning, designing and constructing fixed offshore platforms,
American Petroleum Institute, Publication RP2A, Washington DC, 1987.
8.20 Recommended practice for planning, designing and constructing tension leg platforms,
American Petroleum Institute, Publication RP2T, Washington DC, 1993.
424 Piling for marine structures