Foundation engineering for deep water platforms (In Norwegian)

63A from model tests are presented as polar bearing capacity diagrams and are compared with theoretical values. The thickness of the clay layer on sand has a significant influence for single piles and pile groups. 862198 Elastic settlement of arbitrarily shaped foundations embedded in half-space. Technical note Gazetas, G; Tassoulas, J L; Dobry, R: O’Rourke, M J Geotechnique V35, N3, Sept 1985, P339-346 An analytical expression is developed for estimating the vertical elastic settlement of arbitrarily shaped rigid foundations embedded in a reasonably uniform and deep soil deposit, modelled as a homogeneous half-space. The expression encompasses the wide variation in the type of contact between foundation sidewalls and surrounding soil, between the extreme cases of complete perfect contact and of no contact at all. The proposed algebraic expressions are curve fits of the analytical data and hence accuracy of settlement may be no better than lo-20%. 862191 Research on piled foundations - historical review and future Wardle, I F Ground Engng V18. N5, July 1985, PIZ-I5 A report on a lecture examining the development of what is now accepted piled foundation design practice from empiricism, as understanding of the fundamental principles involved improved. 862192 Stability of vertical shaft excavations Washbourne, J Ground Engng V18, NS, July 1985, P16-19 Using the Kirsch elastic theory equations and applying them to a vertical shaft, the stability of a vertical shaft excavation is assessed. 862193 Effect of stone column yield on settlement of rigid foundations in stabilized clay Balaam. N P; Booker, J R Int J Num Anal Meth Geomech V9, N4, July-Aug 1985, P331-351 The settlement of a rigid foundation supported by a layer of clay stabilized with stone columns is considered. An analytic solution for the settlement is used to develop an interaction analysis which takes into account the yielding within the stone columns. It is based on a number of plausible assumptions regarding the behaviour of the clay and columns. To check assumptions, elasto-plastic finite element analyses were performed. Very good agreement was found between the two methods. The analysis is used to obtain a series of parametric solutions which provide a basis for estimating the reduction in settlement of the foundation due to the stabilization of the clay. 862194 Torsional response of piles in nonhomogeneous soil. Technical note Chow, Y K J Geotech Engng Div ASCE Vlll, N7, July 1985, P942-947 A discrete element approach is presented for the analysis of torsional response of piles in nonhomogeneous soil. Discrete element matrices are presented for the pile and the soil that 0

can be readily implemented into a computer program. The accuracy of the discrete element method is examined by comparison with analytical solutions and with the finite element method, The application of the method in practice is shown by the back analyses of two reported full scale torsional field load tests. 8621% Foundation engineering for deep water platforms (In Norwegian) Hoeg, K Norw Geotech inst Pub1 N157, 1985, PS-6 Deep water platforms encounter difficult soil conditions of soft normally consolidated clays and loose silts. As water depth increases, the natural period of the structure increases. Future (deeper) fixed structures will require dynamic analyses and estimations of foundation stiffness, stiffness degradation and damping to a higher accuracy than is presently possible. 862196 Load teat of a shallow foundation on a scree-covered slope (In French) Aste, J P; Guerpillon, Y Rev Fr Geotech N32, 1985, P29-45 The A40 motorway near Nantua. France, crosses a scree covered slope on a viaduct with large diameter piles driven into the underlying sandstone. An alternative footing design, an inclined shallow foundation with anchors, was proposed. This design was field tested using a quarter scale model, loaded by vertical anchors. The load test was monitored to gather accurate information of displacements at the ground surface and under the footing. Results indicate this design may be competitive with deep piles for similar cases. 862197 Example of rupture of prestressed ground anchored foundations (in French) Sanglerat, T R A; Sanglerat, G Rev Fr Geotech N32, 1985, P71-80 A case history describes the failure of prestressed anchors used to support a structure with a 200ft span cable supported fabric roof, which partially collapsed on failure. The foundation design, site investigation and cause of failure - insufficient grouting and subsequent anchor corrosion - and remedial measures are described. 862198 Tubular cavities in the residual lateritic soil foundations of the Tucurui, Balbina and Samuel hydroelectric dams in the Brazilian Amazon region Cadman, J D; Buosi, M A Proc 1st International Conference on Geomechanics in Tropical L.ateritic and Saprolitic Soils, Brasilia, II-14 February 1985 V2, Plll-112. Publ Sao Paulo: Bra:ilian Society for Soil Mechanics, 1985

Tubular cavities were found in the residual soil foundations for three Brazilian dams. The origin is possibly non-recent termitic activity or tree roots. or earthworm activity. To prevent the possibility of soil erosion or piping or the percolation loss of large quantities of water, cutoff trenches were constructed and the cavities filled with cement grout. The amount of remedial work undertaken depended on cost considerations. It is likely that similar cavities exist in other areas of similar soil and climatic conditions.

1986 Pergamon Press Ltd. Reproduction

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