Efficiency of partially penetrating vertical drains

863O86 Et~iency of partially penetrating vertical drains Runesson, K; Hansbo, S: Wiberg. N E Geotechnique V35. N4. Dec 1985. P511-516 The problem of consolidation of a clay layer in which vertical partially penetrating drains have been installed is dealt with. The influence of well resistance is considered in the anal}sis, which is performed by means of the finite element method. The drainage pattern for each drain is assumed to be axisymmetric. Diagrams of the average degree of consolidation versus time for some selected non-dimensional parameters are presented. These diagrams indicate, for partially penetrating drains, that the delay in the consolidation process within the zone penetrated by drains (due to higher excess pore water pressure in the underlying undrained zone)is noticeable only to a very limited height above the drain tips. In the case studies presented, the delay is negligible to a depth corresponding to at least 80% of the partially penetrating drain length. Auth.

863087 Settlement characteristics of lateritic soils near Worsley Smith, D M A Proc 4th Australia-New Zealand Conference on Geomechamics, Perth, Western Australia, 14-18 May 1984 V2. P477-481. Publ Barton." [nst of Engineers, 1984 Summary of salient results, discussing the settlement characteristics of lateritic soils by presenting a case study of the settlement monitoring of an earthen embankment. Suitable investigation methodology for foundation design in the lateritic soils of the Worsley environment, Western Australia, is recommended.

863088 Consolidation around a heat source Booker, J R; Savvidou, C Proc 4th Australia-New Zealand Conference on Geomechanics, Perth, Western Australia, 14-18 May 1984 V2, P551-554. Publ Barton: [nst of Engineers. 1984 The distribution of temperature and pore pressure around spherical and cylindrical sources is examined. The consolidation of the surrounding soil significantly reduces the increase in pore pressure due to temperature increases, and this reduces the risk of cracking.

863089 Compressibilities of lateritised granitic soils near Worsley Smith, D M A Proc 4rh Australia-New Zealand Conference on Geomechanics, Perth, Western Australia, 14-18 May 1984 V2, P471-476. Publ Barton: [nst of Engineers, 1984 The compressibility properties of the residual granitic clays and silts over the site for the Worsley Alumina Refinery are discussed, as are the most suitable methods of measuring these properties. Suitable tests include large scale embankment load testing with settlement monitoring, and camkometer, screw plate and conventional plate load testing.

863O90 Optimisation of the manufacture of bricks from expansive soils (In French) Olivier. M Proc Ist International Conference on Geomechanics in Tropical Lateritic and Saprolitic Soils, Brasilia, I1-14 February 1985 V2. P413-423. Publ Sao Pauh~: Bra:ilian Societ.v for Soil 3/echanics. 1985 It is demonstrated that it is possible to make bricks from expansive soils, compressed in an oedometric quasi-static manner (between 20-100 bar). which have good mechanical properties whate~er the starting material. To achieve this it is necessary to relate the compression force to the water content of the mixture and possibl.,, to use a binder. This relationship may be determined rapidly by using the Proctor Static Method. An example of the use and interpretation of this method is presented. 863O91 Experimental studies of the behaviour of tropical andosolitie materials under different types of stress (In French) Rosello, V; Tessier. D; Chevin, P Proc 1st International Conference on Geomechanies in

Tropical Lateritic and Saprolitic Soils, Brasilia, 1!-14 February 1985 V2. P423-434. Publ Sao Paulo: Bra=ilian Societ.v for Soil Mechanics. 1985 Despite low apparent densities, andosols from Reunion Island are not susceptible to settlement and are stable in their natural conditions. These materials have complex microstructures with four successive levels of organisation, with aggregates from less than 1 micron through to a continuous microstructure. Water content and void index have been studied at pressures up to 1000 bar. The microstructure is stable at pressures to 10 bar, but at higher pressures, loss of v,ater affects the mineral particles themselves and destabilises the microstructure. The properties are totally changed. Mechanical treatment similar to the compaction which would occur on a building site does not affect the structure on a micron scale at pressures below 10 bar. This microstructural stability gives these andosols a low compactability.

863092 Simple methods for evaluating expansiveness of unsaturated subtropical soils El-Sohby, M; Mazen, O Proc 1st International Conference on Geomechanics in Tropical Lateritic and Saprolltic Soils, Brasilia, !1-14 February 1985 V2. P443-449. Publ Sao Paulo: Bra=ilian Socieo" for Soil Mechanics. 1985 In order to examine the relationship between swelling behaviour and other soil parameters, samples from Cairo, were submitted to laboratory testing. Swelling pressure, Atterberg limits, grain size distribution, densities and natural moisture content were measured. Mineralogical analysis by x-ray diffraction was undertaken, and relationships between measured properties examined. Variations in behaviour indicated swelling characteristics could be correlated with soil properties such as Atterberg limits and activity.

863093 Foundation behaviour in calcareous sand Poulos, H G; Hull, T S; Chua, E W Proc 9th Australasian Conference on the l~lechattics of Structures and .~laterials, Sydmey, 29-31 Aug 1984 P28-32. Publ Sydney: School of Ciril and Mining Engng. 1984 The basic strength and compressibility properties of an uncemented calcareous sand from Bass Strait, Australia, and a silica sand from the Sydney area were measured in the

~ 1986 Pergamon Press Ltd. Reproduction not permitted