843199 Frost sensitivity of core materials: case histories Solymar, Z V; Nunn, J O H Can Geotech J V20, N3, Aug 1983, P373-384

The Waterloo Lake Dam, Canada, a simple zoned earth-rockfill structure with a wide central impervious core of silt, has gradually deteriorated due to frost penetration of the core material. Longitudinal cracking and silt outflows have occurred along the crest. Based on this experience the White Lake Dam, a simple zoned earth-rockfill structure, incorporates an im- pervious membrane in the gravel shell and a gravel cover over the core to reduce frost penetration and heave. In situ and laboratory freeze-thaw and permeability tests were carried out during the construction of the Chariot River Dam to assess possible frost damage, and the use of silty sands with added ben- tonite has ensured minimum frost susceptibility.

8432OO Design and construction of Revelstoke earthfill dam Taylor, H; Lou, J K Can Geotech J V20, N3, Aug 1983, P416-427

The Revelstoke Project includes a 175m high concrete gravity dam, a power plant and a 125m high earthfill dam on the Columbia River, British Columbia, Canada. The earthfill dam consists of a central till core with upstream and downstream granular shells built on metasediments overlain by glacial and interglacial deposits. A core trench was excavated to found the core on rock and electroosmosis was used to stabilize the core trench in areas of soft wet silt. The overburden material used was sand and gravel. Density and standard penetration tests were carried out to assess the liquefaction potential under seis- mic loading of the silt/clay and fine sands under the shell of the earthfiU dam.

843201 Bearing capacity of dykes and fills founded on soft soils of fimited thickness Silvestri, V Can Geotech J V20, N3, Aug 1983, P428-436

Proposes a method by which the critical condition at which failure is impending is analysed in terms of the bearing capacity of the soft clay foundation, instead of the conventional slope stability approach of the fill-clay interaction. 10 case histories, covering a wide range of soft clays, are investigated and the results compared with those obtained by the conventional method. The advantage of the plasticity method is that the fac- tor of safety is given explicitly by a very simple equation.

843202 Plastic deformation of an embankment on clay Wu, T H; Hsu, J R; Ali, E M Can Geotech J V20, N3, Aug 1983, P437-452

A simplified elastic, plastic, work-hardening stress-strain model was used to analyse the results of triaxial tests on kaolinite, grundite and a lacustrine clay. The stress-strain model was used to compute the displacements of an embankment on clay and a sensitivity analysis was performed to evaluate the influence of the various model parameters on the computed displacements. It was found that the preconsofidation pressure, which defined the yield point and the initial horizontal stress, had the largest influence.

843203 Geostatisticai analysis of a dam core (In French) Soulie, M; Favre, M; Konrad, J M Can Geotech J V20, N3, Aug 1983, P453-467

The structure and randomness inherent in a dam core are taken into consideration in the geostatistical approach applied to this study of the LG-3 dam, James Bay, Ontario, Canada, built with

102A

glacial till. From the variograms obtained, the problems of estimating the mean compaction degree of a given volume are studied.

843204 Magat Dams: design of internal filters and drains Hillis, S F; Truscott, E G Can Geotech J V20, N3, Aug 1983, P491-501

Four rock fill dams with cores of highly weathered residual sand and gravel were built as part of the Magat River Multi-Purpose Project, Luzon Island, the Philippines. As the project area is seismically active the adequacy of the proposed filters and drains was checked by a series of large scale tests involving a 580ram diameter permeameter and a large flume, carried out on intact and cracked core material. It was concluded that: (1) filter gradations chosen were satisfactory, (2) two filter zones were re- quired between the dam core and the chimney drain, (3) conven- tional filter criteria were over conservative in this case and (4) conventional criteria do not apply to the case of a cracked core.

843205 Earth reinforced dams: first in US Civ Engng, N Y V53, NIO, Oct 1983, P60-63

Earth reinforcement, using metal strips which reinforce the earth fill in the directions in which it is subject to the greatest stresses, has been used for dam restoration and construction at four sites in the US. The 110 year old stone masonry dam at Jamesville, New York and the 62 year old Lake Sherburne Dam, Northern Montana were restored using Reinforced Earth. The process was also used in the construction of the 74ft high Taylor Draw Dam, Colorado, and the Woodhollow Dam, Texas.

843206 Geotechnical aspects of the Kieider Dam Millmore, J P; McNicol, R lnst Civ Engr Proc V74, Nov 1983, P805-836

The 52m high Kielder Dam, Northumberland, UK, an earth fil- led embankment dam, is founded on complex geology of the Lower Carboniferous era. Underseepage was controlled by ex- tending the clay dam core upstream as a clay blanket and in- stalling relief wells. The rapid construction of the dam necessitated extensive site investigation: piezometers were in- stalled to monitor pore-water pressure development and dis- sipation and magnetic settlement plates around the inclinometers to measure vertical movement in the core and shoulders. As a result of large vertical deformation two stability berms were constructed.

843207 Reinforced embankments: analysis and design Rowe, R K J Geotech Engng Div ASCE VIIO, NGT2, Feb 1984, P231- 246

A numerical technique for the analysis of geotextile reinforced embankments is outlined. The technique permits consideration of soil-reinforcement interaction, slip at the soil-fabric inter- face, plastic failure of the soil and large deformations. The behaviour of an instrumented embankment constructed using geotextiles on a soft peat deposit is shown to follow the pre- dicted behaviour. It is then shown how the results of a finite ele- ment analysis may be used as the basis of a practical design procedure involving the use of simple design charts.