The sedimentology of the lagoons and island of Abu Dhabi was studied in detail by Douglas Shearman and his colleagues during the 1960s. Since that time, the island has undergone extensive development and a considerable database on the ground conditions in the area exists from site investigations. Despite this, there are few published data on the engineering characteristics of these sediments; this paper addresses this shortfall. A brief description of the environments of deposition and the sediments of the foreshore, tidal delta and the lagoons of the Abu Dhabi coast is presented, and the effects of both the origin and the diagenesis of these sediments on their engineering properties is examined. Results from a selection of site investigations are summarised to present characteristic values for the various sediments. Physical property data reported include: lithology and grain-size profiles; moisture contents; bulk and dry density; porosity; estimated degrees of saturation; unconfined compressive strength; standard penetration test (SPT) values; soil and groundwater chemistry (chloride and sulphate contents); and plasticity charts (plasticity index versus liquid limit). The ground conditions are also reviewed to identify significant issues that need to be addressed for the design and construction of engineering projects in Abu Dhabi.The data show that there is a contrast between the strength and compressibility and salt content of the granular, often cemented deposits of the higher energy beach and nearshore environments, and the soft or very loose silts and fine sands of the lagoons and sabkha. A decrease in the strength of the underlying calcarenites with depth to about 10 m below ground level is thought to reflect the effect of diagenetic alteration of the carbonates from aragonite to high-magnesium calcite.

This paper describes the use of an 11-year time series of condition measurements obtained from a random sample of road sections on all classes of one local authority's roads to evaluate the changing condition of the sections. The condition has been defined in terms of macro-texture, rut depth and longitudinal profile. Deterioration models have been developed using the repeat measurements after allowing for routine measurements. The results have also allowed initial estimates of required maintenance cycles to be established for macro-texture and for the development of rut depths. Longitudinal roughness values collected as part of the study suggest that the roads included in the study have overall structural capacity and that only the surface layers deteriorate.

Sedimentary environments within a lagoonal r6gime and the occurrence of sediment types, with specific reference to the Lagos area, are described. The engineering properties of the sediments may be related to their environment of deposition and the effect of their variation on the development of the area is considered.

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