Application of fly ash for construction of an offshore island in Israel

The application of Coal Fly Ash (CFA) for the construction of an offshore island in the coastal region of Tel Aviv is considered. Three design options for the construction of a 1 km2 square island 800 m off the shore line are outlined. The demand for fill material is shown to exceed by far the expected rate of ash supply from local power stations. Preliminary design and cost estimates indicate that the caisson retained construction method with compartmentization is promising both on technological and economic grounds. The price of construction of the island can be less than half and possibly as low as one third of the expected sales value of the reclaimed land. Construction of the 1 km2 caisson retained island with compartmentization is estimated at $509 million or $640,000 per dunam with an estimated sales value of at least $1.5 million per dunam and probably higher. Due to its limited availability the ash will be used to form a compacted fill layer mostly above sea level. This provides an additional environmental safeguard. Finally other uses of the ash in the form of aggregates and as a replacement for cement are described. 2 refs., 5 figs., 3 tabs