الفهرس 
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Abstract
whereas, soft clays possess undrained shear strength ranging between 12.5 kPa
and 25 kPa. In addition to the low shear strength of soft clays, they experience
high compressibility upon loading. This is why soft clays are considered as
problematic for foundation purposes. Many projects have to be constructed in
soft clay zones, where whether deep foundation piles or elaborate soil treatment
schemes is utilized. In all these projects there exist many light-weight structures
such as fence walls, guard towers or rooms, light poles, utility inspection
chambers, pipe racks, roads, etc. The design engineer is faced with challenges in
selecting safe and economic solutions for the foundations of these light
structures by avoiding the use of deep foundations or other costly soil
improvement schemes.
Geofoam is an industrial material, characterized by a very low unit weight
(average of20 kg/rrr’) compared to that of the soil. According to Horvath (1996,
1997) EPS Geofoam blocks are used in a wide range of geotechnical
applications as a light weight fill, as a compressible inclusion and also as a
seismic and lateral buffer behind earth retaining structures. The increased use
and applications of EPS as a Geofoam material has evolved due to its very low
density and high strength-to-density ratio. Typical recent applications of EPS
Geofoam include filling around and above underground structures such as
basements, culverts and pipes, embankment roads on soft ground, replacement
of very soft soil under roads and pipes, widening existing fills and roads and in
filling and support of bridge abutments and slope stabilization (Horvath 2005).
Having a density ranging from 1.0% to 2.5% of that of soil, EPS possesses a
compressive strength ranging between 70 kPa and 140 kPa and an elastic
modulus ranging between 5 MPa and 12 MPa, Table (1) illustrates the relation
between EPS density and the compressive strength at a strain of 10%, according.