| Abstract: |
whereas, soft clays possess undrained shear strength ranging between 12.5 kPaand 25 kPa. In addition to the low shear strength of soft clays, they experiencehigh compressibility upon loading. This is why soft clays are considered asproblematic for foundation purposes. Many projects have to be constructed insoft clay zones, where whether deep foundation piles or elaborate soil treatmentschemes is utilized. In all these projects there exist many light-weight structuressuch as fence walls, guard towers or rooms, light poles, utility inspectionchambers, pipe racks, roads, etc. The design engineer is faced with challenges inselecting safe and economic solutions for the foundations of these lightstructures by avoiding the use of deep foundations or other costly soilimprovement 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 geotechnicalapplications as a light weight fill, as a compressible inclusion and also as aseismic and lateral buffer behind earth retaining structures. The increased useand applications of EPS as a Geofoam material has evolved due to its very lowdensity and high strength-to-density ratio. Typical recent applications of EPSGeofoam include filling around and above underground structures such asbasements, culverts and pipes, embankment roads on soft ground, replacementof very soft soil under roads and pipes, widening existing fills and roads and infilling 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 acompressive strength ranging between 70 kPa and 140 kPa and an elasticmodulus ranging between 5 MPa and 12 MPa, Table (1) illustrates the relationbetween EPS density and the compressive strength at a strain of 10%, according.
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