6.5         Summary and Conclusions

From the work shown in this chapter one can find that foam can reduce pressure on adjacent structure in one of three ways, energy absorption, activating an active state of stresses in the adjacent cohesionless soil and by arranging the foam blocks in such a way that utilizes its free standing property. Out of these three methods the following conclusions can be obtained:

·         Geofoam can experience large strains while limiting the stresses induced in it to a specific value resulting in a large area below the stress strain curve.

·         The area under the stress strain curve between the loading and the unloading portions can be utilized in reducing work transferred to adjacent structures.

·         The area under the stress strain curves is large for the first loading cycle and for the following cycles as long as strains are less than approximately 1%. It decreases as the strains increases and remains constant when reaching 10% strain loading patterns.

·         A compressible inclusion will reduce lateral stresses induced by sand backfill by activating the active state of stresses.

·         Leaving a gap between the foam blocks and the retaining structure will eliminate any lateral pressure on the structure.

·         The light weight property of the foam, by it self, will not decrease the dynamic stresses on the indeterminate structures. Utilizing the damping property of the foam will decrease the dynamic stresses in the structure.