Although Vertical Soil Arching is not a "Lateral Earth Pressure" issue per se, the engineered compressibility and durability of TerraFlex™ make it an ideal material for use as the "compressible inclusion" employed in the imperfect ditch concept.

Deeply buried conduits are normally subject to high stresses and it can be very challenging to economically construct deep conduits that can sustain these loads. Furthermore, when there is a failure, it can be very expensive and time consuming to effect repairs.

TerraFlex, being a synthetic, engineered, manufactured product, is uniquely qualified for this purpose. In comparison with cardboard, tire chips, (or even ordinary Geofoam) no other material can match the predictability and durability of a design utilizing TerraFlex™ as the compressible inclusion.

For more information on TerraFlex, refer to the links on this site. There is also a paper on the theory of arching available at our technical documents page.