A Novel Construction Method for Buried Pipes using Geosynthetics

This paper describes preliminary results of a novel construction method developed to reduce the vertical stresses on buried pipes. The method, named Geovala (vala means trench in Portuguese), involves the use of geosynthetic reinforcement layers placed within the soil mass, above the crown of the buried pipe. The main objective is to redistribute the vertical stresses acting on top of the pipe to the lateral surrounding soil. The construction methodology involves not only trench installation but also of construction of protecting structures. An experimental testing program was conducted to evaluate this system. The results obtained from tests conducted in both small- and large-scale facilities show that vertical stresses acting on top of the pipe can be significantly reduced by using geosynthetic reinforcement. The variables governing the design include the layout of the geosynthetics (length and position of the reinforcement in relation to the top of the structure), the soil type, the soil density, and the stiffness of the geosynthetic inclusion. It is expected that implementation of this construction technique will allow the use of more flexible pipes as well as their placement at more shallow depths. This can lead to significant cost savings in projects involving pipes in civil and environmental applications.