Protection of buried pipe using soil bag

In recent years, geosynthetics have been increasingly used to reinforce soil mass on pipes under static and repetitive loads. Soilbags are also effective for managing floods and various geotechnical applications, such as roadbeds, slope stability, and retaining walls. In this paper, the investigation of the buried pipe’s behavior in the unreinforced trench and reinforced trench with soil bag is considered. Therefore, a series of tests were conducted on the unreinforced and reinforced trench (reinforced by one soil bag, two soil bags in columnar arrangement with and without spacing, and three soil bags in two layers of stepped arrangement) containing a pipe with a diameter of 160 mm under static load. The results of the tests show the effect of the soil bag layer on reducing the bed settlement by enclosing the soil inside and preventing the lateral movement of the soil mass above the pipe. Also, the bag, by distributing the stress on a wider surface and significantly reducing it in depth, reduces the transfer stress to the pipe crown and as a result, reduces the deformation of the pipe. Increasing the buried depth of the soil bag results in a reduction in deformation and pressure on the pipe crown and an increase in soil surface settlement. The columnar arrangement of two layers of soil bags with spacing provides better performance in improving pipe behavior compared to those without spacing. Moreover, the use of two layers of soil bag with a stepped arrangement leads to a reduction in surface settlement, pressure on the pipe, and pipe deformation compared to two layers of soil bag with a column arrangement. However, considering the lack of significant difference between the behavior of the stepped and column arrangements (with or without spacing), the use of a column system is recommended, as it saves 33% of the soil bag.