The National Transport University Bulletin

Abstract

The purpose of the proposed article is to evaluate the tensile strength and long-term strength values, taking into account the creep of polymer geogrids in reinforced soil structures, their further long-term analysis at transport infrastructure facilities with limited construction conditions. The authors have performed a comparative analysis of polymeric geogrids with different types and orientations, which are widely used in reinforced soil structures, have the same tensile strength values depending on the manufacturing technology, structure and raw material. Comparative tables with all changes of a long-term strength those geogrids are given. The value of reduction and nominal long-term strength of geogrids is analyzed. Sufficient previous experience in the design of soil structures with geosynthetic reinforcement with geogrids provides an opportunity for a more detailed understanding of the mechanics, operation and calculation methods of such structures. The authors have proved that the use of the long-term strength value of the geogrid in the design, taking into account the partial safety factor for the material, allows for a more accurate calculation of structures with high responsibility class, which are designed in limited and difficult conditions. This approach reduces the overconsumption of geogrids in reinforced soil structures, and optimizes the design parameters, namely the reinforcement step and the length of the reinforcing layer, which affects the projects cost and the labor intensity of the work. The analysis made it possible to determine a factor that is of a recommendatory nature for a harmonization of the national regulatory document with the European analogue. Namely – bringing the nominal long-term strength to the design long-term value of durability by introducing a safety factor for the material, which includes consideration of materials creep and coefficients like, damage during installation, the connection method, and the external environment influence.

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