Development of a Methodological Approach for Mapping Granular Soils for Pavement Layers

Civil engineering works require the selection of soil-type materials and the assessment of their geomechanical characteristics. However, the lack of relevant geotechnical mapping to facilitate the prediction of granular material zones for civil engineering works in Benin means that very costly and sometimes inconclusive prospecting has to be undertaken for each project. The aim of this study is to contribute to the availability of geotechnical mapping in Benin. For this purpose, and in order to capitalize on the data, the proposed methodological approach is based on the systematic and controlled recording of data produced by laboratories during geotechnical and geological surveys for road construction projects. To this end, a web platform called ROAD MAT has been designed for data recording. This platform has been tested using data from test results from sixteen boreholes drilled in the Mono department. These results show a predominance of soil class G2 and CBR class P2. The database is steadily expanding, and its use by stakeholders will make it possible to collect and centralize vital data to define benchmarks for greater control of geotechnical risks. This work therefore constitutes a blueprint for the development of geotechnical mapping in Benin.