Improvement of clay subgrade soil using geogrid and geocell reinforcement: An experimental investigation

The subgrade soil and its properties are crucial in designing pavement structures because they provide adequate support for the pavement. The subgrade must be capable of supporting the loads applied by the pavement structure without excessive deformation under adverse climatic and traffic conditions to extend the pavement’s life. Not all soils possess the required characteristics, but some are suitable good-quality materials for pavement construction. Therefore, whenever soils cannot be replaced, many methods for modifying their performance as subgrade materials should be applied. Among those methods, reinforcement of subgrade soils has become a very common practice in recent years. There are many methods currently being used to reinforce soils, including the use of geogrids or geocells. In this research project, geogrids and geocells were used as soil reinforcement on three different types of geogrids and geocells to enhance the performance of clay subgrades. Samples of clay from Baghdad, Iraq, were measured for swelling potential and CBR with and without geogrids and geocells at various depths in a mold. Swelling and CBR of moist soils improved when geogrids or geocells were used to reinforce the soil, and both resulted in a maximum CBR when geogrids and geocells were placed at 0.3 of the height of the molded clay sample.