Geogrids, an option for the reinforcement of soft soils under reinforced concrete structures

Abstract

Construction professionals are at the forefront in reinforcing the soil with the use and application of methods and materials that help increase its bearing capacity, since one of the main causes of building collapse and settlement is soft soil.  For this study, a five-story reinforced concrete building was designed using structural software and a soil-structure interaction analysis was performed. Immediate and differential settlements were calculated with the application of loads from the structure. Four reinforcement analysis models were considered: 1) without improvement; 2) with soil replacement; 3) with geogrids; and 4) with geogrids and footing width reduction. The bearing capacity was estimated using data from soil studies and material parameters from quarries near the study area in Portoviejo, Ecuador. An adaptation to the formulas of Meyerhof & Hanna (1978) was applied for the soil substitution alternative, while the formulas of Huang & Meng (1997) were used and applied for the geogrids. The aim of this analysis is to obtain a high bearing capacity value of the soil that leads to savings in foundation material and at the same time to achieve low numbers of settlements that are deduced to the safety of the structure. The results of the reinforcement in relation to the natural soil revealed a considerable increase for the geogrid alternatives compared to soil substitution, and a reduction in settlements. The percentages obtained after analysis and calculations demonstrate the benefits of using geogrids under this type of structure.