Evaluation of the use of residual soils of the Batolito of Antioqueño stabilized with quicklime for the construction of embankments and mechanically stabilized retaining structures

Abstract

In general, road construction requires the exploitation of large quantities of granular materials, and this generates significant economic and environmental impacts. The use of excavated materials for the construction of fills, embankments and reinforced earth retaining structures is an ideal solution to reduce the exploitation of raw materials. However, the use of excavated materials can be limited when these materials are fine-grained or have low mechanical specifications. In this sense, soils stabilized with quicklime have become a viable alternative for road construction, reducing the use of quarried materials. Although there are standards and techniques for the use of quicklime improved soils for pavements, today the evaluation process of these materials for embankment and fill construction is not well established. This paper presents the results of an investigation to determine the impact of quicklime soil stabilization on the design of embankments and retaining structures reinforced with geosynthetics. First, a road embankment is presented for which a sensitivity analysis was carried out in terms of geometry and volume of material required. Secondly, a mechanically stabilized wall with geosynthetics is presented in which a sensitivity analysis is performed in terms of the amount of geotextile reinforcement required. In both cases, the models were analyzed using the shear strength parameters of a residual soil of the Antioquian batholith in its natural state and stabilized with quicklime obtained in laboratory tests. A quicklime content of 2% and design processes according to Federal Highway Administration (FHWA) manuals were used. The results show that in the embankment a reduction in the volume of material is obtained when using stabilized soil of around 15%, since greater slopes and heights can be used with respect to the geometry of the soil in its natural state. In the case of the stabilized wall, a reduction of approximately 50% in the amount of geosynthetics required was observed, since with the case of stabilized soil it is possible to achieve layer reinforcements of greater thickness and lower strength than those obtained with the soil in its natural state. Both cases show that the implementation of soils stabilized with quicklime can be beneficial in terms of costs since a reduction in resources and materials can be achieved.