Suscetibilidade à liquefação dinâmica de uma areia eólica pura e estabilizada com resíduo de polimento de porcelanato e cal.

Abstract

In Brazil, the existence of a considerable seismic risk in the Northeast region, combined with the presence of soil deposits with characteristics of greater susceptibility to the phenomenon, as is the case of aeolian soil deposits, leads to the need for an expansion in the approach of this topic in the country. On the other hand, there is still little research with the use of stabilizers developed from industrial waste in soil improvement processes for liquefaction mitigation. In this context, this research aims to evaluate the dynamic liquefaction potential of an aeolian sand from the city of Natal in Rio Grande do Norte, a typical soil of the region and used as foundation layer for buildings and local infrastructure. Furthermore, it aims to evaluate its stabilization by incorporating porcelain polishing waste (PPW) and hydrated lime. For this purpose, cyclic triaxial tests under undrained condition were performed on pure sand samples compacted at different relative densities (25%, 50%, and 75%) and subjected to different confining stresses (50 kPa, 100 kPa, and 200 kPa) and cyclic loading intensity. The influence of stabilization was evaluated by means of unconfined compressive strength and split tensile strength tests, as well as monotonic triaxial tests in the undrained condition. The liquefaction potential of the stabilized loose sand was evaluated in cyclic triaxial tests on mixtures with 3% lime and different PPW contents (5%, 7.5% and 10%). The pure sand showed high potential for flow liquefaction with degradation of its dynamic parameters in each cycle. The resistance to the phenomenon decreased with increasing cyclic loading intensity and confining stress as well as reduction in relative density. As for stabilization, the PPW and lime content, as well as the relative density, have a positive influence on the compressive and tensile strength of the samples. The performance of the specimens in monotonic triaxial tests was also optimized with increased peak strength and reduced contractive tendency and static liquefaction potential of the sand. Stabilization increased the strength of the loose sand and reduced the rate of degradation of dynamic parameters. The performance increased with the increase in the PPW content, the highest resistance was obtained for the mixtures with 10% of residue. Thus, the high liquefaction potential of pure sand was confirmed, as well as the possibility of mitigating this potential by using a stabilizer with porcelain polishing waste and hydrated lime.