Uplift load tests on model spread foundations in cement-stabilized aeolian sand

Aeolian sands are inherently very low in strength and very high in compressibility because they are loose, cohesionless and easily movable. The cement-stabilization of aeolian sand may be an alternative method to improve the mechanical characteristics of aeolian sand in the desert areas. In this study, the aeolian sand samples collected from the Hobq Desert are remoulded with a moisture content of 3%, and a relatively small amount of cement of 6% by weight of dry aeolian sand is added to the aeolian sand backfill. A total of 9 uplift load tests are carried out to investigate the uplift performance of model spread foundations embedded in cement-stabilized aeolian sand. The experimental results demonstrate that the cement-stabilized aeolian sand has a typical brittle nature, and two-phase pre-peak and post-peak behaviours of load-displacement responses are observed in all the tests on the model spread foundations embedded in the cement-stabilized aeolian sand. Under uplift loading, when the normalized embedment ratio of depth to basement width for spread foundations is less than 3.5, the displacement corresponding to the ultimate uplift resistance ranges from 0.04%~1.05% of the basement width, with an average of 0.54%. Based on the uplift capacity of shallow spread corresponding to the peak failure resistances, the magnitudes of the slope angle α of the dead weight method are calculated for each of the spread foundations. Compared to the natural aeolian sand, the significant increases in uplift resistance and slope angle α of the dead weight method can be obtained for model spread foundations subjected to uplift in the cement-stabilized aeolian sand, irrespective of embedment ratios of H/D. © 2017, Editorial Office of Chinese Journal of Geotechnical Engineering. All right reserved.