Vertical uplift resistance of plate anchors with the fluctuations of groundwater table

Abstract

Closed-form analytical expressions have been developed for computing the vertical uplift resistance of strip, circular, square and rectangular plate anchors buried in sand for different position of the groundwater table. The analysis was performed by using the upper bound theorem of limit analysis based on a rigid block collapse mechanism with planar discontinuities. The results are provided in terms of dimensionless uplift factors Fγs and Fγ for the water table above and below the level of anchor plate, respectively, due to the unit weight of soil mass. For a given soil and anchor geometric properties, the minimum magnitude of Fγs is always found to occur when the water table lies at the ground surface, and maximum magnitude of Fγs becomes equal to Fγ. The ratio of minimum value of Fγs and the value of Fγ has been found to be equal to the ratio of submerged unit weight of soil to the unit weight of soil above the water table. The solutions of the present theory compare quite well with the results reported in the literature.