Pseudo-Static Uplift Capacity of Horizontal Strip Anchors

Damages of ground anchors during any devastating earthquake are well known. Researches on the topic of ground anchors under both static and seismic loadings are important for geotechnical engineers. Geotechnical applications of horizontal strip anchors are well known for structures subjected to uplift loading like towers, pipelines, high rise building foundations etc. In this paper, an analytical method to compute the vertical uplift capacity of horizontal strip anchors under both static and seismic conditions are described. The pseudo-static approach is used with the limit equilibrium method to obtain the net seismic vertical uplift capacity factor for unit weight component (F_γd) for horizontal strip anchor by considering the distribution of soil reaction on the simplest planer failure surface through the use of Kötter's equation. Results for F_γd are computed for various combinations of input parameters like soil friction angle, embedment ratio, both horizontal and vertical pseudo-static seismic acceleration coefficients. It is observed that with increase in both the seismic acceleration coefficients, the uplift capacity factor decreases significantly. However, the uplift capacity of horizontal strip anchors increases with increase in embedment ratio, as expected, in seismic conditions also. Present results are compared and found in good agreement with the results available in literature.