AN INNOVATIVE GROUND ANCHOR FOR DEEP EXCAVATIONS IN VIETNAM

Abstract

Large excavation-induced deformation of the anchored wall due to the limitation of anchor rod capacity in thick soft soil strata remains a problem in a deep excavation. In this paper, the performance of an innovative anchor type, so-called Hotdog anchor, invented by Korean engineers is investigated using the numerical and field test methods for excavation in Southern Vietnam. For comparison, both hotdog and pack anchor types are introduced in the case study. Proof tests of anchors were also conducted to provide data for the simulation. Four layers of hotdog anchors with 12m-bond length and 40 cm-diameter are adopted to compare with 4 layers of 18m-bond length and 20cm-diameter pack anchors in a soft to medium clay layers (NSPT = 1 ~ 13). In numerical analysis, the soil behavior was simulated using the Mohr-Coulomb model.  The plate and node-to-node anchor elements were adopted to model the diaphragm wall and the anchors, respectively. Results show that the hotdog anchors could provide the larger bearing capacity and so that decrease the required bond length as compared with the pack ones. Based on that a guideline for the adoption of hotdog anchor to deep excavations in thick soft soil deposit in Southern Vietnam was proposed.