Abstract: Currently, the understanding of the load bearing characteristic and mechanism of multi-blade screw anchor is not complete, and the calculation method of bearing capacity is also not mature. In this paper, the multi-angle inclined pullout model tests of the double-blade screw anchor were carried out using a self-made model test device, and the influence of load inclination angle and burial depth ratio on load-displacement curves and bearing factor was analyzed. By quantifying the horizontal and vertical control degree, the coupling effect of the two directions was analyzed. Based on numerical simulation, the influence of anchor plate spacing and load inclination angle on the soil pressure on the anchor plate was calibrated, and a calculation method for the influence coefficient of soil pressure on the anchor plate was proposed. An approximation calculation method for soil pressure considering the influence of displacement and the p-y curve method were introduced to construct an inclined loading mechanical model of screw anchor with double blades. Furthermore, the calculation method and corresponding steps for inclined pullout bearing capacity were proposed, and good results were achieved in the calculation of 3 test cases. The research ideas of the model and calculation method in this paper can be extended to other cases with multiple anchor blades, but the screw anchor needs to meet the prerequisite of rigid short pile.

Key words: screw anchor, inclined loading, model test, blade spacing, bearing capacity