The pull-out capacity of plate anchor is significantly impacted by the embedment loss during keying, necessitating its prior estimation. The soil surrounding the anchor undergoes considerable disturbance during keying, but the soil softening induced by accumulated shear strains was neglected in almost all the existing numerical studies. In this paper, an elastic-perfectly plastic model with strain-softening was combined with the integraltype nonlocal method to overcome the mesh dependency in large deformation finite element simulations. The biaxial compression tests were simulated firstly and the keying process of strip anchors were reproduced by varying anchor width, thickness, loading eccentricity, undrained shear strength and sensitivity. It was observed that the ultimate embedment loss increased nearly linearly with soil sensitivity, a trend that was especially pronounced at lower loading eccentricity ratio. The generalized equations for evaluating the ultimate embedment loss were proposed and their reliabilities were verified by the existing centrifuge tests.