Abstract: At present, the theoretical research on the uplift capacity method of horizontal anchor plate is limited to sandy soil and saturated soft clay foundations, with challenges in artificially distinguishing shallow and deep buried types. There is no research result on the uplift capacity calculation method applicable to both different buried depths and cohesive soil foundation. This paper employs numerical simulations and theoretical analyses to address issues related to sliding surface characterization, mechanical model, and bearing capacity calculation method for horizontal strip anchor plates in cohesive soil foundations. The main conclusions are summarized as follows: (1) With a constant burial depth ratio, the sliding surface expands outward as soil cohesion increases. Conversely, with a constant cohesion, the sliding surface contracts as the burial depth ratio increases. For each burial depth ratio (or cohesion) value, there is a corresponding cohesion (or burial depth ratio) value where the sliding surface changes morphology. (2) The sliding surface evolution is described by an elliptic arc, with its axial ratio varying with the burial depth ratio and soil mechanical parameters. The ratio k decreases with the increase of buried depth ratio and increases with the increase of cohesion, while the internal friction angle minimally affects it, only determining the initial angle of the sliding surface. According to this law, a formula for calculating the ratio axial k and the initial angle is proposed. (3) Combined with the morphological tendency of the sliding surface, a mechanical model for the ultimate uplift capacity of horizontal anchor plate in cohesive soil foundation was developed. The model considers the relationship between buried depth, ellipse vertex (or the highest point of ellipse position) and anchor plate position under five working conditions. The ultimate uplift capacity calculation method was derived using ultimate equilibrium analysis. This method does not need to introduce the critical depth ratio to distinguish the buried type, and can consider the changes of internal friction angle and cohesion of soil. (4) Compared to four other methods in the calculation of three test cases, the uplift capacity calculation method proposed in this paper achieves the best calculation effect and demonstrates good applicability.

Key words: strip anchor plate, cohesive soil, slip surface, mechanical model, uplift capacity