The horizontal reinforcement is a method of ground treatment for soft soil. The calculation of the ultimate bearing capacity of the reinforced grounds is important to the design of ground foundation treatment. Firstly

combined with the engineering characteristics of reinforced grounds

a changeable failure mode varying with the reinforcement parameters and the kinematically admissible velocity field are established by its failure mechanism considering the influence of the coordinate deformation between soil and the horizontal reinforcement. Secondly

with the upper limit analysis

the ultimate bearing capacity calculation was deduced by the method of energy dissipation for the level reinforcement. Thirdly

a new approach for determining the ultimate bearing capacity of the reinforced grounds is introduced by the sequential quadratic programming optimization algorithm. Finally

the comparisons with experimental results find that this proposed method is reasonable

feasible

and superior to other existing methods

also can reflect the reinforcement design parameters effect on the failure mode and its ultimate bearing capacity.