Composite linear is widely used in modern sanitary landfills.Composite failure is one of the possible failure modes of landfills

in which the failure surface is through the waste mass and along the bottom liner systems.The corresponding calculation method must be modified for combined failure mode of landfill slopes.In this paper

the potential slide wedge was divided into two discrete parts

i.e.an active rotation sliding block and a passive translational sliding block.The expression of the critical load is derived for the passive sliding block on the basis of the limit equilibrium theory.Based on the limit analysis upper bound theorem

the rotation sliding failure mechanism of the active block is analyzed to propose the calculation formula of the residual sliding force.Considering the interaction between passive and active blocks

the stability analysis method for combined failure mode of landfill slope is established considering the effect of leachate level.The results show that the stability of landfills could be improved significantly with a larger internal friction angle of bottom liners compared with cohesion.If the leachate level at back slope of landfill increases

the possibility of large-scale failure in landfill is greater.With a higher value of leachate level at front slope of landfill

the shallow waste mass near the front slope may fail easily.Therefore

it is necessary to pay attention to the rise of leachate level to ensure the safety of landfill

and it is recommended to use geotextile materials with a higher internal friction angle in practical engineering.