Abstract: This paper presents the evaluation of the influence of underlying water bearing marl on the vertical and horizontal movement of the upper unstable soil slope. Six factors that might potentially affecting the slope displacement, including slope height, slope angle, cohesion and internal friction angle of soil, Poisson’s ratio as well as elastic modulus of soil, were evaluated. Applying the strength reduction method in the finite element analysis and a single factor sensitivity evaluation method, the instability was therefore determined. The influence parameters analysis of the slope soil displacement and comparing the analysis results show that the order of sensitivity of the displacement influence parameters of the unstable slope is ranked in descending order: slope angle, slope height, elastic modulus, Poisson’s ratio, internal friction angle and cohesion. For slopes that are in an unstable state, the changes that affect the displacement are the slope angle and slope height. Under the same conditions, the displacement in the horizontal direction is always greater than the displacement in the vertical direction.

Key words: unstable slope, marl, displacement parameters, sensitivity analysis