Coupling of horizontal joint and topography effects on seismic response of a single face slope

Abstract

A concentration of building damage and slope failure near the slope crest has been observed during numerous earthquakes. Documented researches have shown that the combination of topography and geological structure (joint) significantly affects the seismic response of the slope. To investigate this issue, a series of numerical simulation analyses are performed for a slope containing horizontal joints by varying normalized joint stiffness (K), the ratio of normal stiffness to shear stiffness (kn/ks), joint spacing, the slope height, slope angle, and loading frequency. The acceleration amplification factor in the horizontal direction (AAF-X) in the slope distributes fluctuation characteristics when K is less than 1. The AAF-X at the slope crest increases with the increase of kn/ks. Meanwhile, the AAF-X at the slope crest increases first and then decreases with the increasing joint spacing. The AAF-X of jointed slope shows fluctuation change law along the slope surface with the increasing slope height while the AAF-X generally increases for homogeneous slope. The AAF-X at the slope crest of the jointed slope is amplified for different slope heights. A complex interaction exists between the topographic and joint effects on the seismic response of the slope and the two effects cannot be easily decoupled.

Keywords

• Topographic amplification effect
• horizontal joint
• seismic response of the slope
• coupling effect