Seismic Response of WasteTyre Reinforced Embankment Slopes Based on Shaking Table Test

Abstract

The seismic behavior of unreinforced and waste tyre-reinforced embankment slopes was investigated through 1-g shaking table tests. This study examined the effects of various factors on the stability of embankment slopes. The factors include the vertical waste tyre reinforcement spacing, seismic waves, peak ground accelerations. The influence of reinforcement methods on acceleration amplification factor, crest settlement and internal failure mechanism are also investigated. The results suggest that the beneficial effects of tyre-reinforcement are more pronounced in embankment slopes with smaller vertical reinforcement spacing and larger peak ground acceleration. Tyre-reinforced slopes can decrease the crest acceleration amplification factor by more than 32% compared to unreinforced slopes when subjected to a 0.4g Wenchuan earthquake input motion. In addition, with Wenchuan earthquake input motion, the average acceleration amplification factor reduction of slopes reinforced by triaxial geogrids is roughly 1.4 to 2 times greater than that of slopes reinforced by a composite of waste tyres and triaxial geogrids, or by a composite of waste tyres and tyre shreds. Along the surface of the slopes, from about one-third of the slope height, the acceleration amplification factor of all embankment slopes increases gradually with elevation, and the maximum accelerations were observed on the top of the slope. The unreinforced slope displaced more significantly compared to the reinforced slope when subjected to the same peak ground acceleration. The relative displacement of an unreinforced slope is almost 1.25 times greater than that of a tyre-reinforced slope, for a 0.1g Wenchuan earthquake input motion. The corresponding multiples are 1.4 and 1.58 for 0.2g and 0.4g accelerations, respectively. The captured failure pattern on embankment slopes further indicates that a tyre-reinforced slope has smaller cracks with shallow depth and more uniform deformation than those in an unreinforced slope, when subjected to a 0.4g Wenchuan earthquake input motion. Therefore, the tyre-reinforced soil, which has the potential to be more widely used and the benefit of reducing waste disposal costs, could improve some engineering properties of slopes much like the triaxial geogrids.