Seismic stability of reinforced slopes: effects of reinforcement properties and facing rigidity

摘要

A series of tilting tests on reinforced model slopes backfilled with regularly packedn1.96 mm-diameter steel rods were performed to investigate the relative importance of facingnrigidity, reinforcement length and reinforcement stiffness for the pseudo-static seismic stability ofnreinforced slopes. Aluminium full-height panel with a wide range of bending rigidities andnreinforcing materials with significantly different tensile stiffnesses and interface friction angles werenused in the tests to investigate their effect on the ultimate tilting angles (or pseudo-static-basedncritical seismic coefficient) of the reinforced model slopes. It was found that, of the factorsninvestigated, the interface friction angle of the reinforcing materials plays an essential role in thenpseudo-static seismic stability of the walls. When the interface friction angle of the reinforcementnwas too low, increasing the facing rigidity or tensile stiffness of the reinforcement resulted in annegligible effect on the ultimate tilting angle of the reinforced slopes. Increasing the ratio ofnreinforcement length to wall height (Lr/Ht) from 0.52 to 0.83 provided a substantial increase in Łf ,nregardless of the interface friction angle (u0001r) and facing thickness (tm) investigated in the study.nThis effect is a promising way of increasing the pseudo-static seismic stability of reinforced slopes.nIncreasing the tensile stiffness of the reinforcing material results in a small to moderate increase ofnŁf (or khc) associated with the formation of a monolithic reinforced zone behind the facing. Fornthe ranges of facing and reinforcement parameters investigated, facing rigidity plays a secondarynrole in the ultimate tilting angle of reinforced slopes, and is realised only when a sufficiently highninterface angle of reinforcement or a relatively short reinforcement length (Lr ¼ 0.52Ht) is used.nThe relative importance of the parameters was also examined from the viewpoint of lateral facingndeformation. The deformation-based observations supported such findings in view of the criticalntilting angles mentioned above.