Centrifuge test study on the influence mechanism of anchor cable installation on the seismic response of pile‒anchor structures

Abstract

Anchored stabilizing piles (ASPs) are composed of ordinary stabilizing piles (SPs) and anchor cables and have been widely used in seismic reinforcement projects for high and steep slopes. However, the differences in the seismic responses and their underlying mechanisms caused by the installation of anchor cables remain unclear. To this end, based on two sets of centrifuge model tests, the seismic response differences of the same slope reinforced with ASPs and SPs were compared. The impact and mechanism of anchor cable installation were analyzed from multiple perspectives, including slope failure characteristics, structural internal forces and pile‒soil contact stress. Compared with SPs, ASPs showed the following results: (1) the addition of anchor cables caused abnormal acceleration amplification on the slope near the anchoring point of the pile, and seismic motion propagated along the anchor cables. (2) The stability of the reinforced slope surface was significantly improved, and the peak settlement at the top of the slope was reduced by 75.8 %. (3) The seismic soil pressure on the upper part of the pile had significantly increased, an overall 'inverted trapezoidal' distribution was observed, and the stability of the soil arch between the piles was significantly improved. (4) The residual value of the dynamic bending moment was significantly reduced, but the positive and negative peak values were not significantly different from those of the SPs. (5) Anchor cables mainly played a role in changing the load-bearing mode of the pile rather than being the main load-bearing components.