Centrifugal Model Tests on Deformation Characteristics of Geosynthetics Reinforced Soil Abutment

Abstract:

Five centrifugal model tests were conducted to investigate the deformation characteristics of geosynthetics reinforced soil （GRS） abutment under service conditions. The setback distance （i.e.， the distance from the beam seat to the inner of the facing） and beam seat width were considered as two influencing factors. The GRS abutment was loaded through multi-stage loading in centrifugal field. Test results indicate that the deformation of the GRS abutment is closely related to the setback distance and the beam seat width. The deformation decrease as the setback distance increases， there exists an optimal setback distance， beyond which the effect on controlling the abutment deformation becomes minimal. The deformation increase as the beam seat width increases under the same load. In addition， the maximum reinforcement strain decreases as the setback distance increases， and increases as the beam seat width increases. At each reinforcement layer， the maximum strain occurs below the beam seat and gradually transitions toward the setback area along the facing. Additionally， the peak strain at each reinforcement layer also decreases from top to bottom. The volumetric strain of GRS abutments in all tests is less than 0.15%， and the assumption of “zero volumetric strain” can still be used for GRS abutments. There is a significant deviation between the calculated values of the maximum horizontal displacement given by the existing specification and the measured values， which cannot well reflect the influence of setback distance and beam seat width， indicating the need for further optimization. The results can provide references and basis for the design of GRS abutments and the formulation of relevant specifications.