Large scale shaking table test on seismic behaviors of geogrid reinforced retaining walls under near-fault and far-field ground motions

The dynamic behavior and the aseismic mechanism of the geogrid reinforced retaining wall at present have not been understood very well. The laminar shear container of soil was used for the test model of the geogrid reinforced retaining wall, and its seismic behaviors were investigated by a large scale shaking table test. The similarity criterion of the test model was based on the Froude constant of π theorem. Under the near-fault and far-field ground motions, the SP far-field wave, the SF near-fault wave during Wenchuan earthquake and Taft mid-far-field wave were applied to studying the seismic behaviors of the geogrid reinforced retaining wall, including the wall acceleration, the acceleration of reinforced backfill soil, the lateral deformation of wall, the seismic subsidence of the backfill ground surface in the reinforced zone and unreinforced zone, the excess pore water pressure in reinforced backfill soil and strain characteristics of geogrid. The measured results show that the geogrid reinforced retaining wall exhibits strong macroscopic seismic response characteristics under the far-field and mid-far-field ground motions, while the test model exhibits strong microscopic seismic response characteristics under the near-fault ground motion. The seismic response characteristics of the acceleration and the subsidence may indicate that the geogrid layers play an important role in improving the seismic resistance of the retaining wall. The distribution characteristics of the geogrid strain may reveal the force distribution law along the flexible retaining wall. ©, 2015, Editorial Office of China Civil Engineering Journal. All right reserved.