Behavior of anchorage narrow mechanically stabilized earth walls under seismic loading

Civil Engineering Dep., Faculty of Engineering, Beni- Suef University, Beni- Suef, Egypt Ahmed011285@eng.bsu.edu.eg

Abstract

The rapid increasing and development of infra-structures in Egypt in very limited spaces involves construction of Narrow Mechanically Stabilized Earth (NMSE) walls having an aspect ratio (ratio of reinforcement length, L, to wall height, H) below 0.70. These walls are constructed Infront of existing rigid faces and the top reinforcement layer is fixed to the face by mechanical connections. These walls are subjected to dynamic loads when constructed in active seismically areas. The purpose of this paper is to present a typical -one- reduced scale (1/8 of the prototype model) shaking table test of (L/H) equal 0.30. The model is shaken using stepped sinusoidal base accelerations with incrementally increasing displacement amplitude and constant frequencies to generate an equivalent base acceleration ranging from 0.05 g to 0.80 g or until failure occurs. The frequency of the wave is 2.50 Hz. The results of the tests displays that the yield acceleration of the tested wall is about 0.48g. The results of NMSE walls with reinforcement anchorage resulted in yield acceleration higher than 26 % when correlated to the published NMSE walls without reinforcement anchorage. Finally, 1.25 average amplification factor can be used in the seismic design of NMSE walls of similar configurations.