EFFECT OF WALL ASPECT RATIO ON SEISMIC RESPONSE OF NARROW MECHANICALLY STABILIZED EARTH WALLS

Document Type : Original Article

Authors

1 Cairo University and Teaching Assistant, Scientific Research Developing Unit, Beni Suef University, Egypt

2 Public Works Department, Cairo University, Egypt

Abstract

Increasing population and expanding urban development in 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. When constructed in seismically active zones, these walls are subject to seismic ground motions. The purpose of this paper is to present the results of small scale shaking table tests on NMSE walls with rigid facing. A series of reduced scale (1/8 of the prototype model) shaking table tests are performed on a 1-dimensional shaking table. The modeled walls have aspect ratio (L/H) of 0.20, 0.30 and 0.40. The model is shacked using ramped sinusoidal base accelerations with incrementally increasing displacement amplitude (i.e. actuator stroke) and constant frequencies to generate an equivalent base acceleration ranging from 0.05 g to 0.70 g or until failure occurs. Ground motion frequency of 2.5 Hz is used. The results show that at input accelerations ranging from 0.25g to 0.45g yielding occurs and the NMSE walls behaves as a rigid body. Subsequently, excessive deformations occur due to the pull out of the top reinforcement layers. An amplification factor of 2.50 times the input ground motion is measured at the surface of the NMSE models. Furthermore, the average design acceleration for the model walls ranges from 1.02 to 1.35 of the input base acceleration.

Keywords

Journal of Al-Azhar University Engineering Sector
Volume 13, Issue 49
October 2018
Pages 1220-1228

Files

Share

How to cite

Statistics