DYNAMIC RESPONSE OF REINFORCED EARTHEN EMBANKMENTS

Abstract

Soil is good in taking compression and weak in tension. On the other hand, reinforced earth is strong in compression as well as tension. It also exhibits ductility. As such, it is ideal for earthquake resistant design of embankments. The main aim of investigation is to propose a suitable analytical method under the dynamic conditions for the R.E. embankment. The testing of large prototype of R.E. embankments under seismic loading conditions requires huge experimental setup. In the present study dealt with 2D linear finite element method of analysis in time domain under plain strain conditions. The responses from analytical investigation have been compared with experimental response on of large scale embankment subjected to same base excitation from tests carried out on R.E. embankments using shake table by Siavoshnia (1998). The embankment was discretized into 6, 18 and 30 layers. The results of analysis indicate that for the idealization with 30 layers, the maximum error in computed response is limited to 30% only and the weighted average error of response is only 20% to 25% for 0ME=24. If the input values of `G' are revised in the light of strain levels computed at the end of 1St cycle of analysis and the analysis is repeated. The maximum error in results of analysis will be of the order of 24% only and weighted average error is . 12% only. Similarly this results with base excitation corresponding to 0ME=36 are much more reasonable with maximum errors less than 20% and weighted average error of the order of 10% only.