Instrumentation for bender element testing of soils

Abstract

Determination of shear wave velocity in sands is necessary for safety of various civil engineering structures. With this in view, earlier researchers have employed, mainly, resonant column and bender elements to determine this parameter. However, resonant column tests can only be performed in especially designed apparatus, which is not only expensive but large in size too. While, bender elements, which can easily be fitted in any conventional test setup, have been found to be quite efficient for this purpose. However, bender elements employ quite sophisticated and costly circuitry, which makes them beyond the reach of many. This calls for development of a simple setup for determining shear wave velocity in soils, which is simple, cost effective, easy to use and non-invasive also. With this in view, efforts were made to develop an electronic circuitry, which can be employed for determining shear wave velocity in sands and its details are presented in this paper. Based on the experimentation on different sand specimens, shear wave velocity in sand was obtained. These values are found to be in the same range as reported in the literature, which demonstrates the utility of the circuitry and methodology developed by the authors and reported in the literature.