Laboratory Investigation on Wave Characteristics Due to Hammer Impact on Different Types of Soil

Abstract

Pile foundations are suitable when the surface soil is fragile, and the load coming from the superstructures is very high. Direct Mud Circulation (DMC) method of piling was considered as the most reliable piling system all over the world. The chiseling action in DMC piling produces stress waves, and these waves may cause problems to the nearby structures. This paper deals with a laboratory model study to investigate the vibration propagation and attenuation characteristics of different types of soil at various test parameters. The responses of soil surface due to impact load were studied, and results showed that the various factors controlling the wave propagation of soil include the distance of impact from the source, relative density of soil, impact hammer energies. The peak vertical acceleration was measured using a triple-axis accelerometer placed at different positions and with the help of SeismoSignal software version 4.3, the corresponding peak particle velocity and displacements were evaluated. The soil dependent parameters k and n were found out from the peak particle velocity, and an attempt is made to develop an equation to predict vibrations on the tested soils.