Vibration behaviour of X section piles subjected to machine induced harmonic loading- experimental study

Pile foundations are considered as superior choice in this booming era for supporting heavy industrial machines. Recent advancements necessitates modification of conventional pile foundations to improve its performance without additional costs. This idea led to the development of non-conventional piles. Therefore, this study entails experimental analysis of non-conventional X section pile (XCC) and conventional circular piles of same area under dynamic loading and its comparative analysis. Forced vibration test has been performed on steel piles of length 1.4 m, under vertical and horizontal vibrations in sand and clay for four distinct eccentric moments (0.0157 N-m, 0.0235 N-m, 0.0314 N-m, 0.0392 N-m). The responses are acquired in terms of frequency- amplitude responses and it shows that under both type of loadings and soil conditions, XCC pile is performing superior to circular pile. This can be due to its widened perimeter, complex geometry and additional confinement offered by the concave portion. However, on comparing the performance of XCC piles under different loads and soil conditions, the responses manifested an excelled performance in sand as compared to clay. This can be due to the high stiffness attained by sand during vibration, whereas, vibration in clay loosens the soil-pile bond and ultimately reduces the soil-pile stiffness.