College of Engineering

A Master thesis was discussed in Department of Civil Engineering / College of Engineering at University of Mosul entitled “Study the Response of Pile Foundation to Dynamic Load” submitted by (Noor Qosay Abd-alqhani Hassan), Supervised By Prof. Dr. Bayar J. Al- Sulayvani and Dr. Mohammed N. Jaro on Thursday, Oct. 27, 2022.The thesis aimed to calculate the vertical amplitude of group pile – cap system subjected to dynamic machine loading analytically based on some special formulas and numerically using PLAXIS 3D V.20 program package. The effect of each of machine operating frequency, pile diameter, pile length, ratio of embedment depth of pile cap and depth of bedrock on the vertical amplitude of the group pile – cap system were studied.It was found that, generally and by using analytical method, the maximum vertical amplitude of group pile – cap system decreases by increasing the pile diameter, pile length, embedment ratio of pile cap and by decreasing the depth of the bedrock. Unlike the analytical method, the maximum vertical displacement calculated numerically increases by increasing pile diameter. It can be also observed that the ratio of operating machine to natural frequencies (ω/ωn) corresponding to maximum vertical amplitude decreases (the group pile – cap system is moving away from the resonance condition) with increasing of pile diameter and ratio of pile cap embedment. The Normalized Value was also investigated to estimate the efficiency of group pile – cap system subjected to dynamic machine loading regarding to resonance condition.The results indicated that, the Normalized Value increases with increasing pile diameter. The Normalized Value of the system with surface cap is less than these of embedded cap. It can also find that for all investigated values of pile diameter, pile length, ratio of embedment depth of pile cap and some values of depth of bedrock, the lowest values of Normalized Value occur at middle range of machine operating frequency values, almost between 60 – 140 rad/sec.