Dynamic Response of Pile Foundation Subjected to Different Frequencies in Sandy Soil

Abstract

This research presents an experimental study of the dynamic response of pile foundation as a result of the vibration of a nearby foundation as a source of dynamic load in sandy soil with relative density of 85%. The experiments were conducted on dry and soaked state of soil. The pile raft consisted of a pile cap with dimensions of (100 x 100 x 10) mm, connected with four solid steel piles with a slenderness ratio of 30 and pile diameter is 8 mm, and the machine foundation (vibration source) with dimensions (80 x 80 x 40) mm. After having completed the soil layers preparation inside a steel container with suitable dimensions is used, the machine that generated vibration was operated by the rotating mass, as this vibration reached the pile raft. The results showed that the displacement amplitude, acceleration, velocity and settlement of the pile raft decreased with increasing distance with the vibration source (from 0.5B to 2B) for the three frequencies (10,15 and 20) Hz, while the decrease for displacement was (48%,23.83% and 42.48%) respectively in the dry state of soil. On the other hand, the decrease for displacement was (37%, 23.16% and 46.27%) in the soaked state of soil. Regarding acceleration, it was decreased to (29.66%, 45.79% and 40.38%) respectively in the dry and (100%, 21.88% and 34.04%) in the soaked state of soil. Furthermore, the velocity reached (45.38%, 42.96% and 38.18%) respectively in the dry and (54.05%, 11% and 28%) in the soaked state of soil, the settlement was (63.82%, 52.1% and 38.18%) respectively.