Impact of Pile Head Rigidity on the Response of Piled Raft in Sand Under Pseudo-Static Loading

Abstract

The 3D finite element simulations are carried out to study the impact of different pile head connection conditions, i.e., rigid and hinged connection on the response of piled rafts in sand subjected to pseudo-static horizontal loading. The time-acceleration histories of Assam (2014), Bhuj (2001), Sikkim (2011) and Uttarkashi (1991) earthquakes are considered to calculate the horizontal pseudo-static loads. Analyses results confirm that pile head connection rigidity greatly influences the behavior of piled raft in many aspects. The horizontal stiffness of piled raft is found to decrease as the rigid pile head connection changes to hinged one. Piles in a piled raft foundation is found to carry about 52–75% of the pseudo-static horizontal load for rigid connection and 32–48% for hinged connection. The horizontal deflection of pile is found maximum at the pile head and becomes negligible along the depth of pile for both cases. For rigidly connected piles, the maximum bending moment occurs at the pile head, whereas piles with hinged connection show zero bending moment at top and maximum value at a certain depth from pile head.