Abstract:
This paper investigates the shielding effect within piles in a group adjacent to deep unbraced and braced
excavations. Numerical simulations based on the finite element method are performed on free-head
and capped-head piles in three different pile group configurations. The numerical model is validated by
simulating a series of centrifuge tests. The problem was modelled considering the three-dimensional
geometry, which facilitates to simulate the shielding effect of piles within the group during an excavation.
Results show that the presence of front piles near the excavation face reduces the detrimental effects on
the rear piles within the group in unbraced excavations. In addition, the provision of a pile cap significantly
reduces the deflection of pile group in unbraced excavations due to load transfer to rear piles, which are
located away from the excavation. However, in braced excavations, unless the excavation is deep, the
shielding effect and the presence of a pile cap are less significant on the pile group behaviour.
