Abstract: In complex urban environments, tunnels are frequently excavated beneath high-rise buildings with pileraft foundations. This study aims to reveal the interaction mechanism between the tunnel, surrounding soil, and piled raft foundations to achieve accurate prediction and assessment of environmental effects induced by tunnel construction. Three-dimensional numerical models were established using the ABAQUS finite element software to investigate the dynamic evolution and load-transfer behavior of pile-raft foundations due to tunneling-induced disturbances in sandy soil. An advanced hypoplastic constitutive model was adopted to simulate the deformation response of soils subjected to tunneling. Vertical loading tests on single piles and piled raft foundations were simulated to obtain load-displacement relationship curves and bearing capacities, with accuracy validated against centrifuge test results. Tunnel construction was simulated using tunnel volume loss methods to obtain the variations in base load, shaft resistance, and raft load for both single-pile (raft) and group-piled raft foundations, thereby clarifying the role of the raft on tunnel-soil-pile interactions. The results show that tunneling-induced settlements on single pile-raft foundations is significantly smaller than that of single piles. Both foundations directly above the tunnel exhibit greater settlement than greenfield surface settlement, while eccentric foundations show reduced settlement. As the tunnel volume loss increased, upward migration of the soil arching amplifies lateral soil pressure on piles and the shear stress at soil-pile interface, consequently enhancing shaft friction in the upper sections of central piles; however, this stress disturbance is negligible under eccentric conditions. Under constant working loads, for the central pile foundation, the load previously resisted by the end-bearing component is gradually taken over by the shaft resistance, whereas for the piled raft foundation, the load resisted by the end bearing is mainly transferred to the raft to maintain stability—a trend reversed under eccentric loading. Dynamic load redistribution occurs among piles in group-raft systems due to raft deformation: loads on external piles gradually decrease and transfer to central piles for the eccentric piled raft foundation, further intensifying interactions within the tunnel-soil-pile-raft system. The dynamic evolution and deformation of pile-raft foundations under tunneling disturbances are collectively governed by relative soil-pile settlement, soil stress unloading at the pile base, and raft deformation. This study provides useful guidance for the risk assessments in urban underground construction.