<p>This study investigates the effect of side-by-side twin tunnels on a pile group in dry clay using the finite element method, considering tunnel lining. To validate the numerical model, ground surface settlement, settlement above the tunnel axis, and axial forces in the pile group were compared with existing literature. The results show that the settlement of the pile cap head was smaller for the second tunnel than for the first. Maximum settlement and tilting occurred when the tunnels were positioned below and around the pile toes, respectively. The greatest change in pile head load (22%) was observed in the pile closest to the tunnel when the first tunnel was constructed near the pile toes. These effects were most pronounced with the largest tunnel diameter and the shortest distance between the tunnels. Twin tunneling near the pile group led to different load transfer mechanisms: downward transfer when the tunnels were near the pile toes, upward transfer when they were beneath the pile group, and a combination of both when the tunnels influenced load distribution in multiple directions.</p>