One of the undesirable effects of water leaking into a tunnel is the loss of fines from the ground behind the tunnel lining. The loss of fines creates erosion voids around the tunnel which alter the stress distribution on the lining. Excessive loss of fines due to water leakage would lead to serious stability issues about the tunnel structural stability. This study looks into a case where multiple tunnels constructed in weathered basaltic rocks and evaluates the effects of fine loss on circumferential stresses and bending moments in the tunnel lining using finite element modeling techniques. Analytical results from the finite element modeling show that the extents and the void locations as well as the combination of multiple voids will have significant impacts on the tunnel lining, and hence the engineering performance of the tunnel.