Modification of the Peck Formula for a Double-Track Shield Tunnel under Expressway Subgrade

In practice, asymmetric formation disturbance occurs due to the sequence of excavation though parallel double-track tunnel is a typical symmetrical engineering. Based on shield tunneling project section Suzhou Rail Transit under subgrade Shanghai–Nanjing Expressway, finite element model was established obtain numerical solution that validated by measured data guarantee reliability. According construction characteristics method, two correction coefficients—namely soil loss rate coefficient ? and settlement trough width ?—were introduced. A modified Peck formula suitable for preceding subsequent proposed. The applicability verified another similar project. results showed can better reflect actual highway tunneling. calculated classic had large error in comparison with data. empirical could more accurately predict expressway caused method when ?1 = 0.38 ?1 2.08 ?2 0.29 ?2 1.99 tunnel.