TY - JOUR AU - Mei, Yuan AU - Liu, Ziyang AU - Zhou, Dongbo AU - Wang, Yifei AU - Zhang, Yuhang PY - 2026 TI - Modification of the Peck Formula for Double-Line Large-Diameter Slurry Shield Tunnels in Composite Strata JO - Chinese Journal of Underground Space and Engineering SN - 1673-0836 SP - 788 EP - 799 VL - 22 IS - 3 AB - With the acceleration of urbanization, underground space development has become an important way to relieve the pressure of urban traffic. In composite formation, the construction of a double-line large-diameter mud-water shield tunnel faces complicated geological conditions and construction problems. Based on the measured surface settlement data of a double-line tunnel project in Hangzhou, this study adopts a mathematical method to perform regression analysis and introduces the correction coefficient α of the maximum surface settlement and the correction coefficient β of the width of the settlement trough to correct the double-line Peck formula. Meanwhile, combining the superposition principle, an applicable correction method for the superposed section of the double-line tunnel in composite formation is proposed. In order to accurately predict the ground settlement law of double-line large-diameter mud-water shield tunnel construction in composite formation. The results show that there is a great difference between the measured value and the predicted value of the Peck formula of the double-line large-diameter mud shield before correction. Examples show that the superposition section correction method can effectively improve the fitting degree of the superposition section prediction curve when the center distance L of the two-track tunnel is greater than (i left +i right). By comparing the corrected coefficient range ofthe Peck formula with different diameters, it can be seen that the large-diameter shield is better than the small-diameter shield in vertical settlement control, and the distribution range of the corrected coefficient of sedimentation tank width is larger than that of the small-diameter shield. The research can provide a reference for the design and construction of large-diameter shield tunnels in China. UR - https://doi.org/10.20174/j.JUSE.2026.03.05 DO - 10.20174/j.JUSE.2026.03.05