Analysis of Ground Settlement of Double-Track Tunnel Undercrossing Shallow Overburden Silt Layer

Taking the double-line shield tunnel of Zhengzhou Metro Line 12 undercrossing the shallow covered fine sand layer as the background, the construction process of the double-line shield tunnel undercrossing the shallow covered fine sand layer is simulated by using the measured data combined with the finite element analysis software. The surface settlement analysis under the con ditions of single-line tunnel, double-line tunnel penetration and different tunnel spacing is focused, and the formula calculation data are compared with the numerical simulation results. The results show that the settlement curve calculated by Peck curve formula is similar to that of numerical simulation, and the correctness of the model is proved theoretically. During the process from the left tunnel through to the right tunnel through, the position of the maximum ground settlement value shifts from the center of the left tunnel to the center of the double-line tunnel, which is due to the influence of the secondary disturbance on the soil. The maximum ground settlement decreases with the increase of tunnel spacing, and the width of settlement trough increases with the increase of tunnel spacing.