Analysis of Mutual Influence on Blasting Construction of Urban Shallow-buried Small Spacing Tunnels

Relying on the ten-mark project of Fuzhou Rail Transit Line 2, after the right-line tunnel was excavated for 25m, the left-line tunnel was excavated, and the three-dimensional tunnel calculation model was established by the finite element analysis software Ls-dyna. The stress of the right-line tunnel lining, the ground vibration velocity and the vibration velocity of the right-line tunnel were analyzed to evaluate the influence of the left-line blasting excavation on the right-line tunnel, and verified with the on-site monitoring data. The results showed that when the maximum dose of single hole was 2kg, the left tunnel blasting excavation analysis was carried out when the minimum spacing of the two tunnels was 1.6m, the maximum stress generated on the right tunnel was 2.762MPa, The maximum stress generated on the right-line tunnel was 2.762 MPa, which had exceeded the tensile strength of the concrete; the maximum vibration velocity generated on the ground at the top of the left-hand tunnel was 13cm/s, which exceeded the relevant control requirements; the maximum vibration velocity generated by the right arch waist was 32cm/s, which had a great influence on the right-line tunnel.