Abstract: To reveal the propagation law of blasting vibration and the structural response characteristics of existing buildings under-crossed by a shallow-buried muddy sandstone tunnel, the building-under-crossing section of the He Dashan Tunnel on the newly built Chengdu–Dazhou–Wanzhou Railway was taken as the engineering background. Field monitoring, numerical simulation, and regression analysis were combined to investigate the three-directional attenuation characteristics of blasting vibration in muddy sandstone strata, the control effect of reduced charge, and the deformation response of the under-crossed buildings. It was shown that the critical maximum charge per delay in the building-under-crossing section of the He Dashan Tunnel was 4.90 kg. Under the original charging condition, the Z-direction peak particle velocity at the nearest building was recorded as 1.62 cm/s; after charge reduction, it was reduced to 0.85 cm/s, which corresponded to a reduction of approximately 47.5%. Under shallow-buried muddy sandstone conditions, obvious spatial anisotropy was observed in blasting vibration, and the Z-direction vibration velocity was identified as the dominant response for controlling blasting vibration safety of the buildings. The vertical site coefficient Kz, attenuation exponent αz, and coefficient of determination R2 were 397.13, 1.99, and 0.95, respectively, indicating that the vertical vibration in this stratum was characterized by strong near-field response and rapid spatial attenuation. After the adoption of Φ76-mm pipe-roof advance support and the three-bench temporary transverse bracing method, the maximum vertical settlement of the buildings was 1.29 mm, the maximum local inclination was 0.000018, the cumulative surface settlement was mainly in the range of 8–15 mm, and the tunnel deformation generally tended to stabilize. An integrated control system was formed by reduced charge, advance support, and staged excavation, which could provide a reference for similar shallow-buried muddy sandstone tunnels under-crossing buildings.
曹彦龙. 泥质砂岩浅埋隧道爆破振动衰减特征及下穿结构响应分析[J]. 隧道与地下工程灾害防治, .
CAO Yanlong. Analysis of blasting vibration attenuation characteristics and structural response of a shallow-buried muddy sandstone tunnel under-crossing buildings. Hazard Control in Tunnelling and Underground Engineering, 0, (): 1-9.
