钻爆法隧道爆破振动传播规律数值模拟——以深圳白芒河引排水隧道为例

Numerical Simulation on the Blasting Vibration Propagation Induced by Tunneling Using Drilling and Blasting Method—A Case Study of Baimang River Water Storage and Sewerage Tunnel in Shenzhen

摘要: 钻爆法隧道施工所引发的振动效应会对周边建构筑物和人居环境造成不利影响，研究其传播规律对隧道安全施工具有重要意义。以深圳白芒河引排水隧道为研究对象，采用二维通用离散元软件UDEC建立数值模型，探究钻爆法隧道爆破施工过程中振动传播规律，并结合现场爆破振动监测对周围环境受影响程度进行评估。研究结果表明，质点峰值振动速度主要与爆心距有关，并受地层交界面及地表散射作用的影响；地层内部不同方向爆破振动的衰减规律差异明显；质点主振动方向受质点–爆心连线与爆破荷载施加方向夹角的影响。最后，结合模拟结果及监测数据给出地表、掌子面前方及洞室内壁爆破振动衰减系数、衰减指数及安全距离建议值。

Abstract: The blasting vibration induced by tunnel excavated using drilling and blasting method may im-pose adverse effect to the surrounding construction buildings and living environment. It is thus of fundamental importance to study the propagation of blasting vibration to ensure the safety of tunnel construction. Taking the Baimang River water storage and sewerage tunnel in Shenzhen as studied case, this paper uses the two-dimensional universal discrete element method-based software, i.e., UDEC, to establish a numerical model to investigate the blasting vibration propagation during tunnel excavation using drilling and blasting method. Afterwards, we estimate the effect degree of surrounding environment based on the numerical results together with the in-situ vibration monitoring data. The simulation results show that the particle peak velocity is highly related to its distance to the explosion center. It also influenced by the stratum interfaces and the scattering induced by shallow surface. The attenuation of blasting vibration in the stratum varies significantly in different directions. The primary vibration direction is affected by the intersection angle between the point-explosion center line and the direction of blasting loads. Finally, based on the simulation results and the field monitoring data, the paper gives the attenuation coefficient and exponent index, as well as the estimation of safety distance for the surface, excavation face and the side wall.