隧道下穿运营机场跑道的爆破振动安全判据研究

以我国第一座采用钻爆法下穿运营机场跑道的隧道恩施金凤大道许家坪隧道工程为依托,开展对机场跑道的爆破动力安全判据的研究。首先基于应力波传播理论及极限拉应力准则,对爆炸应力波传播至机场跑道上表面(即自由面)处发生的反射进行理论分析,建立基于混凝土跑道结构安全的爆破振动速度判据模型,并提出跑道的爆破振动速度安全阈值;同时,基于数值模拟,从统计角度建立拉应力峰值与质点振动速度峰值之间的函数关系,求解得到机场跑道的爆破振动速度安全阈值。最后,将理论分析结果、数值计算分析与《爆破安全规程》进行对比分析,最终确定机场跑道的爆破振动速度安全判据,为在隧道下穿机场跑道爆破施工提供了依据。

Blasting Vibration Safety Criterion for Tunnel Under-passing Airport Runway

The blasting vibration safety criterion for the tunnel under-passing an airport runway is studied with reference to Xujiaping Tunnel,which is the first tunnel constructed by drilling and blasting under a running airport runway. First,based on the stress wave theory and the failure law of maximum tensile stress,the reflection of a P-wave on the upper surface of airport runway( a free surface) is analyzed,the blasting vibration safety criteria model is established and the blasting vibration safety threshold for airport runway is proposed. Then,the safety threshold of peak particle velocity( PPV) is decided based on the statistic relationship between the peak value of tensile stresses and the PPVs on the runway. At last,the theoretical analysis results and numerical calculation results are compared with the Safety Regulations for Blasting to finalize the safety criterion for the blasting of the tunnel crossing under the airport runway.