隧道爆破作用下邻近输油管道安全距离

为了避免隧道爆破施工时邻近地表及地下输油管道受到爆破振动造成的不良影响，需确保爆破施工工作面与输油管道保持一定安全距离。基于青岛胶州湾第二海底隧道黄岛端斜井工程，通过对斜井一期工程隧道爆破施工引起的地表振动进行监测，研究了工作面前方地表振速的衰减规律，并采用Hilbert-Huang变换及小波包分析了爆破振动频域特征。结果表明：在距工作面0～40 m的高振速区范围内，振速呈现震荡变化，峰值合振速出现在距工作面一定距离的地表区域，而在高振速区之外部分呈指数衰减趋势；爆破振动的频域分布主要集中在0～200 Hz的低频区域，50 Hz左右为其最集中区域，瞬时能量峰值出现在0～1 s内，其中在0～25 Hz范围内能量占比最高为13.41%,与输油管道自振频率范围存在部分重叠。同时，引入萨道夫斯基修正公式并拟合出适用于本工程条件下的振速预测公式模型，从法律规范、工程实践及抗震能力3个方面考虑提出输油管道安全振速为1 cm/s,计算得到50 m范围内最大单段齐爆药量和安全距离之间的关系，为后续斜井二期工程下穿输油管道区域时的爆破方案优化提供参考。

Study on the safety distance of adjacent oil pipelines under the action of tunnel blasting

In order to avoid the adverse impact of blasting vibration on the adjacent surface and underground oil pipeline during tunnel blasting construction, it is necessary to ensure that the blasting construction face is kept at a safe distance from the oil pipeline. Based on the inclined shaft project at Huangdao end of Qingdao Jiaozhou Bay Second Submarine Tunnel, this paper monitors the surface vibration caused by the blasting construction of the first phase of inclined shaft project. The attenuation law of ground vibration velocity in front of the working face is studied, and the frequency domain characteristics of blasting vibration are analyzed by HHT and wavelet packet. The results show that the vibration velocity in the range of 0~40m away from the working face presents a tendency of vibration variation. The peak combined vibration velocity appears in the surface area at a certain distance from the working face, while the part outside the high vibration velocity area shows an exponential attenuation trend. The frequency domain distribution of blasting vibration is mainly concentrated in the low frequency area of 0~200Hz, and about 50Hz is the most concentrated area. Instantaneous energy peak appears within 0~1s. Among them, the energy accounts for 13.41% at most in the range of 0~25Hz, which is partially overlapped with the natural frequency range of oil pipeline. At the same time, Sadovsky''s modified formula is introduced and the vibration velocity prediction formula model applicable to the conditions of the Project is fitted. Considering the legal norms, engineering practice and seismic capacity, it is proposed that the safety vibration velocity of the oil pipeline is 1cm /s, and the relationship between the maximum single section homogeneous explosive quantity and the safety distance within the range of 50m is calculated, which provides a reference for the blasting scheme optimization when the following Phase II inclined shaft project passes through the oil pipeline area.