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详细分析了导流隧洞地质条件,结合隧洞的布置特点和现场的施工情况,采用固定测点的方案,对隧洞开挖施工进行了现场监测。分析测试数据发现,质点振动速度具有明显的方向效应,质点朝临空面的振动速度明显大于其他方向。测点和爆点不在同一高程时,当两点的高差与爆心距的比值较大时,“高差效应”引起的质点在不同方向的峰值振动速度差别十分明显,当两点的高差与爆心距的比值较小时,“高差效应”明显减弱。对于高差与爆破振动传播和衰减规律之间的关系,以往的研究提出了一些修正公式,但这些公式均把高差作为一个独立的变量进行考虑,物理意义不甚明确。根据前面的数据分析,考虑高差影响的实际意义并结合无量纲分析,取高差与爆心距的比值作为“高差效应”影响因子,对传统爆破振动波衰减经验公式进行了修正,经过对比分析,修正后的爆破振动波衰减规律公式具有更高的精度。同时,对实际监测中出现的振动速度超过安全控制速度的情况进行了分析,及时调整爆破参数,从而有效地控制了爆破振动破坏效应。其研究成果对指导隧道工程开挖爆破施工和保证坝体及大坝帷幕安全起到了重要作用,保证了该工程爆破施工的顺利完成。
The geological conditions of the diversion tunnel are analyzed in detail. According to the layout characteristics of the tunnel and the construction conditions of the site, the scheme of fixed measuring point is used to monitor the tunnel excavation. Analysis of the test data shows that the particle vibration velocity has a significant directional effect, and the vibration velocity of the particle toward the free surface is obviously larger than other directions. When the measuring point and the explosion point are not at the same elevation, the difference of the peak vibration velocity in different directions caused by “height difference effect ” is very obvious when the ratio of the height difference between the two points and the burst center distance is large. When the ratio of height difference and burst distance is small, “height difference effect ” obviously weakened. For the relationship between height difference and the law of propagation and attenuation of blasting vibration, some corrections have been proposed in previous studies. However, these formulas take height difference into account as an independent variable, and their physical meaning is not clear. According to the above data analysis, taking into account the practical significance of elevation difference and combining with dimensionless analysis, taking the ratio of elevation difference and burst center distance as the influence factor of “height difference effect”, the empirical formula of traditional blasting vibration attenuation is modified, After comparative analysis, the modified formula of attenuation law of blasting vibration wave has higher accuracy. At the same time, the actual monitoring of the vibration speed exceeds the safety control speed of the situation were analyzed, timely adjustment of blasting parameters, thus effectively controlling the destruction of blasting vibration effect. The research results have played an important role in guiding the excavation and blasting construction of the tunnel project and ensuring the safety of the dam and the dam curtain, which ensures the successful completion of blasting construction of the project.