全断面开挖爆破产生的自由面对振动频率的影响研究

发布时间：2018-02-14 15:54

本文关键词： 地下洞室爆破自由面振动频率　出处：《振动与冲击》2016年07期 　论文类型：期刊论文

【摘要】：通过对爆破试验中处于不同自由面条件下的炮孔爆破产生的振动信号进行频谱分析,并结合爆破振动数值模拟,研究了地下洞室全断面毫秒延迟爆破过程中产生的自由面对振动频率的影响机理及变化规律。结果表明:爆炸荷载产生的压应力波传播至自由面时发生反射,反射稀疏波与原应力波叠加致使远区荷载压力的上升时间和持续作用时间变短,造成荷载的频率变大,从而导致有自由面条件下其振动频率增大、高频振动能量占总能量的比重增加;爆源与自由面之间的距离越小,爆破振动频率越高;从振动频率的角度来看,较好的自由面条件可以减小爆破振动对结构的破坏。试验监测结果验证了分析结论的可靠性。
[Abstract]:By analyzing the frequency spectrum of the vibration signal produced by blasting under different free surface conditions in blasting test, and combining with the numerical simulation of blasting vibration, In this paper, the influence mechanism and variation law of the free face vibration frequency produced during the full section millisecond delay blasting of the underground cavern are studied. The results show that the compressive stress wave produced by the explosion load propagates to the free surface, and the reflection occurs when the pressure stress wave propagates to the free surface. The superposition of the reflected sparse wave and the original stress wave makes the rise time and duration time of the load pressure in the far area shorter and the frequency of the load become larger, which leads to the increase of the vibration frequency under the condition of free surface. The ratio of the high frequency vibration energy to the total energy increases; the smaller the distance between the explosion source and the free surface, the higher the blasting vibration frequency. Better free surface condition can reduce the structural damage caused by blasting vibration, and the reliability of the analysis conclusion is verified by the experimental monitoring results.
【作者单位】：南昌大学建筑工程学院;武汉大学水资源与水电工程科学国家重点实验室;
【基金】：国家自然科学基金资助项目(51509126;51279135)
【分类号】：TV542

【相似文献】