新型水封爆破除尘技术试验研究

为更快速有效地清除隧道钻爆施工所产生的粉尘，提出“辅助降尘注水孔方案”、“差异水袋布置方案”、“降尘注水孔+差异水袋布置” 3种新的水封爆破除尘技术方案。依托轿顶隧道进行现场试验，得到初始状态下掌子面区域纵、横向特征位置的粉尘质量浓度，CO、CO2、O2、NO2体积分数分布情况，通风条件下纵向特征位置的粉尘质量浓度、CO体积分数随时间的变化规律，3种新型水封爆破方案下掌子面区域纵、横向特征测试位置的粉尘质量浓度、CO体积分数分布规律。经研究得出如下结论： 1）通风10 min内是粉尘质量浓度、CO体积分数下降最快的阶段； 2）新型水封爆破除尘方案的降尘效果明显，3种方案最大降尘比例依次为36.84%、40.85%、65.74%； 3）降尘注水孔对爆破粉尘可起到良好的“封闭”作用； 4）新型水封爆破方案可起到明显降低CO体积分数的作用。

Experimental Study on New Hydraulic Blasting Dust Removal Technology

In order to remove the dust produced by the tunnel drilling and blasting construction more quickly and effectively, three new dust removal technical schemes, i.e. auxiliary dust reduction water injection hole, differential water bag arrangement, and dust reduction water injection hole + differential water bag arrangement, are proposed, and field test is carried out on Jiaoding Tunnel. The test results obtained are as follows: the concentration distribution of dust, CO, CO2, O2 and NO2 in the longitudinal and transverse characteristic positions of the tunnel face area in the initial state, the variation rules of dust and CO concentration in the longitudinal characteristic positions with time under ventilation conditions, and the concentration distribution of dust and CO in the longitudinal and transverse characteristic test positions of the tunnel face area under three new hydraulic blasting schemes. Some conclusions are drawn as follows: (1) The concentration of dust and CO decreases fastest within 10 minutes of ventilation. (2) The dust reduction effect of the new scheme of hydraulic blasting is obvious, and the maximum dust reduction ratios of the three schemes are 36.84%, 40.85% and 65.74%, respectively. (3) The dust reduction water injection hole can play a good role in "sealing" the blasting dust. (4) The new scheme of hydraulic blasting can significantly reduce the CO concentration.