成贵铁路白杨林高瓦斯隧道施安全关键技术研究

发布时间：2018-03-20 21:50

本文选题：高瓦斯隧道　切入点：施工安全　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：我国西南部多为山区,煤炭资源丰富,煤层分布较多。当隧道穿越煤层地区时,由于煤质岩层作为围岩的条件太差,而且常常伴随瓦斯的突出,导致隧道的修建难度和成本大大增加。瓦斯隧道的施工具有较大的施工风险,事故发生后果严重。为保证瓦斯隧道的施工安全,穿越煤层过程中必须采取有效的防突措施,降低煤层内瓦斯压力;选择合理的通风方式,防止瓦斯浓度过高,同时需要对隧道内的设备进行防爆改装。本文以白杨林高瓦斯隧道为依托工程,研究高瓦斯隧道施工通风中的流场规律以及瓦斯浓度分布,对现场的通风方式进行优化,并通过现场测试对通风效果进行评估。同时对防爆改装机械和非防爆改装机械进行了动力性能试验,得出防爆改装对施工机械动力性能影响程度。本文主要结论如下:(1)施工通风风管位于拱腰,风管末端距掌子面为5m～13m时,瓦斯的最大浓度出现在右侧,小于0.5%,掌子面负压区所占比例超过掌子面面积的60%,瓦斯能够顺利排出。因此,供风量不变的情况下,风管末端距离掌子面为5m～13m时通风效果和瓦斯稀释效果理想。(2)钻孔直径、进煤深度、抽排压力均影响煤层瓦斯的抽排效果。增大钻孔直径、增长进煤深度、增大抽排压力均可以使瓦斯抽排的有效半径增大,影响范围增大,抽排量增多。经过不同工况下的研究,结合现场实际情况,得出钻孔直径在75～100mm,抽排压力为-20～-30kPa,进煤深度在1.5～2.5 m之间时,瓦斯抽排效果最好。(3)随着钻孔孔底之间距离的增加,钻孔之间的相互影响作用减弱。以抽排率作为判断标准,得出抽排工期与孔底间距之间的关系。建议白杨林隧道DK474+138～188处煤层孔底间距为取2m,抽排工期为70d。(4)防爆改装对于工程机械的动力性能影响明显。同型号的改装机械与非改装机械,在相同测试条件下,对于运输类机械来说,达到相同速度时,改装机械的耗时约为非改装机械的2倍,加速性能降低,平均加速度下降15%,功率下降15%～30%。对于液压类机械来说,防爆改装后输出功率下降15%～20%,机械臂的平均移动速度下降33%。
[Abstract]:Most of the southwest of China is mountainous area with abundant coal resources and more coal seams. When the tunnel passes through the coal seam area, because of the poor condition of coal strata as surrounding rock, and often accompanied by gas outburst, In order to ensure the safety of gas tunnel construction, effective anti-outburst measures must be taken in order to ensure the construction safety of gas tunnel. Reducing the gas pressure in coal seam, choosing reasonable ventilation mode, preventing gas concentration too high, at the same time, the equipment in the tunnel should be explosion-proof and refitted. In this paper, based on the high gas tunnel of poplar forest, The flow field law and gas concentration distribution in construction ventilation of high gas tunnel are studied, and the ventilation mode in the field is optimized. At the same time, the dynamic performance tests are carried out on the refitted and non-explosion-proof machines. The main conclusions of this paper are as follows: 1) the construction ventilation duct is located at the arch waist, and the maximum concentration of gas appears on the right side when the end of the duct is 5 m or 13 m from the palm surface. Less than 0.5, the proportion of the negative pressure area on the palm surface is more than 60 percent of the area of the palm surface, and the gas can be discharged smoothly. Therefore, when the air supply volume is constant, the ventilation effect and the gas dilution effect are ideal at the end of the air duct when the distance between the end of the air duct and the palm surface is 5 m or 13 m.) the diameter of the borehole is ideal. The effective radius and influence range of gas drainage can be increased by increasing the diameter of borehole, increasing the depth of coal and increasing the pressure of drainage. Through the research under different working conditions, combined with the actual situation on the spot, it is concluded that when the diameter of the borehole is 75 ~ 100mm, the drainage pressure is -20 ~ (-30) KPA, and the coal depth is 1.5 ~ 2.5 m, the gas drainage effect is the best with the increase of the distance between the bottom of the borehole and the bottom of the borehole. The interaction between the boreholes is weakened. The drainage rate is taken as the criterion. It is suggested that the interval between the coal seam bottom and the coal seam in the DK474 138T of Baiyanglin Tunnel is 2 m, and the drainage period is 70 d. 4) the effect of explosion proof modification on the dynamic performance of construction machinery is obvious. The same type of modified machinery and non-refitted machinery are proposed. Under the same test conditions, for the transport machinery, when the speed is the same, the modification time is about twice as long as that of the non-refitted machinery, the acceleration performance is reduced, the average acceleration is reduced by 15 percent, the power is reduced by 15 percent, and for hydraulic machinery, The output power is reduced by 15 / 20 and the average moving speed of the arm is reduced by 33.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U455.4

【参考文献】