汶马高速公路千枚岩板岩隧道瓦斯溢出机理及预测研究

发布时间：2018-05-12 03:43

本文选题：非伴煤瓦斯隧道 + 瓦斯运移　；参考：《西南交通大学》2017年硕士论文

【摘要】：瓦斯灾害是隧道建设重大危害之一,本文以汶川至马尔康高速公路鹧鸪山隧道为主要研究对象,开展鹧鸪山隧道工程地质条件的调查、相关资料的分析,对隧道内瓦斯气体形成、溢出机理、瓦斯预测、监测防治等进行较全面研究。瓦斯产生在炭质千枚岩、板岩等烃源岩地层,赋存在倒转背斜核部的构造裂隙中,盖层为千枚岩、板岩,鹧鸪山隧道定性为非伴煤瓦斯隧道。针对隧道构造部位、围岩完整性等,瓦斯浓度有明显差异,即愈接近炭质千枚岩地层,瓦斯浓度愈高;构造活动愈强烈,岩体愈破碎,瓦斯浓度亦愈高。千枚岩地层中,瓦斯涌出源具有压力高、随机分布、较稳定的特点。非千枚岩地层瓦斯涌出主要以裂缝型游离瓦斯为主,特点是压力低,流量小,分布不均,涌出具有随机性。鹧鸪山隧道围岩中瓦斯主要以游离态形式存在,赋存空间和运移通道为节理裂隙和片理。应用数值模拟软件Fluent对瓦斯气体在隧道空间中稳态进行了模拟从而得出瓦斯各组分气体质量分数变化情况。工作面附近,进风一侧瓦斯浓度较低,回风一侧的瓦斯浓度相对较高,从产生的气体分布质量分数云图可以看出,在瓦斯生成点的气体质量分数最大,随着风速的流动瓦斯逐渐向隧道的出口流动,最后稳定分布,气体压力分布呈现明显的涡流状态。本文提出了千枚岩板岩隧道瓦斯初判条件:含炭质千枚岩,高地应力,埋深800米以上,倒转背斜倒转翼。根据这些条件预测,前方1000范围及出口段平导出现瓦斯隧道的可能性大,建议将通风排烟井改在隧道进口段。
[Abstract]:Gas disaster is one of the major hazards of tunnel construction. This paper takes the Wenchuan to Barkam expressway as the main research object, carries out the investigation of the geological conditions of the partridge mountain tunnel, analyses the related data, and makes a comprehensive study of gas gas formation, spillover mechanism, gas prediction and monitoring prevention and control in the tunnel. In the carbonaceous phyllite, slate and other hydrocarbon source rocks, there are structural fissures in the core of reverse anticline. The cover is phyllite, slate and zhegshan tunnel is a non associated coal gas tunnel. In view of the structural parts of the tunnel and the integrity of the surrounding rock, the gas concentration is obviously different, that is, the closer to the carbonaceous phyllite, the higher the gas concentration is, the higher the gas concentration and the tectonic activity. The more strong, the more fractured rock mass, the higher the gas concentration. In the phyllite strata, the gas emission source has high pressure, random distribution, and more stable characteristics. The gas emission from the non phyllite is mainly fractured free gas, characterized by low pressure, small flow, uneven distribution and random emission. The main gas in the surrounding rock of the Zungu mountain tunnel is the main gas. In the form of free state, the occurrence space and the migration channel are joint fissure and cleavage. The gas gas in the tunnel space is simulated by the numerical simulation software Fluent and the gas mass fraction of each component is changed. The gas concentration in the air side is relatively low and the gas concentration in the air back side is relative near the working face. From the mass fraction of gas distribution, the gas mass fraction can be seen that the gas mass fraction of the gas generating point is the largest. With the flow of gas flow to the tunnel exit, the gas pressure distribution shows a clear eddy state. In accordance with these conditions, it is predicted that the possibility of a gas tunnel in the 1000 range and the exit section in the exit section is great, and it is suggested to change the ventilation and exhaust wells in the tunnel entrance section.

【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】：U456.33

【参考文献】