水平定向钻施工穿越膨胀土渠堤环境影响安全监测

Environmental Impact Safety Monitoring of Horizontal Directional Drilling Construction across Expansive Soil Canal Embankment

水平定向钻施工是一种铺设地下设施(管道、电缆等)的新型技术,其免开挖地面、低成本、高效率、环保、污染少等技术优势在生产中逐步显现。定向钻水平穿越膨胀土通水渠堤,目前中国尚无工程先例和既定规范可循。通过对某天然气管道水平定向钻穿越工程敏感性分析,以及针对性开展环境影响安全监测,掌握了定向钻施工穿越对渠堤的影响范围、渠堤的变形规律等,分析、验证提出了“定向钻施工期间,渠堤沉降值不大”、“定向钻孔腔内泥浆压力差是影响膨胀土渠堤安全的关键因素”等重要结论,并将监测成果运用于过程监控和施工指导,以此优化、确定质量管理和控制措施,收到较好效果,为膨胀土渠堤安全管理和维护、后续制订穿越渠堤相关规范,以及其它水利水电工程定向钻施工穿越,提供了参考。

Horizontal directional drilling construction is a new technology for laying underground facilities(pipes,cables,etc.),and its technical advantages such as no excavation of ground,low cost,high efficiency,environment-friendly and less pollution gradually appear during construction.Directional drilling that horizontally traverses the expansive soil to canal embankment currently has no engineering precedent and established codes to follow in China.Based on the sensitivity analysis of a horizontal directional drilling traversing project of a natural gas pipeline and the targeted environmental impact safety monitoring,the impact scope of directional drilling construction crossing on the canal embankment and the deformation law of the canal embankment have been obtained.Important conclusions such as"during the drilling construction,the settlement of the canal embankment is not large"and"the mud pressure difference in the directional borehole cavity is a key factor affecting the safety of the expansive soil canal embankment"are analyzed and verified.The monitoring results are used for process monitoring and construction guidance to optimize and determine quality management and control measures which have yield good results and provide a reference for the safety management and maintenance of expansive soil canal embankment,subsequent formulation of relevant specifications for traversing canal embankment,and directional drilling traversing construction for other water conservancy and hydropower projects.