水平定向钻穿越施工的失效可能性研究

水平定向钻穿越施工是管道穿越工程的一种主要施工形式，在施工中由于地质条件、设备使用和穿越工艺选择等原因使其存在风险，因此有必要对其失效可能性进行研究。建立了包含“人、机、料、法、环”五方面的水平定向钻施工失效可能性指标评价体系，对于特征影响因素，如扩径比、管土摩擦系数等，运用回拖过程的力学分析得出其分布规律，用模糊化的方法将底层指标分值转化为先验概率，再代入贝叶斯网络进行概率推理，最终确定其失效可能性。以某管道工程采取水平定向钻穿越河流为例，得出其失效可能性等级为“较高”，最后提出了相应的控制措施。运用贝叶斯网络研究水平定向钻穿越施工的失效可能性具有重要的工程应用价值和现实意义。

Study on failure possibility of crossing construction by horizontal directional drilling

The crossing construction by horizontal directional drilling is a main method of pipeline crossing engineering, and there exists risk in construction process due to the geological conditions, the use of equipment and the selection of crossing technology, so it is necessary to evaluate the failure possibility. The index evaluation system on failure possibility of crossing construction by horizontal directional drilling was established, including five aspects like man, machine, material, method and environment. The distribution rules of characteristic influencing factors, such as borehole-pipeline diameter ratio, friction coefficient of pipeline and soil, and so on, were obtained by mechanical analysis on back dragging process. The scores of bottom indexes were transformed into prior probability through a fuzzy method, and probabilistic reasoning of them was conducted in Bayesian network, so as to determine the failure possibility. Taking an pipeline engineering which adopted horizontal directional drilling for crossing river as example, the grade of failure possibility was figured out to be relatively high, and the relevant controlling measures were put forward. It has important engineering application value and practical significance for studying failure possibility of crossing construction by horizontal directional drilling through Bayesian network.