Risk Evaluation for Maxi Horizontal Directional Drilling Crossing Projects

Horizontal directional drilling (HDD) has become increasingly used for the construction of large diameter (more than 600 mm or 24 in.) pipeline projects throughout China. Due to the large investment of capital and resources, it is important to conduct a risk evaluation prior to actual construction. However, there are relatively few appropriate analyses or investigations available for such applications. This paper addresses the risk assessment for Maxi HDD projects. The combination of the fuzzy comprehensive evaluation method and analytical hierarchy process was adopted as the basic model. The corresponding risk indices were constructed considering the factors affecting the projects and based on discussions with experts who have conducted HDD crossing projects. Structured judgment matrices and membership matrices were then directly developed from the index systems, and the weight vectors, subordinated vectors, and risk values determined by the use of Matlab software. Finally, the risk level of the projects was obtained by implementing the maximum membership degree law. The synthesis of the fuzzy comprehensive evaluation method and analytical hierarchy process has been demonstrated to provide a theoretical basis for the risk evaluation and establishment of risk control measures for Maxi HDD projects.