Productivity analysis of horizontal directional drilling

With the rapid increase of new installations, replacement and repairs of pipe utilities, the demand for trenchless excavation methods with minimum disruption to the public such as horizontal directional drilling (HDD) has increased. Canadian National Research Council reports that rehabilitation of municipal water systems would cost $28 billion from year 1997 to 2012 (NRC 2004). Contractors, engineers, and decision makers are always facing a challenge of how to estimate the cost of new pipe installation using the HDD due to the presence of subjective factors. The HDD process involves a large number of factors to be considered for productivity prediction and cost estimation. Therefore, an emergent need for developing a dedicated HDD productivity model is currently undertaken to meet industrial needs. The presented research aims at identifying the main factors that affect productivity of HDD operations and designing a productivity model. A neurofuzzy approach is utilized to design the HDD productivity prediction model for underground pipe installations in clay soil. The neurofuzzy system is developed based on actual project data that are collected through interviews, phone calls and questionnaire surveys. Results show that crew and operator skills and pipe diameter greatly affect the HDD productivity and the project as a whole.