1 Trenchless Installations Preserve Pavement Integrity

Horizontal directional drilling (HDD) has been successfully used to perform trenchless pipeline installations under highways, roads, waterways, and various other situations where traditional open cut-and-cover methods will results in significant traffic disruptions and/or environmental damage. In the case of pavements, utility and pipeline cuts have been shown to accelerate pavement deterioration and create significant user delays. Initially trenchless pipeline construction bids were higher than open cut-and-cover methods. However, if full life cycle costing methods are used trenchless construction methods are more cost-effective than the low bid open cut. This is the first known study that investigates the comparative impacts of directional drilled and conventional open cut and cover pipeline installations on pavement integrity and performance. Obtaining such comparisons under the same levels of subgrade type, pavement structure, traffic, and environmental conditions is unique and will provide field data that will be important to both the trenchless and pavement industries