MICROTUNNELING TECHNOLOGY FOR CONDUIT CONSTRUCTION

The need to replace deteriorating underground utility infrastructure and to expand utility services increases the need for conduit construction. Trenchless technologies provide promise for the installation of underground conduits without open excavation. These technologies have the potential of reducing environmental impacts, and have the added benefit of minimizing the handling, treatment, and/or disposal of contaminated soil. This paper introduces a trenchless method of conduit construction, namely, microtunneling, and discusses the economic, productivity, and safety issues associated with this technology. Key factors affecting the selection of the microtunneling technology for conduit construction are also explored. Since the introduction of microtunneling in the United States in 1984, contractors have realized the capabilities of microtunneling and have found that the productivity of microtunneling can equal or even surpass that of open-trench methods. Due to the limited amount of personnel entry into the conduit, and the remotely controlled operation of the equipment in microtunneling applications, safety risks are also minimized.