Utilization of Trenchless Construction Methods in Mainland China to Sustain Urban Infrastructure

Traditional methods of underground utility installation and replacement generally employ conventional open cut methods. These trenching methods in most urbanized settings typically create road closures, traffic delays, unnecessary detours, loss of access to homes and business, unsightliness, noise, and general disruption. Faced with population growth and an aging underground utility system, China has looked to emerging technologies to assist in providing sustainable solutions to addressing this situation. Three trenchless construction methods that have currently been adopted in China are horizontal directional drilling (HDD), pipe bursting, and pipe ramming. HDD is a technique that enables the installation of conduits and pipelines with minimum need for open-cut surface excavation. Pipe bursting is an accepted method for trenchless pipe replacement where an existing sewer or utility pipeline is replaced with a totally new structural pipe of equal or greater inside diameter. Pipe ramming is an established technology that provides a cost efficient alternative for placing steel casings under roads, railroads, finished landscapes, and structures. This paper describes each of the three trenchless construction methods and discusses several applications for sustaining underground utility networks through case histories of successful projects in China.