Analysis on the Advantage of Trenchless Construction's Cost by Disutility-Cost Assessment Method in China

Trenchless technology (TT) methods, including horizontal directional drilling, pipe jacking and pipe renewal are advanced methods for installing, repairing and renovating of underground pipes, ducts, cables, etc., with minimum excavation of ground surface. In China, the number of small-scale projects using horizontal directional drilling (HDD) equipment has increased quickly, while the number of large-scale project by pipe-jacking is increased slowly, and there are only a few projects using pipe replacement (renewal). One of the important obstacles in growth of trenchless technology is the difficulty in estimating the cost of trenchless construction, including the cost to general public, environmental impacts, damage to pavement and underground existing utilities and structures, when compared to the open-cut methods. This paper puts forward a disutility-cost assessing method combined with linear regression method. Firstly, the total disutility of trenchless construction can objectively be estimated by quantitative analysis on the factors related to trenchless construction. Then, on the basis of the assessment we derive a model to calculate the cost and obtain the characteristic parameters and empirical constant of the cost model by means of linear regression method. Finally, the cost advantage of trenchless construction will be worked out by comparing with other construction methods of underground utilities. This paper is helpful for engineers to make a rational decision among underground utility construction methods.