Development of Cost Functions for Open-Cut and Jacking Methods for Sanitary Sewer System Construction in Central Taiwan

This study developed cost functions applicable to open-cut and jacking methods, which are construction techniques of sewer systems often used in gravel strata. The cost functions obtained by linear regression, expressed as functions of pipe size and excavation depth, were used to estimate the construction costs of sewer systems. Data for several real sewer system construction projects in Taiwan were investigated to verify the accuracy of the cost functions. Analytical results revealed that estimated and real costs deviated by less than 5%, a difference less than that for cost functions currently utilized in Taiwan. The cost functions developed in this study are more realistic, practical, accurate, and easy to use than existing functions. As the Taiwanese government is now implementing the building operator transfer policies for sewer system construction, the proposed cost function should prove to be a very useful tool, allowing both government and contractors to quickly estimate sewer construction budgets.