TRADITIONAL VS TRENCHLESS - A COST COMPARISON CONCEPT

This paper presents a concept for modelling the main components of social cost associated with trenched works, which was developed by researchers at Louisiana Tech University, USA. Initially, a conceptual flow chart was developed tracing the linkages in the key phases of a decision-making process. This enables engineering, design, and construction alternatives to be matched with a project's financial, developmental, environmental, and safety aspects, allowing the recommendation of the best solution for client, contractor, and society as a whole. The total cost of a project is defined as the sum of the direct bid cost, which is the traditional contract cost based on quantities and specifications, and the indirect societal costs, including the costs of: (1) lane closure and traffic management; (2) business loss; (3) fuel consumption; (4) higher pollution; and (5) increased accidents. Data for this purpose need to be collected from the following areas: (1) demographic/economic; (2) traffic/accident; (3) geotechnical/hydraulic; (4) inventory of existing corridor; and (5) trenchless technology methods. The results are outlined of applying the concept to the study of a 1.9 mile section of the Youree Drive 5-lane highway, Shreveport, LA, USA, which is frequently flooded due to inadequate storm drains.