ABSTRACT
The aim of this paper is to point out the advantage of Cost Benefit Analysis (CBA) and its economic indicators to assess a rehabilitation of bridges. The paper includes short example of assessment of the project economic efficiency in which economic indicators are applied in order to evaluate of two technology project variants of bridge object rehabilitation. It quantifies and compares the economic results of alternative 1 with the monolithic prestress construction and alternative 2, with the composite steel–concrete bridge. The contribution reflects the current practice of economic analysis recommended by the Ministry of Transport, Construction and Regional Development.
Economic evaluation is always based on a technical solution. Acquisition costs essentially reflect the cost of the technical complexity of the project and, in addition, in civil engineering also construction site conditions. The technical solution is also reflected in social benefits of the project.
Before considering the economic efficiency of the before mentioned two variants of the RBO project, it is briefly presented the reasons for rehabilitation, which are: very bad or breakdown state condition of the existing bridge object supported by extensive diagnostics, dynamic and static load test of the bridge. The present bridge structure performs services over the railway, resort of ČOV and river Kysuca. The project deals with the reconstruction of the bridge. The technical solution is designed in two variants; the variant 1 is characterized as a monolithic construction of prestressed concrete and variant 2 is characterized as a composite steel-concrete construction. The length of upperbridge is 263,400 m, length of the bridge is 306.590 meters, the bridge span fields: 30.0 + 5 x 41.0 + 30.0 m, height of the bridge max. 11.92 m (in the field no. 6), the bridge area: 3,911.55 m2. Alternative 1 is a cheaper to compare with alternative 2. At the same time, the alternative 1.
A comprehensive assessment of the economic efficiency of bridges rehabilitation projects, as it was already stated, is only possible by applying various methods of economic CBA indicators. Cost-benefit analysis of the project can be carried out as an economic (if the project realization will never serve public purposes) or financial (if the building generates revenues). In our case it is a project that will generate revenue, so we use economic analysis and the following economic indicators:
Economic Payback Period
Economic Net Present Value
Economic Internal Rate of Return
Economic Benefit-Cost Ratio
