Abstract:
Preliminary cost estimates rely on the conceptual design of
the project and use only basic design technologies. Although
they present the lowest expected accuracy, they are often used
by key people involved in the construction process, thus playing
a significant role. Bridge construction has increased over the last
years, often exhibiting substantial overruns above estimated costs.
To overcome this problem, it is crucial for the decision makers to have
an early estimate of the final cost based on previous experience. This
paper addresses the need for easy-to-use and reliable cost estimates
during the early stages of projects for bridge superstructures,
presenting a major impact on the total bridge construction cost.
It proposes a conceptual cost estimate method that involves the
estimation of both the material quantities and the relevant costs.
It describes the development of prediction models for the material
quantities of concrete and reinforcing and prestressing steel for three
major bridge deck construction methods using regression analysis,
while a bootstrap resampling method is used to produce estimate
ranges. The material estimating models rely on the development of a
database after collecting actual data from a large sample of modern
bridges. The major assumptions underlying the correct application of
the regression methodology were tested, and necessary adjustments
were made. The proposed conceptual cost-estimating methodology
uses information known before detailed plans are developed to
provide fast and reliable results that can be very useful in the early
stages of a road project.
Keywords:
Construction costs; Bridges;
Estimation; Regression
analysis; Bootstrap
|
| 
