Feasibility Study for Hydraulic Modeling Facility for Scour Problems (1408-1F)

The feasibility of building a large scale scour modeling facility to help evaluate the 26,018 bridges over water which exist in Texas is studied. First, the scour problem in Texas is reviewed and tends to indicate that many bridges are built on clay. Second, the fundamental laws of hydraulic and soil modeling are detailed. These laws show that it is not possible to scale all the components of the problem properly. It is also shown that when the model soil has particles smaller than 0.1 mm, additional difficulties occur. This makes the physical modeling of clays nearly impossible. Third, five bridge case histories are used to calculate the necessary size of scaled models. Scales of 1/15 to 1/100 would be used in the proposed facility. Fourth the results of a paper survey and visits of prominent scour modeling laboratories in the USA are presented. They show that these laboratories are relatively well equipped. Fifth, the new facility is designed and cost is estimated at $6.7 M. Finally, the advantages and disadvantages of building a new facility versus using existing facilities are outlined.