Interface - Analysis and Design

MPADD2 uses the assumption of uniform flow to calculate the spread at a given curbed section. In accordance with the recommendations in HEC-12, the program uses a default value of 0.3% for the profile grade when the input data results in a grade of 0.3% or flatter. This approximation provides a reasonable solution for the design of most pavement inlets since:

For bridges on flat slopes, the MPADD2 program uses the special flat bridge design algorithm presented in the HEC-21 Hydraulic Engineering Circular on Bridge Deck Drainage. Therefore to extend the ability of the program to include the flat bridge case, two methodologies are presented to the user:

There are three modes for running the program: the batch design mode, the review mode, and the interactive one-by-one design mode. The mode of the program operation is selected by the user in the project input form. For batch design mode and review mode, the program will read the input data and send the results to the output page on the form. For the interactive one-by-one design mode, the program in the mode will ask the user for an inlet location and indicate the results at that location. The program will not proceed to the next inlet until the user approves the location and type of inlet at the station under consideration. This process is repeated until user has confirmed the completion of the design. The results are then either sent to the output page and can be saved as an input file for future use. During the design process, user can change the input data on the input form and get the result from these data. When the desired result is obtained, user can save the input data into the file and print the results.