This is my assessment using hec ras

This is my assessment using hec ras


ENG515 - ASSIGNMENT 2 - USE OF HEC-RAS FOR ANALYSIS OF UNSTEADY FLOW - 1 OF 2 CHARLES DARWIN UNIVERSITY ENG515 WATER RESOURCES ENGINEERING ASSIGNMENT 2 - USE OF HEC-RAS FOR ANALYSIS OF UNSTEADY FLOW In these computer sessions, and with this assignment, you will have opportunities to use HEC-RAS to perform an unsteady flow analysis of a network of reaches containing junctions, bridges, culverts, and hydraulic connections. The geometric data for this study illustrate multiple unsteady flow applications in HEC-RAS. This work focuses on modelling and evaluating hydraulic connections, and hydraulic parameters in an unsteady flow environment. You should start by becoming familiar with modelling bridges, culverts, multiple reaches, and junctions. You will need to carry out the following analyses and write a brief report on your findings (see below). The data files are available in the 1-d unsteady flow examples of the HEC-RAS software (Multiple reaches with hydraulic structures/3ReachUnsteady.prj). You need to load this information into HEC-RAS at the start of your work and convert the project from US customary to SI units. Geometric data The geometric data consist of two channels (Fall River and Butte Creek) connected by a junction. Three structures are included: a culvert roadway, and two bridges. The culvert roadway is located at River Station 10.1 on the Fall River Upper Reach and bridges are located at River Station 0.22 on the Butte Creek Reach and River Station 9.55 on the Fall River Lower Reach. The following hydrographs (Fig. 1) have been selected as representative of the design conditions. These are already input in the example. Several issues have arisen with regard to development of the land around this drainage system and with modifications to the existing bridge at RS 9.55 on the Fall River Lower Reach. Figure 1 Hydrographs representing design conditions ENG515 - ASSIGNMENT 2 - USE OF HEC-RAS FOR ANALYSIS OF UNSTEADY FLOW - 2 OF 2 Tasks a. Become familiar with the system described by analysing the flow behaviour for the status quo. b. Examine the culvert roadway located at River Station 10.1 on the Fall River Upper Reach. It is feared that a blockage to its circular, and box, culverts may cause flooding problems. Find the implications of 2.4 m of blockage (almost 100%) to these culverts throughout the flood event described by the hydrographs above. c. The bridge at River Station 9.55 on the Fall River Lower Reach is to be modified and upgraded for improved strength as the structure was found to have cracks in its piers and erosion was present on the riverbank below the road deck. Create a new design that includes wider piers and abutments but does not increase the peak water surface at the bridge by more than 0.25 m during flood conditions. d. Tree planting will occur upstream: it is estimated that this may decrease the flow in both hydrographs (Fig. 1) by 1% per annum over a 30-year period, stabilising thereafter. Experiment by changing the hydrograph and/or other data to ascertain the likely implications of this reforestation over the 30-year period from planting to maturity. Submission of a brief report for this Assignment must be made via LearnLine in .pdf file format before the dead- line (1630 ACST, Wednesday Week 11). The length of the report is limited to 600 words ± 10% (excluding Appendices) and not more than six pages of A4. It should cover the outcomes of the investigations in Parts b), c), and d), above. It should be written to a professional standard, using past tense and, in general, passive voice. Students should retain an electronic copy of the HEC-RAS files they produced during this Assignment as a spot-check may be made to confirm the submitted results. The report may include a number of screen-shots by way of illustration. Marks will be deducted for mistakes in spelling and grammar. A word count must be included at the end of the report. The work you submit must be your own work - plagiarism will result in a zero mark for this Assignment.