QUESTION 1: 30 MARKS There has been significant rain in Southeast Australia over the past few months. This has many chal

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Question 1 30 Marks There Has Been Significant Rain In Southeast Australia Over The Past Few Months This Has Many Chal 1 (288.2 KiB) Viewed 33 times

QUESTION 1: 30 MARKS There has been significant rain in Southeast Australia over the past few months. This has many challenges on our large-scale dams. As a dam engineer, consider the following scenario in which you must keep the dam operational during a rainfall-runoff event. The dam is W = 80 m wide and Hdam = 100 m tall and the reservoir can be assumed to be w = 80 m wide and L = 1 km long. The dam and reservoir can be assumed to have VERTICAL walls. The reservoir can be assumed to be a rectangular feature. The dam includes a scour valve to release water but this is assumed closed until Part 1B of this Question. Refer to Figure 1 for details. L= 1 km Hwater Hdam = 100m W = 80 m F Scour valve h_scour o a) Aerial View looking back at the dam wall b) Side View Figure 1. Images showing (a) dam and reservoir from the air, (b) side view of the dam wall (not to scale). QUESTION 1A: FOR THIS PART OF THE QUESTION, ASSUME THE SCOUR VALVE IS CLOSED. Complete the following: a) If the dam can withstand a maximum horizontal force (F= 3.54 x 106 kN), what is the maximum height of water (Hwater) that you can allow the dam to have? Provide your answer in meters to 2 decimal places. (5 MARKS] b) Draw and clearly label the pressure distribution of the water on the dam wall. [2 MARKS]
c) If the origin (0) is assumed to be at the bottom corner of the dam wall (see Figure 1), how high above this point is the pressure force acting? Provide your answer in meters to 2 decimal places. Provide a sketch for clarity. [4 MARKS] d) Assuming now that the initial height of water (Hwater) at the start of the rainfall- runoff event (time, t=0) is 60 m. If the inflow rate into the reservoir is estimated to be continuously Qin = 5000 L/s, how long will it be until the reservoir water level (Hwater) is 80 m? Provide your answer in hrs to 2 decimal places. [8 MARKS] QUESTION 1B: FOR THIS PART OF THE QUESTION, ASSUME THE SCOUR VALVE IS OPEN. When the height of the water (Hwater) inside the reservoir reaches 90 m, you now decide to open the scour valve. The centre of the scour valve is located (h_scour = 10 m) above the bottom (i.e., above the origin, 0). The valve is a circular pipe with diameter d = 1 m. See Figure 1. e) Calculate the exit velocity from the scour valve right when it is opened (i.e., with Hwater = 90 m.) Provide your answer in m/s to 2 decimal places. You can assume no head losses for this question. [5 MARKS] f) Draw a suitable streamline to use to solve this problem. Label your diagram. [2 MARKS] g) List 2 assumptions we consider in the Bernoulli equation [2 MARKS] h) In real fluids (like what you cover in Part 2 of this course) list 2 other considerations you would need to include in your calculation of the exit velocity from part e. [2 MARKS]