A concrete footbridge 3m wide and 1.8m deep spans L= 16 m across a valley as shown in Figure P4a. The live load on the footbridge has a value of q= 5.0 kN/m2. The footbridge also acts as a culvert to channel water through the two holes along its length, each of diameter d = 1.3 m as shown in the figure. During heavy rain the holes completely fill with flowing water. Assume: Density of concrete = 24 kN/m ; Density of water = 9.8 kN/m3 ; Gravity g = 9.8 m/s2. + Live load = q kN/m2 3m + 1.8m Holes of diameter Lm d m to transfer water Figure P4a. Footbridge (not to scale) i) Calculate the self-weight of the concrete structure, in units of kN/m, in the direction of the bridge span. Provide your answer to at least 2 decimal places Concrete bridge self-weight [KN/m] = i) Calculate the maximum weight of the water that can be carried by the bridge at the one time. Provide your answer in units of kN/m to at least 2 decimal places. [1 mark] Weight of water transported [KN/m] =iii) Calculate live load acting on the bridge in units of kN/m, in the direction of the bridge span. Provide your answer to at least to 2 decimal places. [1 mark] iv) Based on the loading in parts a) to c) what is the ultimate limit state (ULS) loading that you would design the bridge to carry? Provide your answer in units of kNlm to at least 2 decimal places. [0.5 mark] v) Based on the loading in parts a) to c) what is the serviceability limit state (SLS) loading that you would design the bridge to carry? Provide your answer in units of kN/m to at least 2 decimal places. [0.5 mark] vi) When the water ow exceeds the bridge capacity the bridge is shut to trafc using gates at either end of the bridge. A typical gate 3m long and H = 0.6m high is shown in Figure P4b. It is made of solid rod members that individually weigh 5 kg/m. Calculate the weight of a gate in kNlm along its 3m length, assuming this load to act as a uniformly distributed load on the bridge. Provide your answer to at least 3 decimal places. [1 mark] ! 3.0 m II __ Typical spacing between vertical members = 0.15m Figure P4b: Gate side elevation