A team of transport engineers have addressed safety concerns at a railway crossing on an existing...

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A team of transport engineers have addressed safety concerns at a railway crossing on an existing level highway (Grade = 0) by proposing the construction of a highway overpass (above the existing railway line). The following design constraints have been imposed: • The existing highway has a design speed of 80km/hr • Symmetrical vertical curves are designed for the overpass, the sag curves must be designed with a rate of vertical curvature of 30 (Ks = 30) while the crest curves must be designed with a rate of vertical curvature of 26 (Kc = 26). •The road surface of the overpass structure must be 8m above the existing highway. • The overpass structure (bridge) must be level (Grade = 0), centred above the railway line and the length of the level bridge must be 100 metres. Please answer the following questions. a) Draw a clear labelled diagram presenting the overpass design described above. Clearly indicate the railway line, the vertical curve components, the bridge and indicate the dimension constraints described above. b) Calculate the minimum length of the existing highway that must be reconstructed to provide the appropriate vertical alignment. A team of transport engineers have addressed safety concerns at a railway crossing on an existing level highway (Grade = 0) by proposing the construction of a highway overpass (above the existing railway line). The following design constraints have been imposed: • The existing highway has a design speed of 80km/hr • Symmetrical vertical curves are designed for the overpass, the sag curves must be designed with a rate of vertical curvature of 30 (Ks = 30) while the crest curves must be designed with a rate of vertical curvature of 26 (Kc = 26). •The road surface of the overpass structure must be 8m above the existing highway. • The overpass structure (bridge) must be level (Grade = 0), centred above the railway line and the length of the level bridge must be 100 metres. Please answer the following questions. a) Draw a clear labelled diagram presenting the overpass design described above. Clearly indicate the railway line, the vertical curve components, the bridge and indicate the dimension constraints described above. b) Calculate the minimum length of the existing highway that must be reconstructed to provide the appropriate vertical alignment.

Answer rating: 100% (QA)

a Here is a clearly labelled diagram of the overpass d... View the full answer