New bridge helps straighten Bolivia Hill

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An artist's impression of the new bridge, straightening the highway's pass over Bolivia Hill. (Photo: Roads and Maritime Services.)

An artist's impression of the new bridge, straightening the highway's pass over Bolivia Hill. (Photo: Roads and Maritime Services.)

According to RMS, the highway realignment over Bolivia Hill contains the following features:

  • 1635 metres long.
  • The rock face next to the two metre shoulder in the southbound lane is softened by casting a concrete barrier against the rock face
  • The first 210 metres consist of a simple widening of the existing carriageway to the west by constructing a fill embankment.
  • The next 265 metres will require a retaining wall of up to three metres high to keep the fill embankment out of the creek line.
  • As the alignment diverges from the existing carriageway over the next 75 metres, the road will be widened by a cantilevered concrete structure on concrete piles.
  • This structure leads into a major bridge up to 360 metres long.
  • At the northern abutment of the bridge, a 60 metre long cantilevered concrete structure on concrete piles is again used to ease the alignment back towards the existing carriageway.
  • The next 110 metres widen out the existing carriageway, requiring a retaining wall of up to two metres high on the western side.
  • The next substandard bend is straightened out by gently moving off the existing alignment to the west and then re-joining the existing carriageway 145 metres further along .
  • Bend straightening requires the next 150 metres to move to the east of the existing carriageway by cutting into the rock face. Fill then tapers back 255m to the existing highway.
Diagrammatic cross-section of the proposed new road bridge. (Illustration: Roads and Maritime Services.)

Diagrammatic cross-section of the proposed new road bridge. (Illustration: Roads and Maritime Services.)