Road network damage
Our roads have been damaged in many different ways:
- Cracking and splitting
- A number of roads cracked or split from the forces of the earthquakes. Some of the worst cracks were large enough to be classified as urgent safety hazards.
- Collapsing from damage to underground infrastructure
- Water, wastewater, electricity and telecommunications are in conduits under the roads in many cases. When these were damaged, the road above them also collapsed.
- Humps and hollows
- Most Christchurch residents would have experienced travelling over bumps and dips caused by earthquake movement. Mounds and potholes have also been caused by underground pressure from liquefaction.
- People who saw the roads in wave formations during the quakes have an unforgettable image. In some cases, this movement left the road surface uneven or distorted but did not actually cause surface cracking.
- Surface damage
- Sometimes sections of the road surface were displaced or deformed by the movement, so that it's been left in a rough state.
- Kerb/channel damage
- Kerbs (gutters) and channels were also damaged by the severe movements.
- Many roads around riverbanks, coasts, Port Hills, and Lyttelton Harbour collapsed when the embankment or cliff subsided. In some of the areas badly affected by liquefaction, the subsurface was not strong enough to support the weight of the roadway, and those roads also collapsed.
- Rocks fell on some roads around the coastal heads and Banks Peninsula, causing serious damage to the surface.
- Retaining walls collapsing
- Some retaining walls collapsed onto roads. Some have not collapsed but require stabilising with temporary supports which sometimes encroach on the road surface, reducing the road's usable width.