Akashi Kaikyō Bridge

 

The world's longest suspension bridge and designed to withstand powerful typhoon, tsunami, and earthquake.

1.Material 2.Suspension Bridge 3.Stronger Chains 4.Building Underwater
5. Taller Towers 6.Wind

The conventional bridge was the stone arch since Roman time, but 30 meters is about the
limit of this type of bridge can struggle.

To make the stone arch wider, it must also be made higher to preserve semi-circular shape
provided its strength. So the stone arch would be larger and collapse on its won weight.

The structure of the iron bridge looks like the wooden joint.

Pre-fabricate.

Beneath the bridge deck hanging the gantry allowing the maintenance workers to inspect
without interrupting the traffic.

There is no solid rock to secure the anchor, so they must build the anchor point on the shore.
First, they dug the gargantuan hole for the foundation.

Filled with the concrete.

The mammoth metal frame will anchor the bridge cables and must be firmly secured.

They set the metal frame in the concrete and cast the concrete into five blocks, the gaps 

between the blocks allowed heat to dissipate, so the concrete doesn't crack.

 

 

As we can see the water had been pumped out.

 

Using the caisson to form the foundation. The caisson made up of steel rather than wood.

The tugboats tugged the caisson to the location.

Each caisson has the inner and outer wall, the gap between the walls forms the circular 

compartments filled with the air. This keep the caisson buoyant.

To sink the caisson, engineers fraught the compartments with the seawater.

Once the caisson located on the seabed, they filled with the concrete.

Because they are hollow, rather than the solid stone, and the steel allowed the tower to flip

instead of  the buckle under the stress of the cables.

 

 

The internal honeycomb structure  makes them lighter and strong. 

 

As the bridge deck gets longer, they are more likely to twist and bend. Wind.

Tacoma Narrows Bridge

As the wind flows through the bridge deck creating eddy.

Make the streamed shape is one of the solutions.

Girder

The lattice steel allows the wind to flow unimpeded through the structure.

Verrazano-Narrows Bridge

Double Deck

The wind test suggested that the bridge deck needed to deflect the wind as well as against it.

So they installed the massive beam below the roadway, as the strong cross wind hit the beam

Damper to counteract the vibration. Singapore Sky Wheel, Taipei 101, Dubai Hotel Truss

Workers simulate the earthquake.