Do you know how the piers of the sea crossing bridge are made?

Do you know how the piers of the sea-crossing bridge are made?

Do you know how the piers under the sea-crossing bridge were built?The piers looked difficult to build, but they weren't complicated at all, and the engineers used the cofferdam method.

Before construction begins, a soil detector is used to check whether the subsoil can withstand the loads of the permanent structure. First, a temporary dam needs to be built, a guide pile is set at a predetermined location to support the construction of the cofferdam, and then a locked sheet pile is inserted into the bottom, which minimizes water leakage.

After the cofferdam is built, the water inside is drained with a pump, and you will find that as the water level drops, there will be leaks between the plates. Therefore, we need to build a double-layer cofferdam and pour concrete in the middle of the two layers of cofferdam to prevent water leakage.

Although there is no water leakage, because the water in the cofferdam is drained, it is easy to make the entire cofferdam collapse inward under the action of the internal and external water pressure difference, because the external seawater pressure is greater than the cofferdam, resulting in an inward force. Engineers used a support frame structure to solve this problem. A ring of transverse steel structural supports is installed inside the cofferdam to resist inward movement.

Now that the underwater works are halfway completed, the next step is to stabilize the foundation. An excavator is used to remove all the silt inside the cofferdam and then poured with concrete so that it is tightly connected to the rock formation. After the concrete is processed, the next step of construction work begins. Due to the long-term immersion of the piers in seawater, the quality of the reinforcement materials used must be the best, otherwise the consequences are unimaginable.

Finally, concrete is poured in a rebar skeleton model. Once the concrete has fully set, the previously inserted sheet piles can be cut, so that solid piers can be built, ready to support heavy bridges at any time.