*How Do We Build a Bridge Column in the Middle of the Sea?

Imagine a massive, stable bridge stretching across the sea, and you wonder, "How was this column planted in the seabed? The sea is deep, the currents are strong, and the soil is unstable!"

What I'm about to explain is not fiction—it’s marine civil engineering, requiring a high level of intelligence and precision.

1. **The Beginning: Marine Survey**
Before any work begins, we conduct a thorough study of the depths, soil type, currents, tides, and earthquake risks. The goal is to understand where and how to proceed with construction.

2. **Deep Foundations: We Work from the Bottom Up**
There are two main types of deep foundations:

- **Piles:**
We use massive equipment to drive iron or concrete piles into the seabed until we reach a solid, supportive layer.

- **Caissons:**
These are large concrete boxes placed in the sea. Some are designed to sink to the bottom, while others are anchored to piles.

3. **We Dry the Sea! (Cofferdams)**
To create a dry working environment, we build steel barriers around the column site and pump out the water, allowing us to operate on temporary “dry land.”

4. **Pouring Concrete Underwater (Tremie Method)**
If preventing water intrusion isn’t feasible, we use special pipes to pour concrete directly under the water without affecting its flow.

5. **Corrosion and Salinity Resistance**
All materials must be treated to resist saltwater. Steel is covered with protective layers, and the concrete is specifically formulated for marine environments.

6. **Each Column = A Project on Its Own**
Each column is a significant investment, costing millions, and undergoes thorough testing and analysis to ensure it can support the weight of the bridge, vehicles, and withstand weather conditions for many years.

**The Result?**
Bridges like the King Salman Bridge or the Akashi Bridge in Japan stand tall on columns submerged in the sea, constructed with micron-scale precision and supported by advanced engineering.