There are four major ancient bridges in China, the Marco Polo Bridge in Beijing, the Zhaozhou Bridge in Zhao County, Hebei, the Guangji Bridge in Chaozhou, and the Luoyang Bridge in Quanzhou. These four ancient bridges have a long history and have stood for thousands of years. They are great bridge masterpieces of the ancients. Among these four ancient bridges, one bridge is different from the other three. The other three bridges are all built on rivers, but only this bridge is built on the sea. Below the Zhaozhou Bridge is the Mi River, below the Marco Polo Bridge is the Yongding River, and below the Guangji Bridge is the Han River. The Quanzhou Luoyang Bridge is a cross-sea bridge that spans the estuary of the Luoyang River in Quanzhou.
The builder of Luoyang Bridge was Cai Xiang, a great calligrapher of the Song Dynasty. At that time, Cai Xiang was transferred here to serve as magistrate. Before he took office, local people had to take a boat to get to the other side. Due to its location at the mouth of the sea, it would take a long time for the people to get to the other side when the tide was high. In order to facilitate the local people, Cai Xiang gathered the wisdom of people and decided to build a bridge. In this way, the first cross-sea bridge in history came into being.
We all know that building a cross-sea bridge is not easy even now, let alone in ancient times. To this end, this bridge adopts a new bridge construction method. Along the center line of the bridge site, stones are laid in the river to build a stone embankment, and then the bridge piers are built on the stone embankment. The piers are all shaped like boats, with pointed ends to reduce the impact on the piers.
In order to consolidate the stone strips piled up under the water into one body and prevent them from being washed away by the flood, the craftsmen who built the bridge came up with an ingenious way. There is a mollusk with a shell on the seabed along the coast called an oyster. It has two shells, one shell attached to a rock or another oyster, intertwined with each other, and the other shell covering its own soft body. Oysters have a strong reproductive capacity and are pervasive. Once they are glued together with the stone, a large amount of calcium carbonate material is formed, which cannot be shoveled down even with a shovel. Craftsmen took advantage of this characteristic of oysters and planted oysters on the bridge base. The bridge base and piers are naturally cemented into a whole.