The bridge builders laid a stone foundation under the water and threw many stones along the longitudinal line of the bridge to build an underwater stone embankment more than 20 meters wide and 1 kilometer long. A single stone is easily washed away by the sea tide, but after forming a stone foundation, it is not easily washed away by the sea tide.
But how do these stone foundations solidify into a whole? Bridge builders thought of a "biological construction method". They cleverly used biological materials to solve the solidification problem of submarine bridge piers. It turns out that craftsmen have long discovered that there are many shellfish growing in the ocean. They have two shells, one shell can be closed freely, and the other shell is bonded to rocks or other shells. They secrete a sticky substance that sticks one side of their shell to the rock. Once fixed, it will no longer separate. They use this to anchor themselves and prevent them from being swept away by the tide. This is a means for them to adapt to the environment and survive. Shellfish grow and reproduce rapidly. After continuous accumulation, they will form dense and solid "shell cement" around the bridge foundation and bridge piers, which not only tightly combines the bridge piers and bridge foundations, but also solidifies the bridge foundation on the seabed. into a whole. Based on this biological principle, bridge builders stocked oysters around the bridge base, allowing them to grow, reproduce, and secrete adhesive to secure the bridge piers. This very scientific method of building bridges is still very remarkable even today.