🌊

Chapter 04 of 5

Subterranean Giants

Explore the massive concrete feats holding back oceans and taming wild rivers.

1. The Weight

   Gravity’s Anchor

   Gravity dams use sheer concrete mass to resist the horizontal pressure of water. Without millions of tons of weight, the river would simply push the wall aside.

2. Marine Chemistry

   Saltwater Survival

   Seawater corrodes standard concrete. Modern underwater structures use 'pozzolans' like fly ash to make the mixture dense enough to keep salt out.

3. Deep Roots

   The Caisson Method

   Engineers sink giant hollow concrete boxes called caissons to the seabed. They pump the water out to create a dry workspace for foundation building.