What is a type of caisson and cofferdam in construction?
A caisson is a waterproof structure used in underwater construction, typically made of reinforced concrete, which can be open or closed at the bottom. It is designed to hold back water and soil while allowing workers to excavate below the waterline. A cofferdam, on the other hand, is a temporary structure built to create a dry work environment for construction in or near water bodies, effectively isolating the area from surrounding water. Both are essential for foundation work in bridge and pier construction.