Cofferdam is a temporary structure that helps to carry out the construction work under reasonable dry conditions. Now, what is the sandbag? A sandbag is nothing but a bag filled with sand and clay. When these sandbags are used to make a cofferdam, it is known as a sandbag cofferdam.
In this system, at first, empty bags or empty cement bags are collected as required. Then they are partially filled with a mixture of clay and sand. Next, partially filled bags are laid in courses just like masonry work and at last empty space between bags is filled with puddles to make them water-tight.
It has been observed that sandbag cofferdam can withstand the swift of water currents successfully. The side slope of this cofferdam is very steep as sandbags can even maintain the verticle face.