Diaphragm wall is a continuous reinforced concrete wall constructed in the ground to support major construction activities like the construction of dams, tunnel approaches, deep basements and enclosures. They act as a retaining wall, support for the underground structure, as a foundation or facilitate cut off provision in order to support deep excavation.

A diaphragm wall forms a rectangular section constructed in-situ under the soil. Hence, this is an underground concrete wall. These walls are constructed panel-by-panel each interlocked to ensure structural stability and water tightness.

The diaphragm walls can have a thickness ranging from 60cm to 150cm with a width of 2.0 to 3.5m. The diaphragm walls can be constructed up to a depth of 60m.