This European Standard establishes general principles for the execution of diaphragm walls as either retaining walls or cut-off walls.

NOTE 1This standard covers only structures constructed in a trench excavated with a support fluid or in dry conditions, where soil is removed and replaced by concrete or slurry and with wall thickness B ≥ 40 cm.

NOTE 2Diaphragm walls can be permanent or temporary structures.

NOTE 3The following types of structure are considered:

a)retaining walls: usually constructed to support the sides of an excavation in the ground. They include:

1)cast in situ concrete diaphragm walls;

2)precast concrete diaphragm walls;

3)reinforced slurry walls;

b)cut-off walls: usually constructed to prevent migration of groundwater, clear or polluted, or of other contaminants present in the ground. They include:

1)slurry walls (possibly with membranes or sheet piles);

2)plastic concrete walls.

NOTE 4Walls formed shallow vertical trenches (typically excavations with a ratio of depth over thickness D/B < 5 or D < 5 m) are not covered by this standard.