This European Standard specifies the execution of diaphragm walls as both retaining and cut-off and the practical aspects which shall be taken into account in the production of the working drawings. NOTE 1 This standard covers only structures where soil is removed and replaced by concrete or slurry. NOTE 2 Diaphragm walls can be permanent or temporary structures. NOTE 3 The following types of structure are concerned: retaining walls: usually constructed to support the sides of an excavation in the ground. They include: cast in situ concrete diaphragm walls; precast concrete diaphragm walls; reinforced slurry walls; cut-off walls: usually constructed to prevent migration of groundwater, clear or polluted, or of other liquids present in the ground. They include: slurry walls (possibly with membranes or sheet piles); plastic concrete walls. NOTE 4 This standard is relevant only for excavated walls constructed in a trench. The trench may be excavated with a support fluid or in dry conditions. NOTE 5 Shallow vertical trenches (D/B < 5, the ratio of depth over thickness and D limited to 5 m) are not covered by this standard. NOTE 6 The design, planning and execution of diaphragm walls call for experience and knowledge in this specialized field. The execution phase requires skilled and qualified personnel and this document cannot replace the expertise of specialist contractor.