NBN EN 1538+A1:2015

This European Standard establishes general principles for the execution of diaphragm walls as either retaining walls or cut-off walls.
NOTE 1 This 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 2 Diaphragm walls can be permanent or temporary structures.
NOTE 3 The 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 4 Walls 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.