A diaphragm wall (slurry wall) is a reinforced cast-in-place continuous concrete wall. The construction includes the excavation of a trench under the protection of a support suspension (i.e. a thixotropic slurry such as bentonite mud for example) designed to temporarily stabilize the trench wall. After excavation with a mechanical or hydraulic grab, the support slurry is replaced by concrete and steel reinforcement is placed.
Construction sequence
Installation process in accordance with the requirements of NBN EN1538:1999
1. In advance construction of temporary guide walls and excavation of (the first) lamella with grab – continuous filling of the trench with the thixotropic stabilizing fluid.
Excavation of the first rectangular panel, followed by the excavation of the second one (alternating method).
Construction sequence
Installation process in accordance with the requirements of NBN EN1538:1999
1. In advance construction of temporary guide walls and excavation of (the first) lamella with grab – continuous filling of the trench with the thixotropic stabilizing fluid.
Excavation of the first rectangular panel, followed by the excavation of the second one (alternating method).
In order to avoid instability of the trench, the level of the bentonite slurry in the excavation trench should at any moment be maintained at least 2 m above the highest water level in the full height trench, especially in the case of an artesian aquifer.
2. Panel excavation in progress: excavation of the central panel or “merlon” located between the two previously excavated panels.