Nailed walls based on reinforced concrete sprayed dry
The nailed wall is the technical solution “go everywhere” to realize a large part of the supports, they are on existing retaining walls or to realize for example in cuttings during the creation of real estate projects.
This technical solution, although heavy and expensive, allows a level of guarantee of durability of the retaining structure which can be high and can be dimensioned up to 100 years if necessary. A nailed wall can thus advantageously replace (cost, lead time) a Berlin micro, but can also find alternative solutions of substitutions in some cases and geological context in other retaining techniques such as HLE nets / HR grids for example.
General principle of realization of a nailed wall
- Earthworks in cuttings in a tread or in passes (or no prior earthworks)
- Creation of boreholes for the introduction of sealed metal reinforcement type GEWI or self-drilling technique
- Realization of reinforcement (single or double layers of welded mesh)
- Realization of a seat of the book (Armed Beton peach, BA sill on micropiles, …)
- Dry-spray concreting according to the number of passes required to obtain the desired final thickness.
We can find other less common applications of nailed walls to create (need to build terraces on steep slopes) or recreate areas of lost land (during landslides). In this case, the founded nailed wall is built on lost formwork (wood, aluminum, …) deported to position the future retaining wall at the desired location and then backfill the area and thus benefit from a new platform. The anchors previously made allow the support and the fixing of the formwork which will receive themselves then, the reinforcement and concrete projected.
This technique is practiced more rarely, it requires a great knowledge and experience to achieve the expected results on the aesthetic and technical level.
Hanging anchored sail
The nailed wall can also be declined according to a variant called “suspended anchored veil” which resumes the principle of the nailed wall but without foundation of seat, the work in the form of “patch” is thus self carried on these anchors. This principle allowing, for example, sometimes advantageously to curb a particular erosion zone and thrusts in the middle of existing grids work being undermined.