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Sealing slabs


If a waterproof construction pit, also known as a trough construction pit, does not have a horizontal, water-retaining soil layer, it is necessary to create a largely horizontal sealing floor slab to close off the pit.    

We offer the following methods for producing sealing slabs:

  • Deep jet-grouted sealing slabs
  • Soft gel injection slabs
  • Mid-height jet-grouted sealing slabs
  • Underwater concrete floor slabs

Deep jet-grouted sealing slabs

The jet grouting method involves introducing a waterproofing slab of cement into the soil below the base of the excavation pit. Jet-grouted sealing slabs can be installed deep in the ground so as to allow the soil above the slab to prevent buoyancy uplift. The construction pit enclosure must be implemented at a corresponding depth.

Soft gel injection slabs

We produce soft gel injection slabs economically, with a high level of technical safety and an impressively low CO2 footprint. We have three general type approvals from the German Institute for Building Technology (Deutsches Institut für Bautechnik, DIBt) for our soft gels. Soft gel bases are produced at low depths, as the gel-like, watertight structure does not harden completely.

Mid-height jet-grouted sealing slabs

Mid-height jet-grouted slabs are an alternative possibility. They can be anchored back against buoyancy uplift with grouted micropiles, for example. The micropiles also can be extended upwards to secure the subsequent floor slab against uplift.

Underwater concrete floor slabs

Underwater concrete floor slabs are constructed as heavyweight slabs (d = 1.5m – 2.0m) and placed higher up. Alternatively, they can also be back anchored with reduced thickness.

Planning expertise for safe and economic implementation

Our skilled engineers are on hand to provide you with comprehensive advice right from the planning stage. We develop the technically and economically optimum solution for your construction scheme on the basis of your specifications.

  • Consulting + planning in specialist civil engineering

Individual design

We always carry out base sealing slab assignments in line with the individual building task at hand.  The choice of the best method depends to a large extent on the prevailing geological conditions such as stratification of the subsoil or groundwater levels, the existing spatial conditions on site and the planning constraints. Where necessary, we secure the sealing slab against uplift with grouted micropiles.

Integrated solutions for complex requirements

In addition to carrying out individual tasks for construction pit enclosures, we also offer construction pits as an integrated, all-in-one solution. As a general contractor, we handle complex construction projects and coordinate tasks that go beyond the scope of specialist civil engineering. This includes all aspects of construction pit work.

The best result for every geotechnical challenge

Benefit from our decades of expertise in specialist civil engineering and problem solving skills – especially when it comes to challenging construction tasks. As a responsible general contractor, we are an experienced advisor able to provide you with expert support, even in the event of unexpected problems, and ensure successful completion of your project.  We have the entire range of specialist foundation engineering methods at our disposal.

Customer benefits

  • In-house technical staff
  • In-house specialist equipment
  • All methods from a single source
  • Planning with a 3D model

Selected reference projects

Injection grouting
New waterworks Dörenthe . Ibbenbüren
Injection grouting
Quartier Hoch 4 . Mannheim
Jet grouting
Sewer rehabilitation Emscherallee . Dortmund
Jet grouting
Palais an den Ministergärten . Berlin