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Subsoil improvement

Gronau
Site preparation for three residential buildings

Gronau, Germany / 2022

Radke Wohnbau GmbH is constructing three residential buildings in Gronau, in the Münster region. To ensure a secure foundation for the floor slab, PORR Spezialtiefbau manufactured approximately 160 load-bearing vibrated stone columns measuring up to 8m in length. This project was completed on schedule and to the complete satisfaction of the employer. PORR Spezialtiefbau Planung GmbH was responsible for planning.

Picture shows two specialised civil engineering machines facing each other.
© PORR

Facts & Figures


Company

PORR Spezialtiefbau GmbH

Type

Subsoil improvement, Planning

Runtime

2022

Principal
Radke Wohnbau GmbH

Vibratory compaction columns for load transfer

Around 160 load-bearing vibro-compaction columns were constructed for the foundations. The columns are up to 8 m long and serve to transfer loads into the subsoil. This method is used in particular on soils prone to settlement. By compacting the soil and installing columns of gravel or crushed stone, the properties of the subsoil are adapted for subsequent development. The vibro-compaction columns form the basis for the subsequent foundation and structural works.

Subsoil improvement

When constructing the vibro-compaction columns, a vibro-compactor is driven down to the specified depth. The column is then built up step by step from the bottom upwards. The coarse-grained fill material is introduced using compressed air and compacted into the subsoil by repeatedly raising and lowering the vibratory rammer. In this way, the individual columns are formed within the subsoil. The subsoil improvement was tailored to the geological conditions of the site as well as to the requirements of the planned buildings.

Preparation for the structural works

The works were carried out before the actual structural construction phase began. Once the ground improvement was complete, the foundations and floor slabs of the three residential buildings could be constructed. Step by step, the foundations for the future residential development on the site were thus laid.

Foundation for new residential buildings

Even before the flats, façades and Outdoor facilities are built, the loads of the future buildings are transferred into the subsoil via the vibro-compacted columns. The installation of around 160 vibro-compacted columns laid the groundwork for the subsequent construction phases. In Gronau, this is thus creating the foundation for new residential space in the Münsterland region.