Stabilizing the ground – 21 m high.

Technically speaking, it’s quite simple: Heap up masses of soil, compact, and you’ve created an artificial plateau in a flash. Practically speaking, an earthmoving project is likely to assume very different dimensions, however, when the terrain covers an area totalling 160,000 m² with a difference in level of up to 21 m. Some 200,000 cubic metres of soil had to be moved in the German village of Windhagen.

Soil stabilization for an assembly plant in Windhagen, Germany

Soil stabilization for an assembly plant in Windhagen, Germany

The client was none other than Wirtgen GmbH: Their main plant – situated in the industrial estate of Hambitze – had reached its capacity limits, and an expansion had been decided on. The new building covers a floor space of 20,000 m² and is 11 m high. The artificial plateau was necessary to ensure that the old and new parts of the company premises would be on one and the same level. Vögele pavers built access roads to the job site in a first work step to enable trucks to deliver the huge masses of soil.

Two Wirtgen soil stabilizers, one WR 2500 and one WR 2500 S, stabilized the soil at a working depth of 50 cm by mixing in a pre-spread mixture of lime and cement in accordance with the soil’s moisture content. 10 to 30 kg of binding agent per square metre were required to produce a subbase of good bearing capacity. Two single-drum compactors of the 3000 series from Hamm, one equipped with a smooth drum, the other with a padfoot drum, then compacted the previously stabilized soil.

The compactor fitted with padfoot drum, a 3520 P with an operating weight of 20 tons, came first, rolling the ground four times in each direction. It was followed by the second compactor, which was fitted with a smooth drum to produce a compact, water-repellent surface seal. The machines worked their way upwards layer by layer until the plateau had reached its final height. The most exciting question then was as to whether the surface had been compacted to a uniform density. Laboratory samples, plate bearing tests, and the use of the HCQ GPS Navigator – a system for continuous compaction control from Hamm – all confirmed that an average density of 97% had been achieved. Construction of the new assembly plant could begin.

Job site: Windhagen, Germany
Total area: 160,000 m²
Difference in height to be levelled: 14 to 21 m
Mass of soil moved: 200,000 m³
Binding agents added: 2,500 tons each of lime and cement