Builder: FHH Autobahnmeisterei Stillhorn

Location: Stillhorn

Mountain formation: Loose formations

Drilling method: Annulus resealing lance pressing

Number of holes: 1

Drilling depth in m: 29.5

Total drilling meters: 29.5

Drilling Ø in mm: unknown

Expansion data: DN 150 / 200 / PVC

Purpose of the drilling:

According to UWB Hamburg, a sealing of the annular space from 6.50 m below GOK to the bottom of the shaft was required for this bridge.
The aim of this measure should be the hydraulic seal between the storage and seepage water horizon and the used aquifer.

This extinguishing water well was resealed using injection lances. In this case three lances were flushed in. The actual pressing process took place via double packers from the lance, through the perforations arranged at intervals of approx. 0.3 m and covered with rubber bandages. As a grouting compound, a clay powder-cement suspension was pressed into the annular space in a ratio of 70/30 clay/cement with a grouting pressure of 5.0 bar. The success of the measure was checked geophysically using CAL / IL / GG.D / NN / and SGL.