Assignment from Werner & Partner AG: two boreholes with
a diameter of 200 mm, drilled to a depth of 18 m into the Emme gravel, in the middle of a residential area. Space was extremely limited: a building on the left, trees on the right, utility pipes in the ground, and access routes that had to be kept clear.
Burgdorf, CH
Werner & Partner AG
Studersond AG
2 pieces | Ø 200 mm
18 m
Emme gravel
4.5" piezometer tubes, pumping tests
Limited space
Drilling in water-bearing, sandy gravel poses special challenges for borehole stability. Continuous casing secured the borehole in the Emme gravel deposits throughout its entire depth. Uncontrolled collapse, which could endanger the filter and seal sections during excavation, was ruled out from the outset. This created the conditions for a clean, accurate installation of the 4.5-inch piezometer pipes and for pumping tests whose results can be clearly attributed to the sampled horizon.
The subsequent pumping tests provided the basis for a reliable assessment of groundwater yield—a reliable assessment because the pumping parameters could be clearly defined.
The compact design of the TL18geo and its low ground pressure of 0.6 kg/cm² made it possible to position the machine in a sensitive residential area. This prevented damage to the pavement, tree roots, or the surrounding area.
