Grundfos PS.R.05 Montage- Und Betriebsanleitung Seite 8

4.2.1 Backfill
Do not use plate compactors at a distance of less
than 30 cm from the pit wall.
1 1a
Fig. 3 Compactors
• The backfill must provide sufficient support of the pit on all
sides and ensure that the load can be transferred without
detrimental point impacts or similar impacts. See fig. 4.
2
Fig. 4 Even pressure on all sides of the pit
• The backfill must meet the same requirements as those for the
bedding layer.
• The backfilling must be carried out so that the pit is not
damaged or deformed.
During backfilling, the cover must be fitted on the pit
to ensure that the pit is not deformed (becomes
oval).
Fig. 5 Oval pit after compaction
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• The backfill must be compacted in layers of maximum 30 cm
(corresponding to approx. 20 cm after compaction).
Max.
25 kN
Max.
150 kg
Fig. 6
Compact the backfill under the inlet and outlet pipes
properly so that they are not exposed to downward
loads when the backfill settles. See fig. 6.
Insufficient compaction under pipes
If the hole for the pit is drilled, pay special attention to
the compaction of the backfill to prevent uplift.
Use mechanical compacting equipment and compact
the backfill to minimum 97 % proctor density.