Download Installation Manual - Rainwater Collection Systems

- Cover rows of tunnel with filter fabric and arrange it in such a way that the fabric can adapt
to the serrations when covered with soil. Avoid
overstretched fabric at cavities. (If using 16/32
gravel, the rows of tunnel are not required to be
covered directly.)
- Secure foot embankment with soil in order to fix
filter fabric.
.
Backfilling of tunnel elements from sides
The tunnel element is backfilled from both sides
and top with suitable backfilling material in uniform
layers of maximum 20 cm
Image 10: Covering with filter fabric
- The uniform compacting of backfilling layers is
done with light consolidating device. With increasing altitude heavy consolidating devices
may be used (see Chapter 4.4)
Covering the tunnel elements
The load bearing capacity for connected road superstructures is to be taken into account while
convering the tunnel elements.
Image 11: Backfilling filter fabric for fixing
- The backfilling material with mixed grading
curve is consolidated in layers above the tunnel
shoulder up till the required load bearing capacity is obtained.
- When using 16/32 mm gravel, it is backfilled up
to 10 cm above the tunnel shoulder backfilled
and is covered flat with a separate layer of filter
fabric. The filter fabric is beaten down from all
sides (at least 50 cm overlapping). It is further
backfilled and compacted in layers with nonbinding soil material till the required capacity of
45 kN/m² is attained.
Image 12: Compacting with a small compacting device between rows of tunnel
Superstructure for paved road surfaces
Finally, the superstructure is created for the road
surfaces as per plan specifications.
Image 13: Covering the tunnel elements
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