[0001] The invention relates to an anchor intended for fitting at the bottom edge of a sheeting
panel which has to be pressed by means of a steel insertion sheet into a ground trench
as part of a wall comprising sheeting panels interconnected by section connections,
which anchor is U-shaped.
[0002] Such an anchor is known from DE-A-3540270 (Figure 9).
[0003] For the isolation of polluted ground and groundwater and in the case of well drainage
it is known to make use of vertical screens formed in the ground, made of a bentonite-containing
mixture in which a liquid-tight panel wall of thick HDPE sheeting is provided in order
to increase the water impermeability. The flexible panels of these walls are, for
example, 2 to 3 metres wide and are interconnected by means of locking sections. The
insertion of the panels by means of the steel insertion sheet takes place in such
a way that the locks are placed under little or no load. At the bottom side the bentonite
sheeting screen must be connected to a watertight layer, for example a natural clay
or an injected synthetic layer. In order to anchor a panel after it has been pushed
into the ground trench, use is made of an anchor of the type mentioned in the preamble.
The known anchor is fixed to the bottom edge of a sheeting panel by means of a separate
strip and screws. Rib-shaped spacers which prevent the insertion sheet from sticking
to the sheeting panel are fitted between the insertion sheet and the sheeting panel.
Fixing of the anchor to a sheeting panel is time-consuming.
[0004] The object of the invention is to produce the connection between anchor and sheeting
panel considerably more quickly without there being any risk of wedging occurring
between insertion sheet and anchor as a result of which the sheeting panel would be
pulled up with the insertion sheet during the raising of said sheet after the insertion
of said sheeting panel and the locks between the panels could consequently spring
apart.
[0005] According to the invention the anchor is to this end characterized in that the top
piece of one of the legs of the U is bent in the direction of the other leg for the
formation of a separate accommodation chamber for a thickened part present at the
bottom edge of the sheeting panel, while a space exists between the free edge of the
inward bent leg part and the above-mentioned other leg for the purpose of allowing
through the bottom edge of the steel insertion sheet, and in that a number of recesses
are provided in the anchor section for the purpose of reducing the longitudinal rigidity
of the anchor.
[0006] The virtually vertical-running recesses in the vertical leg of the U of the anchor
section, which can lie against the insertion sheet during the insertion of the sheeting
panel, reduce the local rigidity of the anchor section. The correct wedging between
anchor section and insertion sheet can be achieved by providing the correct number
of such recesses over the length of the anchor section and/or adapting the length
and/or the breadth of said recesses, depending on the shape of anchor section and/or
bottom part of the insertion sheet, as a result of which the insertion sheet can be
removed from the anchor without too much force after the sheeting panel has been pressed
into the lowest position and, in addition, the sheeting panel with its locks is not
placed under unnecessary stress.
[0007] In order to be able to reduce the rigidity of the anchor even more in its lengthwise
direction, the recesses can continue into a part of the bottom of the U.
[0008] The breadth of the recesses preferably lies between 0.5 and 300 mm.
[0009] In order to centre a sheeting panel when it is being pressed into the ground and
thereby take the load off the locking connections between panels, projecting centring
wings can be fixed on the anchor on both sides.
[0010] The invention will now be explained in greater detail with reference to the figures.
[0011] Figure 1 shows a cross-section through the bottom part of an anchor according to
the invention with insertion sheet and sheeting panel.
[0012] Figure 2 shows a perspective view of the anchor.
[0013] The steel anchor 1 shown in the figures is in the shape of a U of which one of the
flanges is bent inwards at its top part for the purpose of forming a channel into
which the thickened bottom edge 2 of a sheeting panel 3 is pushed. This sheeting panel
is made of plastic, for example HDPE, and is connected in a manner which is known
per se by edge locking sections to a sheeting panel already placed in the trenches.
[0014] A steel insertion sheet for pressing the sheeting panel with anchor into a ground
trench 4 filled with bentonite mixture is indicated by 5 and projects with its bottom
edge into the anchor.
[0015] In order to centre the sheeting panel when it is being pressed into the ground trench,
centring wings 6 are fixed to the anchor 1, projecting on either side. These wings
end in an upward-sloping part, so that during the downward movement of the anchor
they cannot become jammed in the trench wall when they come into contact with said
wall.
[0016] The wings are welded to the bottom of the anchor section, but they can also be connected
to the anchor section at other places.
[0017] The wings 6 at both sides of the anchor section can also be fixed as a continuous
unit to the bottom side of the anchor section.
[0018] Vertical-running recesses 7 are provided in order to be able to adjust the local
wedging between anchor section 1 and the insertion sheet 5. These recesses are preferably
of a minimum breadth of 0.5 mm and a maximum breadth of 300 mm. They can continue
into the bottom of the U.
1. Anchor intended for fitting at the bottom edge of a sheeting panel which has to be
pressed by means of a steel insertion sheet into a ground trench as part of a wall
comprising sheeting panels interconnected by section connections, which anchor is
U-shaped, characterized in that the top piece of one of the legs of the U is bent
in the direction of the other leg for the formation of a separate accommodation chamber
for a thickened part present at the bottom edge of the sheeting panel, while a space
exists between the free edge of the inward bent leg part and the above-mentioned other
leg for the purpose of allowing through the bottom edge of the steel insertion sheet,
and in that a number of recesses are provided in the anchor section for the purpose
of reducing the longitudinal rigidity of an anchor.
2. Anchor according to Claim 1, characterized in that said recesses are provided in the
above-mentioned other leg and can continue into a part of the bottom of the U.
3. Anchor according to Claim 1 or 2, characterized in that the breadth of the recesses
measures between 0.5 and 300 mm.
4. Anchor according to any of the preceding claims, characterized in that centring wings
are fixed to the anchor, projecting on either side.
