METHOD AND DEVICE FOR CORRECTING THE POSITION OF A SLAB CONSTRUCTION CONSISTING OF PRECAST CONCRETE SLABS

PROCEDE ET DISPOSITIF POUR CORRIGER LA POSITION D'UN CONSTRUCTION REALISEE A PARTIR DE PLAQUES PREFABRIQUEES EN BETON

English Abstract

The invention relates to a method for correcting the position of a slab
construction, especially a solid carriageway for high-speed vehicles,
consisting of precast concrete slabs (1). The precast slabs (1) are supported
by a substructure made from a hardenable underpoured material (4) and a
supporting layer (5) on the base. In order to correct the position of at least
one precast slab (1), the precast slab (1) is at least partially detached from
the substructure, especially from the under poured material (4) and/or the
supporting layer (5), whereupon it is finely aligned and then underpoured once
more with said material (4). A separating device (20,21) is arranged on a
precast concrete slab (1) which is to be detached on a successive precast
concrete slab in a device provided with one such separating device in order to
detach at least one part of a concrete slab (1) pertaining to a solid
carriageway for high speed vehicles from the substructure thereof, especially
when the position is corrected.

French Abstract

L'invention concerne un procédé pour corriger la position d'un construction réalisée à partir de plaques préfabriquées en béton (1), notamment d'une voie de circulation fixe pour moyens de transport à grande vitesse. Selon l'invention, ces plaques préfabriquées (1) sont supportées par une infrastructure constituée d'une masse (4) durcissable, coulée sous l'infrastructure, et d'une couche (5) servant de support pour l'infrastructure. Pour corriger la position d'au moins une plaque préfabriquée (1), on détache au moins partiellement cette dernière de l'infrastructure, notamment de la masse coulée (4) et/ou de la couche de support (5), puis on la rectifie avec précision, avant de procéder de nouveau au coulage d'une couche (4) sous ladite plaque. L'invention concerne également un dispositif comportant une unité de séparation servant à détacher au moins une partie d'une plaque préfabriquée (1) placée dans une voie de circulation fixe destinée à des moyens de transport à grande vitesse, guidés sur rails, notamment pour procéder à une correction de position. Cette unité de séparation (20, 21) est placée sur la plaque préfabriquée (1) à détacher ou sur une plaque succédant à cette dernière.

Claims

1
Method and Device for Correcting the Position of a
Slab Construction Consisting of Precast Concrete Slabs
Claims
Claimed is:
1. A method for the positional correction of a slab construction of precast
concrete slabs (1), especially
for an existing carriageway for high speed vehicles, wherein the precast
concrete slabs (1) possess
spindles (7) and said slab construction is carried by an underconstruction of
a hard curing undergrout
(4) and a carrier layer (5) of an under base, therein characterized,
in that, for the said positional correction of least one precast concrete slab
(1), the said precast
concrete slab (1) is at least partially separated from the understructure, in
particular from the
undergrout (4) and/or from the carrier layer (5) and
in that during the separation the spindles (7) are removed from the site of
the separating cut and
in that after the separation, the spindles (7) are returned to support
location and the precast concrete
slab (1) is finely aligned by said spindles (7) and
in that the precast concrete slab (1) is provided with a renewed pour of an
undergrout (4).
2. A method in accord with Claim 1, therein characterized in that, the under
support, particularly the
undergrout (4), is at least partially separated.
3. A method in accord with one of the foregoing Claims, therein characterized,
in that the understructure,
particularly the undergrout (4), is separated in the longitudinal direction or
in the horizontal direction
from the precast concrete slab (1).
4. A method in accord with one of the foregoing Claims, therein characterized,
in that
undergrout (4) is essentially separated at or in proximity to the contacting
surface of the precast
concrete slab (1) and/or the carrying layer (5).
5. A method in accord with one of the foregoing Claims, therein characterized,
in that the understructure,
in particular the undergrout (4), is separated over the complete breadth of
the precast concrete slab (1).
6. A method in accord with one of the foregoing Claims, therein characterized,
in that before the
separation of the understructure, in particular, the undergrout (4), an
opening is made in the
understructure, in particular the undergrout (4) for the insertion of a
separating means, in particular a
saw blade.

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"SLAB POSITION CORRECTION ... "
7. A method in accord with one of the foregoing Claims, therein characterized,
in that the separation line
exhibits a length, which is unequal to the length of a precast concrete slab
(1), and especially is not on
the contact location where two precast concrete slabs (1) abut.
8 A method in accord with one of the foregoing Claims, therein characterized,
in that on the precast
concrete slab (1), filling openings (9) are opened or created and employed for
the renewed under-
pouring.
9. A method in accord with one of the foregoing Claims, therein characterized,
in that
closed filling openings of the old undergrout (4), are opened and made use of
for renewed under
pouring.
10. A method in accord with one of the foregoing Claims, therein
characterized, in that the precast
concrete slab (1) is exactly aligned by especially mechanical or hydraulic
lifting means, such as
spindles or lifting cushions, these means being placed inside and/or outside
the precast concrete slab
(1).
11. A method in accord with one of the foregoing Claims, therein
characterized, in that the precast
concrete slab (1) is undergrouted with an especially rapid-cure bitumen cement
mortar, a plastic, or a
cement mortar.
12. A method in accord with one of the foregoing Claims, therein
characterized, in that the understructure,
especially the undergrout (4) is separated by a saw, in particular a cable saw
(20), a chain saw, or blade
saw.
13. A method in accord with one of the foregoing Claims, therein
characterized, in that the understructure,
especially the undergrout (4) is separated by an oxygen lance.
14. A method in accord with one of the foregoing Claims, therein
characterized, in that the understructure,
especially the undergrout (4) is separated by a high pressure water stream.
15. A method in accord with one of the foregoing Claims, therein
characterized, in that the cut opening in
the understructure is cleaned before the renewed pour of grout.
16. A method in accord with one of the foregoing Claims, therein
characterized, in that for the more rapid
binding of the undergrout (4), the pour location is heated.

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"SLAB POSITION CORRECTION..."
17. A method in accord with one of the foregoing Claims, therein
characterized, in that a complete precast
concrete slab (1) can be removed from the slab construction and replaced by an
exchange slab.
18. A device with a separation apparatus for the release of at least one part
of a precast concrete slab (1) of
an existing carriageway for rail guided, high speed, vehicles from its
understructure, especially in the
case of a positional correction in accord with one of the foregoing Claims,
therein characterized, in that
the separating apparatus (20, 21) is placed on the precast concrete slab (1)
which is to be loosened or
on an adjacent following precast concrete slab (1).
19. A device with a separating apparatus for the loosening from its
understructure of at least a part of a
precast concrete slab (1) of an existing carriageway for rail guided high
speed vehicles, especially in
the case of a positional correction in accord with the foregoing Claims,
therein characterized, in that
the separation device (20, 21) is placed on a guide structure independent of
the precast concrete slab
(1) to be loosened, in particular on an adjoining track.
20. A device in accord with the foregoing Claim, therein characterized, that
the separating device (20, 21)
cuts through the understructure, especially the undergrout layer placed
beneath the precast concrete
slab (1).
21. A device in accord with one of the foregoing Claims, therein
characterized, in that the precast concrete
slabs (1) are bound together.
22. A device in accord with one of the foregoing Claims, therein
characterized, in that the separating
apparatus (20) is placed on the rails (2) of a first or second precast
concrete slab (1).
23. A device in accord with one of the foregoing Claims, therein
characterized, in that the separating
apparatus (20) is part of an assembly (20, 21) and within the said assembly
(20, 21) exercises a thrust
in a longitudinal direction of the precast concrete slab (1).
24. A device in accord with one of the foregoing Claims, therein characterized
in that the separation
apparatus (20) and/or the assemble (20, 21) is guided on the rails (2).
25. A device in accord with one of the foregoing claims, therein
characterized, in that the
assembly (20, 21) is placed securely on the rails (2), in particular, is
clamped thereon.
***

Description

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Method and Device for Correcting the Position of a
Slab Construction Consisting of Precast Concrete Slabs
Description
The present invention concerns a method and a device for the positional
correction of
slab construction of precast concrete slabs, especially the slabs of a solid
carriageway for
high speed vehicles, whereby the precast concrete slabs are underset with a
hard curing
grout and are supported by a carrying layer of base fill.
Known concrete slab construction projects with precast concrete slabs are,
among
other applications, employed for existing carnageways for high speed traffic
vehicles.
The high speed vehicles are, in this present application, guided by rails. In
order to
achieve operation which is free of disturbance and comfortable on a high speed
carriageway, it is necessary that the rails, and therewith the slabs of the
slab construction
be laid very exactly in regard to elevation and lateral dimensioning. The
positional
correction of the rails is done, normally, by means of known rail fastening
systems as
well as by means of interposing shims of different thicknesses underneath the
rails. In
this way, positional faults of the rail of the magnitude of about 30 mm can be
compensated for. The disadvantage of this is, that greater corrections, which
are
frequently necessary when a subsidence of the base fill occurs, cannot be
adjusted with
such corrective measures, since such settling requires greater corrective
movements.
Thus the purpose of the present invention is, to make possible a positional
correction
of a slab construction of precast concrete slabs, which permits a greater
elevation
correction.
This purpose is achieved by the features of the Claim 1 as well as the
features of
Claim 17.
In the method of the invention, a slab construction of precast concrete,
especially of
an existing carnageway for high speed vehicles, is corrected on site. The slab
construction possesses two precast slabs bound to each other, wherein the
precast slabs
are set into a hard curing grout and are supported on a carrying layer base
fill. For the

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positional correction of at least one precast slab, or a portion thereof, the
said precast slab
is entirely or partially released from its grout setting, and/or from its
carrying layer, and is
subsequently exactly realigned, and then the cut is refilled anew with
undergrout. This
method can well account for large corrections in elevation. The loosing, or
releasing, can
be carried out either by chemical or by mechanical means. The most
advantageous
method depends on the surrounding conditions and the materials of the grout.
If the substructure, especially the undergrout and/or the carrying layer, is
cut through
longitudinally and/or transversely, then in a very simple manner, the
loosening of the
precast slab can be carned out. The decision, as to whether the understructure
should be
cut in a longitudinal or a transverse direction, is dependent upon the kind of
subsidence
the slab has suffered, the correction tools which are available, and the
conditions of the
working environment.
If the grout material is cut through at (or near) the contact area of the
precast plate,
and/or the if it is the carrying layer which is cut through, then assurance
can be made, that
a satisfactory grout entry and strong binding of the new grout to the precast
concrete slab
will be made.
If, before the cutting of the understructure takes place, particularly that of
the grout, a
boring is made in the said understructure for the insertion of the cutting
means, that being
especially a saw blade, then it is not necessary to cut through the precast
slab at the
beginning of the separating cut of the understructure.
If the line of the cut shows a length, which is unequal to the length of the
precast slab,
and especially if said line does not begin or end at the contact point of two
precast slabs,
a possible weakness at the slab contact point is thereby avoided.
If, in the precast slab, grout feed openings are opened or created and used
for fresh
grout, then the filling of the new understructure grout is substantially
eased. A filling of
the grout which is essentially free of air inclusions is thus enabled.
It is especially of advantage, if, closed up openings for the old undergrout
are opened
and made use of for the new substrate grout.
If the precast slab can be exactly aligned with integrally placed mechanical
or
hydraulic lifting means already within said slab, for instance, spindles, then
it often

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becomes possible, in a simple way, that these means, still available from the
first
alignment can aid in the present alignment of the precast slab.
In order to avoid damage to the spindles by cutting through the layer, it is
of
advantage, if the spindles are removed from the area of the separation before
the through-
out and only replaced in their support position after the cut.
In order to restore travel operation as soon as possible on the precast
concrete slab, it
is of advantage, if the precast concrete slab is underlain with an especially
fast-cure
bitumen-cement mortar, plastic or cement mortar.
A device in accord with the invention exhibits a separation apparatus for the
loosening, and especially for the through cutting of an understructure,
particularly the
grout, placed beneath a precast slab of a carnageway for track guided high
speed
vehicles.
The existing carriageway consists mainly of at least one set of a first and a
second precast
concrete slab bound together. The cutting device is placed on the precast slab
to be
loosened, or on an adjacently placed precast slab, or advantageously, on the
rails.
A further invented apparatus possesses a separating device for the loosing of
at least a
part of a precast slab of an existing carnageway for rail guided high speed
vehicles from
its understructure. The separating device is on a guidance mechanism
independent of the
precast slab to be loosened, and is particularly well placed on the next rail.
The existing
carriageways are mostly laid in double-track manner, so that the separating
device can be
run on the next rail for the loosening of the required rail.
If the cutting device employs a self moving power in the longitudinal
direction of the
precast concrete slab, then, by a fixed placement of an abutment for the
cutting device, a
relatively long track stretch can be cut.
Advantageously, the separating device and/or the assembly are guided on the
rails. In
this way, an exactly guided cut is possible.
If the cutting assembly is firmly affixed on the rails, in particular, clamped
thereon,
then a fast equipment relocation for the lengthening of the separation cut is
possible.
Further advantages of the invention are described in the following embodiment
examples. There is shown in:
Fig. 1 a plan view of a precast concrete slab,

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Fig. 2 a cross-section through the construction of a placement of a precast
concrete slab,
Fig. 3 a section through the undergrout,
Fig. 4 a view of the lifting of the precast concrete slab,
Fig. 5 the filling of the space between the lifted precast concrete slab and
the
carrier layer, and
Fig. 6 an embodiment example of a cable saw.
In Fig. 1 is presented a top view of a precast concrete slab 1. The precast
concrete
slab 1 possesses a multiplicity of projections, upon which the rails 2 are
fastened. The
rail fastenings, which can be executed in numerous known ways, permit a
certain
adjustment of the said rails in the vertical and horizontal directions.
Insofar these
adjustment possibilities do not suffice, for instance, because of the
subsidence of the
substructure, it becomes necessary to upwardly adjust the precast concrete
slab 1 itself .
For this purpose, in the present embodiment, at six positions are placed
spindles 7, which
serve for the adjustment of the slab 1. The spindles 7, which are provided on
the ends of
the slab 1 as well as in the middle thereof, by a more or less difficult
turning of the
spindles 7 a fine adjustment of the slab 1 is achieved. These spindles 7,
which normally
are already installed at the setting of the slab 1, obtain, by means of the
present invention,
a second purpose, namely, in that they enable the correction of the already
set slab. The
spindles are aligned as matching, oppositely situated pairs.
Fig. 2 presents a cross-section through a construction of the precast concrete
slab 1 as
well as showing the successive strata. The precast concrete slab 1,
surmounting an
intermediate layer of undergrout 4 is to be found on a carrier layer 5. The
carrier layer 5
can be, for example, hydraulically bound or possibly an asphalt or another
appropriate
supporting layer. The grout 4 binds the precast concrete slab 1 tightly to the
Garner layer
5. A spindle 7, which served for the alignment of the precast concrete slab 1
at the first
setting of the same, is presented in a drawn down position, because it does
not perform
any load bearing function for the precast concrete slab 1. The said spindle is
placed in a
recess in the undergrout, so that it will be of service in the future.

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For the correction of the precast concrete slab l, in accord with Fig. 3, the
undergrout
layer 4 is shown as cut. By this means, the precast concrete slab 1, after the
undergrout 4
has been cut, is now vertically movable, within the framework of its
connections in the
slab construction. It is of exceptional value, if the cut in the undergrout 4
is made
directly at the dividing plane to the precast concrete slab 1. By this means,
a higher
quality binding of the new filling of undergrout, which is yet to be poured,
with the
precast concrete slab 1 is assured. The old connection layer of the undergrout
4 with the
precast concrete slab 1 is, by this operation, relieved of its previous
carrying function and
is bound to the new layer. Advantageously, it is also possible to make the
separating cut
between the Garner layer 5 and the undergrout 4. Even in this case, a possibly
loose
connection can be renewed. The separation at or in proximity to the connection
location
between the precast concrete slab 1 and the undergrout is, in any case, easier
to carry out,
since, when the known thickness of the precast concrete slab 1 is at hand,
this location is
more simply determined by means of an instrument and accordingly can be more
exactly
cut. Although the thickness of the undergrout 4 can vary, this connection
location is
simpler to capture than that of the connection plane of the hydraulically
bound carrier
layer 5.
If the precast concrete slab 1 must be lowered, then a square cross-sectional
block of
the undergrout is cut out and subsequently the precast concrete slab 1 is
allowed to drop
into the opening thereby formed.
In Fig. 4, the lifting of the precast concrete slab 1 is shown. By the driving
down of
the spindle 7, and the corresponding fine alignment of the precast concrete
slab 1, the
said slab is raised away from the under support structure. The opening is, by
this action,
made larger.
In Fig. 5, the precast concrete slab 1 is newly under filled with grout. The
undergrout
is now in the cured state, so that the spindle can again be relieved of the
load.
In Fig. 6 is shown in sketch form, the arrangement of the separating device on
the
precast concrete slab 1. The separating device, which can be a cable saw, an
oxygen
lance, or other means, can be carried on a movable slider 21. The slider 21 is
drawn by
means of a cable winch over the location at which the precast concrete slab 1
is to be cut.
The winch, that is the cable, is anchored at a fixed abutment. Advantageously,
this

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abutment can be placed on the adjacent precast concrete slab 1. As a guide for
the said
slider 21, this function can be fulfilled by setting the slider 21 on the
rails which
surmount the precast concrete slab 1. Likewise, the rails 21 can serve for the
fastening of
the said abutment. The abutment, in this case, is advantageously clamped to
the rails 21
and after the maximum travel of the slider 21 has been expended, then the
abutment itself
can be moved ahead fox a renewal of the separating cut.
For a quicker cure of the new undergrout, especially in cold weather, it is
advantageous if the undergrout or the separation opening is heated. In order
to achieve a
satisfactory connection to the new undergrout, in any case, it is of advantage
if the
opening is cleaned before the refill with a high pressure water stream. The
separation
opening can also extend into the carrier layer, if the new grout material is
chosen to be
compatible with the said carrier layer to make a good bonding.
The present invention can also be employed for the replacement of complete
precast
concrete slabs. The original slabs, in this case, are completely removed from
the
interconnected binding system and replaced by exchange slabs.

Representative Drawing