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 substrate made from hardenable underpoured material ( 4 ) and a supporting layer ( 5 ) on the base. In order to correct the person 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.

Description:
DESCRIPTION  
         [0001]    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.  
           [0002]    Known concrete slab construction projects with precast concrete slabs are, among other applications, employed for existing carriageways 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.  
           [0003]    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.  
           [0004]    This purpose is achieved by the features of the Claim 1 as well as the features of Claim 17.  
           [0005]    In the method of the invention, a slab construction of precast concrete, especially of an existing carriageway 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 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.  
           [0006]    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 carried 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.  
           [0007]    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.  
           [0008]    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.  
           [0009]    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.  
           [0010]    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.  
           [0011]    It is especially of advantage, if, closed up openings for the old undergrout are opened and made use of for the new substrate grout.  
           [0012]    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 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.  
           [0013]    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-cut and only replaced in their support position after the cut.  
           [0014]    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.  
           [0015]    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 carriageway for track guided high speed vehicles.  
           [0016]    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.  
           [0017]    A further invented apparatus possesses a separating device for the loosing of at least a part of a precast slab of an existing carriageway 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.  
           [0018]    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.  
           [0019]    Advantageously, the separating device and/or the assembly are guided on the rails. In this way, an exactly guided cut is possible.  
           [0020]    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. 
       
    
    
       [0021]    Further advantages of the invention are described in the following embodiment examples. There is shown in:  
         [0022]    [0022]FIG. 1 a plan view of a precast concrete slab,  
         [0023]    [0023]FIG. 2 a cross-section through the construction of a placement of a precast concrete slab,  
         [0024]    [0024]FIG. 3 a section through the undergrout,  
         [0025]    [0025]FIG. 4 a view of the lifting of the precast concrete slab,  
         [0026]    [0026]FIG. 5 the filling of the space between the lifted precast concrete slab and the carrier layer, and  
         [0027]    [0027]FIG. 6 an embodiment example of a cable saw. 
     
    
       [0028]    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.  
         [0029]    [0029]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 carrier 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.  
         [0030]    For the correction of the precast concrete slab  1 , 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 carrier 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 .  
         [0031]    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.  
         [0032]    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.  
         [0033]    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.  
         [0034]    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 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 for a renewal of the separating cut.  
         [0035]    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.  
         [0036]    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.