Method for accurately placing an insert in concrete, apparatus for performing said method , and railway track obtained through the method

The invention relates to civil engineering, in particular the construction of railway tracks. Indeed, this process is particularly advantageous to insert in a concrete slab, saddles supporting railway rails. It is also applicable in all cases where sealed in concrete, in a given position, with a precision of the order of a millimeter, an insert which comprises at least one cavity to be filled with concrete so that the the insert is resistant to major efforts.

Known from EP 0117323 a process to establish with precision relative to a reference line, connecting bars between two concrete slabs to make a highway or runway. These bars are placed horizontally and perpendicular to the plane of the expansion joint. This method comprises:<ul><li>run a continuous concrete slab and smooth surface;</li><li>then, while the concrete is fresh, push each connecting rod in fresh concrete, vibrating the bar to liquefy concrete around the bar during its movement until it reaches a given position: vibration during moving provide precise location relative to a reference line;</li><li>then establish an expansion joint which cuts the continuous slab and separates it into two tiles which are connected by the connection bars.</li></ul>

Various methods are known for making a railway track. The most common ways are supported by sleepers laid on ballast. However you realize ways without ties to specific applications, especially for tram tracks in traffic areas. These channels must be embedded in the floor, and therefore require the said disbursement earthworks. It minimizes the depth of the disbursement, to cut costs and reduce inconvenience to local residents and users of road pavements. For this, sends paths, with a concrete slab in place of conventional sleepers. The rails rest on the concrete slab by means of metal pieces called stool and rubber soles. The stools are attached to the concrete slab, to transmit the forces exerted by the passage of a tramway on this path.

One known method for producing such a path is: <ul><li>join two rails by manually setting spacers templates, adjustable height by means of cylinders to define the gauge and their altitudes;</li><li>manually set at regular intervals in each rail saddles, between the templates; each seat comprising, on one side of the threaded studs for fixing the seat to a rail, and having on another face, anchoring devices adapted to be sealed in concrete;</li><li>adjust these templates to the working plan is the planned altitude and present the required gradients;</li><li>ask recyclable sideforms;</li><li>pouring concrete under the rails and the cuff, so that the anchoring devices stools are covered and embedded in the concrete slab, and that it has a flat surface just below the rails.</li></ul>

This process requires great care in order to obtain a precise positioning of the rails by the jigs, and it takes time for mounting spacers templates and for the introduction of concrete. It is costly in labor. Not being of an industrial nature, it leaves a large part in the initiative and the expertise of the staff.

The object of the invention is to provide a method for producing a railroad track, without crossings, at a lower cost that known method.

The object of the invention is a method to implement an insert accurately in concrete, said insert may comprise one or more cavities to be filled with concrete, comprising:<ul><li>prepare a concrete having a firm consistency;</li><li>implement this concrete, correct and smooth its surface while it is fresh, to give the surface a given position with a given tolerance;</li><li>then, while the concrete is fresh, moving the insert in the concrete, by vibrating the concrete around the insert during its movement, until it reaches a given position with a given tolerance;</li></ul><b>characterized</b> in that it further consists in confining the concrete during installation of the insert in the concrete, to force the concrete to fill each cavity of the insert.

The above method lets you use inserts with relatively deep cavities without the risk of poor filling. Consequently, it ensures a very resistant anchorage constraints. This property is particularly advantageous for inserts supporting railway rails.

The well characterized method further provides high accuracy thanks to the collaboration of the three following characteristics:<ul><li>The fact of vibrating the concrete helps liquefy the moment near the point of application of vibration, allowing easy insertion, a good coating of submerged parts of the insert, and de facto a good seal. It should be noted that the vibration may be applied through the insert or other device independent of the insert, and positioned in the concrete in the vicinity of the insert.</li><li>The fact that concrete is in place first, it is smoothed and polished so that its surface has a relatively precise position has the effect that pressing the insert at a nominal depth (such as device anchoring of the insert will not be too much or insufficiently covered by the concrete), the insert at a position which is very close to the desired position is placed. Just a small change of the depression to compensate a position error of the concrete surface. The smallness of this change allows a very precise fit.</li><li>The insert retains this position with this accuracy throughout the concrete setting time because it quickly finds, after stopping the vibrations, a firm consistency that prevents a displacement of the concrete or of the insert under the action of their weight.</li></ul>

When applied to the embodiment of a railway track having rails supported by saddles provided with anchoring devices which may be sealed in concrete, the method according to the invention is characterized in that it further comprises:<ul><li>put the concrete in the form of a slab having a smooth surface whose position is derived from the position intended for the track running surface;</li><li>then, while the concrete is fresh, push each seat in the concrete slab, by vibrating the concrete around the saddle until it reaches a given position with a given tolerance.</li></ul>

The method enables to significantly reduce the cost of making a track railway, since there is no step of attaching braces templates, and check its position before pouring concrete. The accuracy obtained on the position of each seat is sufficient to achieve the desired precision for the spacing between the two rails of a track, and the position of the running surface. In addition, the filing of a concrete slab before installing the rails, not after, allows a classic slip form machine that can pour a concrete slab with very little labor.

According to an embodiment of the preferred embodiment, the process according to the invention is characterized in that, to drive a saddle in a concrete slab, by vibrating the seat, until it reaches a given position, with a given tolerance, it consists in slaving the position of the seat to a predetermined position set point along three mutually orthogonal axes or an equivalent frame of reference.

The method enables to automate the insertion of the saddle, while providing excellent positional accuracy.

According to one embodiment of the preferred embodiment, the method according to the invention is characterized in that, for driving seat until it reaches a given position, with a given position, it consists:<ul><li>In a first step, to push the saddle with a first set speed, leaving some freedom in the saddle in a horizontal plane, and by vibrating the seat with a frequency and vibration amplitude suited to rapid sinking, until that it reaches a position close to the setpoint;</li><li>then, in a second step, positioning the saddle with a second fixed speed, lower than the first, by vibrating this saddle with a frequency and an amplitude of vibration suited to fine positioning, until it reaches a position corresponding to the setpoint.</li></ul>

The invention also has for object a device for implementing the method according to the invention.

Finally, the invention relates to a railroad track obtained by the process according to the invention.

The invention will be better understood and other details will become apparent from the following description of exemplary embodiments of the device for carrying out the method according to the invention; and with the figures accompanying this description:<ul><li>1 shows an example of saddle can be used to produce a railway track, without sleepers; </li><li>2 shows a sectional view of a railway track comprising this type of saddle, and their stools were inserted by applying the method according to the invention;</li><li>Figures 3 and 4 show respectively a top view and a side view, in section, of the main part of an example of embodiment of the device according to the invention; this example being an insertion device for inserting a saddle of this type in a concrete slab;</li><li>5 shows an overview of this embodiment;</li><li>Figures 6 to 9 show four successive stages of operation of this embodiment;</li><li>Figures 10, 11, and 12 show two front views and a top view of a mobile machine capable of simultaneously insert two stool for performing a railway track.</li></ul>

The method according to the invention can be used to insert any type of metal insert, or non-metallic, may be sealed in concrete. 1 shows an example of saddle rail to rail, can be inserted by applying the method according to the invention. This example saddle, referenced 1, comprises:<ul><li>a pressed sheet steel plate, 3;</li><li>and two pins each having a threaded rod, respectively referenced 2 and 4, for fixing a rail on the saddle by screws, and a sealing rod, referenced respectively 9 and 6, having a generally cylindrical shape extending threaded rod, and having asperities, for example circular, ensuring retention in the concrete once it has hardened.</li></ul>

The plate 3 has a generally rectangular, flat, horizontal, comprising: a vertical edge 11 around its periphery, four reinforcing ribs, and two projections 5 and 10 having slightly inclined vertical walls. These bosses 5 and 10 are designed especially to work with parts, not shown, to be used for subsequent attachment of a rail. In the use that is made here, the protrusions 5 and 10 also have the function to provide a free space for the ascent of a volume equal to the volume of concrete concrete displaced by the sealing rods 6 and 9 when the saddle is pressed into the concrete. On the other hand, stool 1 and 1 'comprise a plurality of apertures 7, 12 for the escape of air when the concrete fills the bowl constituted by the plate 3, its edge 11, and the bosses 5 and 10 .

Each stud is fixed to the sole by a force fit, or by welding. The threaded portion of the stud can be protected during all operations of insertion of the saddle by means of a plastic sleeve screwed on this threaded portion.

The method of the invention is applicable not only to this type of insert but also to any other type of insert can be sealed in concrete.

2 shows in section an example of track railway performed using this type of saddle and by applying the method according to the invention. This Figure 2 shows two rails 12 and 14 fixed respectively to two saddles 13 and 15 by nuts and pieces inserted in a conventional manner between each nut and the rail.

These two saddles 13 and 15 are sealed in a concrete slab 16 whose surface is flat, each of the two saddles 13 and 15 being pressed into the surface of the slab 16 to a depth such that the plane of these saddles is approximately in the plane of the surface of the slab 16. the concrete filled every seat and ensures a stronger anchor as if he was assured by the anchor rods.

The altitude of each of the rails 12 and 14 is determined partly by the elevation of the surface of the slab 16 which is manufactured with a given accuracy, of the order of a few millimeters, and secondly depends the depression of the seat into the concrete slab 16, this recess being adjusted so that the road surface has a given position, accurate to the millimeter. The spacing between the rails 12 and 14 is determined by the distance separating the two stools when they are sealed. There are no templates spacers between the rails, or a priori shim.

Figures 3 and 4 show respectively a top view and a main part sectional view of an exemplary insertion specially adapted for the insertion of the saddle type device shown in Figure 1. This example comprises a base consisting of a plate 30 designed to be placed directly on the surface 25 of a concrete slab 31 which is to be inserted in a seat. This concrete is fresh, smooth, and has a firm consistency. This plate 30 has a circular opening to which is welded a vertical tube 21 for the passage of a movable part.

This moving part comprises:<ul><li>a receptacle 28 of polyurethane, having an inner surface conforming to the shape of a saddle and comprising a flexible inner seal 29, the receptacle 28 based on the entire periphery of the saddle 1 by means of the seal 29; and receptacle 28 having a circular outer shape slightly smaller diameter than the tube 21 so as to be able to pass into the tube 21 while preventing a rise in the concrete in the tube 21 to confine the concrete;</li><li>a support plate 22 made of polyurethane, having a circular shape slightly smaller diameter than the tube 21, and supports particularly the receptacle 28 under this plate 22;</li><li>four elastic rubber blocks 24a, 24b, 24c, 24d, fixed to the plate 22;</li><li>two vertical arms 40a and 40b, fixed to the plate 22;</li><li>a vibration device 35, which is fixed on a steel plate 32, the latter being fixed to the top of the four resilient blocks 24a, 24b, 24c, 24d;</li><li>two clamps 23a and 23b, hydraulically operated, fixed to the plate 32, respectively and tightening the threaded rods of the two studs of the seat 1 (Figure 4 represents only the gripper 23a turning the set screw 2);</li><li>eight fingers positioning 26a to 26h, whose ends rest on the surface of horizontal saddle 1 remaining in contact with the walls almost vertical bosses 5 and 10 to give the saddle 1 a position well determined in the plane horizontal, each of these fingers sliding in a sheath, 27a to 27h, respectively, fixed to the plate 22; four fingers 26a-26d being integral with a part 33a (shown partially in figure4), and four fingers 26e to 26h is being secured to a workpiece not shown but homologous 33b secured to the part 33a by means of a bracket 39 that is seen from the side in Figure 4.</li></ul>

For clarity, Figure 3 does not represent the vibration device 35, or the parts 33a and 33b or the yoke 39. Figure 4 does not show the hydraulic hoses feeding the clamps and the vibration device.

The vibration device 35 includes one or more vibrators, each vibrator is constituted for example by a hydraulic motor having an unbalance. The entire vibration device 35 vibrates by driving in its movement the plate 32 which has a certain freedom through the resilient blocks 24a to 24d. The clamps 23a and 23b transmit vibrations to the anchor rods 9 and 6. Under the action of these vibrations, concrete is much more fluid in the vicinity of the anchor rods, thereby driving them with less force and to get a much more accurate positioning.

5 shows the set of this embodiment, representing further includes means for vertically displacing the support plate 22 and vertically moving the caliper 39. These means comprise:<ul><li>a horizontal beam 45 and two vertical cylindrical guides 43a and 43b, forming a portico;</li><li>a slider 42 sliding vertically while being guided by both 43a and 43b guides;</li><li>a first hydraulic cylinder 44 having one end fixed to the beam 45 and the other end fixed to the slider 42;</li><li>the two vertical arms 40a and 40b connecting the slider 42 to the support plate 22;</li><li>a second hydraulic cylinder 41 having one end fixed to the slider 42 and having its other end fixed to the bracket 39 which spans the vibration device 35;</li><li>and a CPU control unit connected:<ul><li>- A position sensor 46 fixed at one end to the beam 45 and the other to the slider 42 to determine the elevation of the saddle 1 relative to the plate 30 which rests on the surface 25 of the concrete slab 31;</li><li>- A solidarity CP position sensor of the beam 45, to determine the elevation of the plate 30 relative to a reference plane called laser plan because it is marked by a rotating laser beam in a given plane;</li><li>- The actuator 44 by two pipes to actuate;</li><li>- The cylinder 41 by two pipes to actuate;</li><li>- And the vibration device 35 by two pipes to operate it.</li></ul></li></ul>

The control unit UC controls several stages. Figure 6 illustrates a first step during which the seat 1 is positioned manually or automatically, inside the receptacle 28, by inserting the threaded rods of the studs in the hydraulic clamps 23a and 23b (The latter is not shown). The cylinders 44 and 41 are retracted, leaving the space between the tube 21 and the receptacle 28 for accessing the interior of the latter.

Figure 7 illustrates a second step in which the seat 1 is pressed rapidement.Pendant all this step, the vibration device 35 is activated with an amplitude and frequency adapted to to facilitate penetration of the seat 1 in the slab concrete 31, making it more fluid concrete in the vicinity of the anchor rods. 24a rubber blocks, etc ... allow the plate 32 to move slightly in all directions relative to the plate 22. The actuator 44 is actuated to push the saddle 1 to a position close to the position final planned, within a few millimeters. The actuator 44 moves: the slider 42, the arm 40a and 40b (not shown), the support plate 22 and the receptacle 28 associated to it. The seat 1 is pushed into the concrete liquefied by vibration. The receptacle 28 is lowered to be adjacent the surface 25 of the concrete slab. It should be noted that the guide fingers 26a, etc., are still in the raised position and are not in contact with the saddle 1.

Figure 8 shows a third step of inserting the saddle 1 of completing the depression to a lower speed suitable for accurate positioning, until the final planned depth for the seat. The actuator 44 is activated again, but with a lower speed. The vibration device 35 is on, but the amplitude and frequency of vibrations are suitable for precise positioning of the seat 1. The receptacle 28 and the plate 30, which are almost contiguous, confine the concrete and force him to go back in the protrusions 5 and 10. When the seat 1 has reached the intended position, the vibration device 35 and the actuator 44 are stopped.

9 illustrates a fourth step during which the vibration device 35 is stopped. The cylinder 41 is activated in turn. It lowers the bracket 39 which is secured to the part 33a (partially shown) and the part 33b (not shown), these parts 33a and 33b supporting the fingers 26a, etc. ... The yoke 39 is lowered until to abut on the plate 32. the ends of fingers 26a, etc. ... then come into contact with the saddle of the planar portion 1. If the seat 1 is not perfectly positioned in the horizontal plane, fingers rub against the vertical walls of the protrusions 5 and 10 of the saddle 1 and cause a slight displacement of the saddle 1, in the horizontal plane, to reposition the seat 1 in a well-defined position by the eight fingers. The vibrations ceased, concrete gradually resumes his firm. The clamps 23a, etc ... are kept tight, and the fingers 26a, etc. ... are held in this position until the increase in the viscosity of the concrete is sufficient to prevent any displacement of the seat in the rise of the fingers.

Hydraulic clamps 23a and 23b are then commanded to release the bolts of the saddle 1. Can the actuator 41 is activated in reverse to back the fingers 26a, etc ... Then the actuator 44 is activated in reverse to back up all moving part of the inserter.

Figures 10 and 11 respectively show two front views of a mobile machine for inserting two stools simultaneously. In Figure 10, the machine is in a condition to move and to prepare the inclusion of a saddle. In Figure 11, the machine is to insert a saddle in a concrete slab charges 62. Figure 12 shows a top view. In these figures, the machine has already inserted stool 70-76 in a concrete slab 62.

This embodiment comprises a mobile platform 52 supporting two insertion devices 51a and 51b identical to each other and which may be similar to the insertion device shown in Figures 3 to 5, and which has been described previously. They comprise in particular position sensors 64a, 64b respectively, analogous to the sensor CP; and control units UC1, UC2 respectively, similar to the control unit UC. 51a and 51b are mounted on a carriage 63 which is integral with the mobile 52 and platform relative to the latter along two horizontal axes orthogonal to each other. On the other hand, a set of jacks, not shown, allows to lower the devices 51a and 51b until their bases (sheet 30) rest on the surface of the concrete slab 62. The devices 51a and 51b through the carriage 63 through openings 61a and 61b respectively, and pass through the platform 52 by an opening 62.

The platform 52 is mounted on four tracks 53a, 53b, 53c, 53d, by means of four articulated horizontal arms 55a, 55b, 55c, 55d, for adjusting the spacing between the tracks, and through four vertical legs 57a, 57b, 57c, 57d, to independently adjust the height of each arm 55a, 55b, 55c, 55d, respectively, compared to the tracks 53a, 53b, 53c, 53d, resting on the ground.

The position of the platform 52 is controlled along three orthogonal axes, the means of a control unit UC3, so that it follows the expected profile of the raceway, therefore it follows the surface of the slab 62. the legs 54a and 54b respectively support 58a and 58b sensors that follow a guide 57 parallel to the longitudinal profile of the rails to install. The guide 57 carries pins, in order to slave the position of the platform 52 along two horizontal axes by referring to the guide 57. The platform 52 spans the concrete slab 62 and moves along the slab 62 through motors driving the caterpillars 53a, ..., 53d.

On the other hand, the legs 54a and 54b are respectively sensors 60a and 60b for determining the respective heights of the arms 55a and 55b with respect to a laser plane, given the height adjustment of the arm relative to the legs 54a and 54b. Knowing these altitudes allows tracking these altitudes to predetermined set values ​​for that platform 52 follows the track profile.

The concrete used has a firm consistency. The slab 62 has been fraîchementcoulée vibrated in place, rectified, and smoothed by a conventional slipform paver, such as those used to make concrete pavement, for motorway. It gives the surface of the slab a position deduced from the position intended for the track running surface with an accuracy of about 2 millimeters by conventional position servo.

Insertion devices stool, 51a and 51b, are spaced apart by an interval corresponding to the expected range for the rails. The mobile carriage 63 moves together and refines the insertion position with an accuracy of about a millimeter on two horizontal axes, even better than that provided by the platform 52.

The movable carriage 63 carries a position sensor 59 which allows tracking of the position of the carriage 63 along two horizontal axes, with reference to the position of the same guide 57, but with a finer tolerance than the tolerance on the position of the platform 52. the carriage is moved by two motors, not shown, controlled by a control unit UC4, based on measurements made by the sensor 59 and according to the position intended for both saddles to insert.

The enslavement of 51a and 51b insertion devices along a vertical axis, the control units UC1 and UC2, to insert each seat with a height accuracy of the order of a millimeter, even better than the accuracy obtained on the altitude of the surface of the concrete layer 62.

The position control device, referring to the position of a guide and the position of a laser plane, are conventional devices. But other known types of position control device could also be used to obtain an accurate position of each seat.

According to one embodiment, the insertion devices 51a and 51b could be mounted directly on the machine used to run up the concrete slab 62, instead of the platform 52. The realization of this machine is not described because it is similar to the embodiment of a machine conventionally used for making concrete highways.