FR2802225A1 - Method and tool for back-filling a trench in the ground particularly long trenches beside a roadway, uses blade with broad edge and carried on parallelogram mechanism to push soil into trench then to compact soil - Google Patents

Abstract

The back-filling uses the same tool (32) to push soil back into the trench, in one position, and to compact soil returned to the trench (51) in the other position. One edge (36) of the tool is widened to compact the soil. The tool is carried on a deformable parallelogram (43) attached to a self-propelled tractor. The tool is carried under a vibrator mechanism (42).

Description

The present invention relates to a method for backfilling a trench.

The present invention also relates to a tool for the implementation of the method.

It is currently known to dig trenches at a rate of 1000 to 3 meters per day, especially for laying cables along roadways. The main obstacle to the highly desirable speed for such work is the trench filling operations, for which no satisfactory solution is known.

Backfilling requires the land to be dumped back into the trench by the digging machine, which is located along the trench on either side of the trench as two windrows. In addition, the earth must be compacted in the trench. It is not sufficient to perform the compaction after complete filling because, in a known manner, compaction only concerns the upper layer of soil. On the contrary, it is necessary to alternate the filling and compacting phases if the upper surface of the closed trench is to be stable after the end of the work.

Manual filling is known, the compaction being carried out using a groomer that can be manipulated by hand. Shovel compaction is still known, the bucket of which is alternately used to shovel the earth from the windrows into the trench and then to tamp the earth at the bottom of the trench. Both processes are extremely slow. Large diameter compacting wheels are also known which can roll over the earth dumped at the bottom of the trench to compact it. Compaction wheels are usually associated with vibrators to improve the compaction effect. To compact earth in a trench one meter deep, you need a wheel three meters in diameter so that its axis is located above the ground. Peripherally driven compacting wheels are also known which can thus have a diameter only slightly greater than the depth of the trench, but wheels are expensive and fragile. In addition, compaction wheels do not solve the problem of filling.

The object of the invention is thus to provide a method and a tool for considerably improving the efficiency of trench filling operations and in particular long trenches formed along the circulation channels.

According to the invention, the method for backfilling a trench by means of a self-propelled machine equipped with a mechanical tool-holding arm, in which filling phases and compaction phases are alternated, is characterized in that the phases are carried out. Filling and compaction with the same tool which is moved obliquely as a pushing blade along one edge of the trench to drive the soil into the trench when filling and plunge longitudinal orientation into the trench. trench for compaction.

Thus, the same tool can be used successively for filling and compacting operations for each of which it is sufficient to properly adjust the tool and then move the self-propelled machine along the trench. For example, it is possible to move the machine in one direction for a filling phase, then in the other direction for the compaction of soil that has just been poured into the trench during the filling phase, then to make a new filling pass. in the first direction for a remainder of land on the same edge the trench or for the earth forming a windrow on the other edge of the trench, then again in the said other direction a new phase of compaction and so on. The process according to the invention makes it possible to recap and compact the trench at substantially the same rate, for example approximately 1000 to 3000 meters per day, as that of the machine for digging and installing cable or piping which operates further ahead of the building site. mobile.

By using a self-propelled machine equipped with an improved mechanical arm, it is possible to fix the tool with a final adjustment to the fifth wheel constituting the end of the mechanical arm of the self-propelled machine. The tool can then be given all the positioning and orientation settings that are practically useful for the different work phases by using all the degrees of freedom offered by the self-propelled machine between said fifth wheel and its chassis oriented to progress parallel to the trench. There is a particularity in the trade of mechanical arms allowing pivoting between a distal portion and a proximal arm portion about a substantially vertical lateral offset axis. This allows the self-propelled machine to be offset laterally with respect to the trench, and for example to be on the roadway extending along the trench, without this conditioning the orientation of the tool seen from above with respect to the longitudinal direction of the trench.

It is further provided according to a preferred version of the invention to adjust the inclination of the tool seen in cross section. In particular, when according to a preferred version a base of the tool is used as the compacting face, the tool can be oriented so that in cross-section this base is horizontal during compaction and, on the contrary, has a clearance angle behind the edge. scraping during refilling. Without limitation, this tilt adjustment is achievable with an adjustable side offset arm of the kind explained above. effect, by orientation of the proximal portion of the arm in the vertical plane, we can give a certain inclination to the axis of lateral offset "substantially vertical". Depending on the lateral offset angle, given to the distal portion of the arm, said inclination of the lateral offset axis makes it possible to incline more or less the fifth wheel in the direction of an inclination of the tool as seen in section. cross.

The mechanical arms generally comprise a so-called "digging" jack which makes it possible to orient the tool-carrying saddle, for example to actuate the excavator bucket with respect to the arm in conventional applications. According to the invention, by this jacking cylinder or any other appropriate means, the tool is oriented in the plane of its thrust face, in particular so as to place the scraping edge in contact with ground side slope bordering the trench during the plugging or else to give the compacting surface a certain pitching angle with respect to the longitudinal direction of the trench during compaction.

During compaction, it is preferred according to the invention to pull the tool, so that the tool is at the rear of the harness, and let the tool self-position longitudinally in the trench. The angular clearance needed for this purpose does not need to be large since the machinist will place the saddle in approximately proper position. The small angular deflection desirable may be simply provided by mechanical games.

According to a version of the implementation of compaction according to the invention, the tool is left to move vertically or substantially vertically relative to the end of the arm during compaction. Thus, the tool compacts by its own weight, preferably with the aid of a vibrator. Due to the substantially vertical freedom of movement, the vibrations are not transmitted to the mechanical arm. It is also possible to prestress the tool down during compaction, preferably by means of elastic means respecting freedom of movement above height. This freedom of movement has the additional advantage of allowing the tool to be positioned on the necessarily uneven surface of the trench bottom fill.

According to a second aspect of the invention, tooling for the implementation of a method is characterized in that it comprises an elongate tool having a longitudinal thrust face having a lower edge of scraping and secondly to the base of the tool a compacting face, - mounting means on a mechanical arm, and - between the mounting means and the tool, connecting means for immersing the tool longitudinally in a trench.

Other features and advantages of the invention will emerge from the description below, relating to non-limiting examples.

In the accompanying drawings - Figure 1 is an elevational view with a longitudinal section of the trench showing the tooling associated with the self-propelled machine, the view being schematic in that it has not shown the turret 9 and the mechanical arm 3 in the oblique perspective that should result from the shift of the machine relative to the cutting plane 1a trench; - Figure 2 is a top view, on an enlarged scale, of the region of the end of the mechanical arm and the front portion of the tool; - Figure 3 is a schematic elevational view of the tooling and the end of the mechanical arm, the view being simplified by removing the angular offset A1 of Figure 2; - Figure 4 is a rear view of the tool; - Figure 5 is a schematic view of the self-propelled machine and the tool during a compacting phase, in top view; - Figures 6, 8 are three cross-sectional views of the trench 51 during three successive phases of compaction; - Figures 7, 9 11 are side views respectively corresponding to Figures 6, 8 and 10, with longitudinal section of the trench; - Figures 12 to are four views in section and perspective illustrating the tooling in four possible modes of implementation for the refilling; FIGS. 16 to 19 are views similar to FIG. 5 but relating to the four filling modes of FIGS. 12 to 15 respectively; - Figure 20 is a cross sectional view of the tool during filling; and FIG. 21 is a sectional view transverse to the trench, with a perspective view of the tooling during refilling from an initial ground sloping sideways.

In the example shown in FIG. 1 and in the form of an enlarged detail in FIG. 2, the tool 1 according to the invention is attached to the tool-carrying saddle 2, forming the mobile end of the mechanical arm 3 of a self-propelled machine 4. The machine 4 has a chassis 6, consisting of a chassis 7 equipped with driving wheels 8, and a turret 9 pivoted relative to the chassis 7 around a turret axis 11 which is vertical when the wheels 8 rest on a horizontal ground. The mechanical arm 3 is an example of a known improved mechanical arm comprising a proximal portion 12 connected to the turret 9 and a distal portion 14 composed of an intermediate arm 16 and an end arm 17. The proximal portion 12 comprises a proximal beam 21 articulated to the turret 9, along a first transverse axis 13. The intermediate arm 16 comprises an intermediate beam 18, one end is articulated along a second transverse axis 19 to the proximal beam 21 and other end is articulated along a third transverse axis 22 to an extreme beam 23 of the end arm 17. At its end opposite to the intermediate beam 18, the end beam 23 is articulated along a fourth transverse axis 24 to the tool-carrying saddle 2. The mechanical arm 3 comprises a proximal cylinder 26 mounted for adjust the height orientation of the proximal beam 21 relative to the turret 9, an intermediate cylinder 27 é to adjust the height orientation of the intermediate beam 18 relative to the proximal beam 21, an end cylinder 28 mounted to adjust the height orientation of the end beam 23 relative to the intermediate beam 18, and a cylinder of recess 29 to adjust the orientation of the tool-carrying seat 2 around the fourth transverse axis 24 relative to the end beam 23. In addition, the articulation between the proximal beam 21 and the intermediate beam 18 comprises, in a manner which is only symbolized, means making it possible to orient the distal portion 14 relative to the proximal portion 12 of the mechanical arm about a substantially vertical lateral offset axis 31 by a substantially vertical axis 31. Actuators of the jack type, not shown, are provided to control the value of the lateral offset angle of the distal portion 14 relative to the proximal portion 12. According to the orientation of the proximal beam 21 about the inclination axis 13, the axis of the Lateral port 31 is strictly vertical when the undercarriage 6 rests on a single plane, or on the contrary has an inclination in the vertical plane of the proximal beam 21, as is illustrated by positions 31a and 31b of the axis 31 to the Figure 1 for two opposite inclinations of the axis 31.

There are commercially available mechanical arms having substantially the degrees of mobility which have just been described, for example that marketed in France under the trade name MECALAC, manufactured by (MECALAC, 74292 ANNECY LE VIEUX, France).

The tooling and the method according to the invention are not limited to a particular type of mechanical arm nor more generally of self-propelled machine, but we began by describing an example of these in order to then be able to explain more easily the different functions of the tooling of the process.

As shown in FIG. 1 and in more detail in FIGS. 3 and 4, the tooling 1 comprises a substantially rectangular blade-shaped tool 32 comprising two opposite symmetrical thrust surfaces 33 for the earth, which terminate at their base. The two faces 33 diverge relative to each other downwardly so that the two scraping edges 34 are spaced from one another. There is between the two edges 34 a plane compacting face 36, perpendicular to the main plane, the blade 32 and forming the base of the tool 32. At its two longitudinal ends, the compacting face 36 is terminated by spatulas 37 which give it the shape of a two-way ski. scraping edges 34 are rectilinear and parallel to each other.

There is between the saddle 2 and the tool 32 a mounting flange 39 under the fifth wheel 2 and means designated by the general reference 38 for the connection between the mounting flange 39 and the tool 32. The connecting means 38 comprise a downward support 41 secured to the underside of the sole 39, a vibrator 42 disposed at a distance above the tool 32 and behind the support 41, a deformable parallelogram link 43 between the support 41 and the vibrator 42, and a column 44 rigidly connecting the upper edge 46 of the tool 32 with the movable member of the vibrator 42. As illustrated in particular in Figure 1, the column 44 is provided high enough to allow to dive the tool 32 to the bottom 47 of a trench 51 while maintaining the vibrator 42 and the support 41 above the level of the natural ground 48.

The sole 39 is fixed to the saddle 2 with the possibility of angular adjustment in the generally horizontal plane of the fifth wheel 2 as illustrated by circumferentially elongated holes 49 in the fifth wheel 2 in FIG. angular orientation such that the main plane of the tool 32 forms an angle A1 (Figure 2) of the order of 30 with the plane of the distal portion 14 of the mechanical arm 3. Thus, as shown in Figure 5, the tool 32 may be arranged longitudinally in the trench 51 for compaction while the undercarriage 6 of the self-propelled machine rests on a roadway 52 located parallel to the trench 51 and progresses along the roadway 52, thus parallel to the trench 51 The turret 9 can then typically form with the longitudinal axis 53 of the undercarriage 6 an angle A2 = Al while the lateral offset angle of the distal portion 14 relative to the proximal portion 12 about the lateral offset axis 31 is set to zero. In this attitude, the self-propelled machine can progress in the sense that its mechanical arm is directed forward and the tool 32, under the effect of its own weight, essentially vertical vibrations produced by the vibrator 42 and a if necessary preload applied downward in a manner to be described later, continuously compacting the earth that has been poured into the trench 51 during a previous phase of refilling.

The deformable parallelogram 43 comprises two superposed arms 54 each articulated to the support 41 by a respective axis 56 and to the frame of the vibrator 42 by respective axis 57. The axes 56 and 57 are perpendicular to the plane of the tool 32 so that the assembly constituted by the tool 32 and the vibrator 42 can move up and down while the two scraper edges 34, seen in elevation as in Figure 3, retain an orientation defined by the angular position of the saddle 2, itself defined in particular by the digging cylinder 29.

At the same time as allowing the essentially vertical mobility of the tool 32, deformable parallelogram 43 establishes a longitudinal distance between the support 41 and the tool 32 so that, as shown in FIG. 5, the tool 32 is pulled behind fifth wheel and support during compaction. The axes and 57 have operating clearances so that the tool 32 can self-orient itself like a self-steering wheel, inside the trench 51.

Figures 6 to 11 show three successive stages of compaction of the embankment in the trench 51 which has been equipped with a cable 58 and has each time undergone a preliminary step of filling which will be described in more detail below. These figures show, as also Figure 1, that it is provided according to the invention to give the compacting surface 36, during compaction, a certain angle of rotation A3 (Figure 7) with respect to the direction longitudinal 59 of the trench, that is to say an angle by which the compacting face its front end relative to the direction of travel a little higher than its rear end. The machinist sets the angle A3 for example by means of the digging cylinder 29 of the mechanical arm. As further shown in FIG. 3, the connecting means 38 comprise return and damping means 61 which tend constantly to return the arms 54 of the deformable parallelogram 43 towards an average orientation substantially parallel to that of the compacting surface 36. The return and damping means 61 comprise in the example shown a plate 62 rigidly fixed to the support 41 between the two arms 54 and a respective elastic block 63 interposed between the plate 62 and each arm. The blocks 63 serve as dampers and at the same time allow the mechanical arm 3 to transmit the fifth wheel 2 to the compacting surface 36 compaction prestressing downwards without removing the vertical movement of the tool 32 and vibrator 42 relative to the support 41 and the rest of the machine. Figures 12 to 15 illustrate the implementation of the process and the tooling during the filling phases. In this case, the tool 32 rests on the initial floor 48 on one side of the other of the trench 51 with its scraping edges 34 which form in the horizontal plane an angle A9 of approximately, for example, with the direction longitudinal of the trench 51 and therefore with the direction of progression of the self-propelled machine along the trench. For filling, the self-propelled machine can be used in forward or reverse, the tool is either pulled or pushed through the deformable parallelogram 43. It has proven effective to activate the vibrator 42 even for refilling, especially when the soil is sticky. For each direction of operation, choose one or the other of the two opposite inclinations of the tool with respect to the longitudinal direction of the trench according to whether one re-closes from one side or the other of the trench 51, the thrust face 33 which is active to pour into the trench 51 the ground forming the windrows 64 is always that which is turned obliquely to the trench 51.

There are therefore four possible work situations, illustrated in FIGS. 12 to 15. In FIG. 12, the machine progresses in progress before the rear edge 66 of the tool 32 is further away from the running track 52) of the running gear. of the machine (not shown 'this figure) that the front edge 67 and' is the windrow 64 located between the trajectory of the running gear trench 51 which is at least partly dumped in the trench 51.

In the situation shown in FIG. 13, the orientation of the tool 32 is substantially the same as in FIG. 12 but the tool rests on the initial floor 48 situated on the other side of the trench 51 and the gear progresses in reverse.

In the situation shown in FIG. 14, it is now the front edge 67 which is further from the trajectory of the running gear than the rear edge 66, the machine progresses in reverse and the tool 32 pours into the trench 51. the earth from the windrow 64 located between the trench and the trajectory of the running gear.

Finally, in the situation shown in Figure 15, the orientation of the tool is substantially the same as in Figure 14 but the tool works on the other side of the trench 51 and the machine progresses in the forward direction .

FIGS. 16 to 19 respectively show, in top view, the situations of FIGS. 12 to 15, and illustrate the use of the offset angle A7 around the lateral offset axis 31 to obtain the different angular orientations desired for the tool 32 in these different cases.

Thus, for all the filling and compacting operations of a trench 51, the self-propelled machine 4 always evolves parallel to the trench 51 and on the same side thereof.

As shown in FIG. 20, for the filling phases, it is advantageous to give the tool 32 in cross section an angle of inclination A4 towards the earth of the windrow 64 to be forced back into the trench 51. point down the active scraping edge 34 which is at the base of the active thrust face 33 and the compacting face 36 is given with respect to the horizontal a clearance angle A5 equal to the angle of inclination A4. This gives the tool 32 a tendency to scrape the earth from below instead of letting it "float" over a layer of soil that would form a carpet on the natural ground 48.

In the example of a self-propelled machine illustrated in FIG. 1, it is possible to realize the inclination angle A4 of the tool choosing a suitable inclination of the proximal beam 21 to give the lateral offset axis 31 a position such that 31a or 31b suitably inclined so that the lateral offset angle A7 chosen in each case as shown in Figures 16 to 19, at the same time produce the desired inclination A4 for the tool.

FIG. 21 illustrates that the tool 32 is even able to perform filling from a natural ground 48 at the lateral slope A6, giving the scraping edge 34 a corresponding inclination allowing it to be in contact with such a device. ground all along its length. Such inclination of the tool is achievable by appropriate control of the digging ram 29 for example.

By reversing control of the digging ram 29, the soil could be backfilled from a soil rising laterally from the trench 51.

Of course, the invention is not limited to the examples described and shown.

In particular, the tool could be used with a mechanical arm different from that described and shown, with for example a hinge about a longitudinal axis between the mechanical arm and the turret or between two successive parts of the mechanical arm. The tool can be used in particular with a less advanced mechanical arm than that described, provided, for example, to modify the orientation of the tool relative to the harness between the different work phases, or by providing adjustment axes between the tool saddle and the tool, for example an axis parallel to the length of the tool to be able to place it in a vertical position during compaction and with an inclination as shown in Figure 20 during the filling.

Claims (1)

<U> CLAIMS </ U> 1- A process for backfilling a trench (51) by means of a self-propelled machine (4) equipped with a mechanical tool-holding arm (3), in which alternating quenching phases and compaction phases, characterized in that the filling and compaction phases are carried out with the same tool (32). - that is moved in oblique orientation (A9) as a pushing blade on the ground (48) bordered trench (51) to drive the earth (64) in the trench when filling, and - that we plunge in longitudinal orientation in the trench (51) for compaction. 2- Method according to claim 1, characterized in that the tool (32) is given two oblique orientations (A9) opposite to the longitudinal axis (59) of the trench (51) to perform two passes filling with opposite directions of movement along the same edge of the trench (51). 3- A method according to claim 1 or 2, characterized in that for compacting is placed the tool (32) substantially in vertical plane so as to use as a compaction surface (36) an enlarged base of the tool (32), formed along a lower edge (34) of a thrust face (33) for driving the soil during filling. 4. The method of claim 3, characterized in that during compacting is placed the compaction surface (36) at a slight angle of rotation (A3) relative to the longitudinal axis (59) of the trench (51). 5- Method according to claim 3 or 4, characterized in that during the filling is given to the tool (32) seen in a cross-sectional plane an inclination (A4) towards the earth to push, so as to point to the ground a scraping edge (34) extending between the compaction surface (36) and the thrust surface (33). 6. Method according to one of claims 1 to 5, characterized in that it vibrates the tool (32) at least during compaction. 7. Process according to one of claims 1 to 6, characterized in that the self-propelled machine (4 on the same side of the trench (51) is placed for all the filling and compacting operations. according to one of claims 1 to 7, characterized in that said phases are successively moved of the machine (4) in one direction and in the other along the trench (51). one of claims 1 to 8, characterized in that for the filling is given to the tool seen along the longitudinal axis (59) of the trench angle of devers (A6) to place its base in contact with a ground in lateral slope along the trench 10- Method according to one of claims 1 to 9, characterized in that for modifying the orientation of the tool seen from above with respect to the longitudinal axis (59) of the trench (51) the geometry of the self-propelled machine is modified between its frame (7) and an end (2) of the arm (3) to the The method according to claim 10, characterized in that, to modify the geometry, the orientation of a turret (9) of the machine pivotally mounted on the chassis (7) is adjusted. ), and a lateral offset angle (A7) of a distal portion (14) of the mechanical arm (3) relative to a proximal portion (12) of the mechanical arm. 12- Method according to one of claims 1 to 11, characterized in that during compaction pulling the tool leaving him a freedom of self-orientation in the trench (51). 13- Method according to one of claims 1 to 12, characterized in that during compacting the tool is left free to self-positioning height in the trench (51). 14- Method according to one of claims 1 to 13, characterized in that during compaction prestressing tool (32) downwards. 15- Tooling for the implementation of a method according to one of claims 1 to 14, characterized in that it comprises - an elongate tool (32) having a longitudinal thrust face (33) having a lower scraping edge) and on the other hand at the base of the tool a compacting face (36), - mounting means (39) on a mechanical arm (3), and - between the mounting means (39) and the tool (32), connecting means (38) for immersing the tool longitudinally in a trench (51). 16- Tooling according to claim 15, characterized in that the tool has two opposite thrust faces (33) each having a lower scraping edge (34), and in that the compacting face (36) extends between the two scraping edges (34). 17- Tooling according to claim 15 or 16, characterized in that the tool (32) has the general shape of a blade associated with the connecting means (38) by an upper edge (46) opposite the scraping edge (34). ). 18- Tooling according to one of claims 15 to 17, characterized in that the mounting means (39) are adjustable in orientation of the tool (32) seen from above. 19- Tooling according to one of claims 15 to 18, characterized in that the compacting face (36) is terminated spatula (37) at at least one of its ends. 20- Tooling according to one of claims 15 to 19, characterized in that it further comprises a vibrator (42) for actuating the tool (32) in vertical vibrations. 21- Tooling according to one of claims 15 to 20, characterized in that the connecting means (38) allow a clearance in height between the mounting means (39) and the tool (32) equipped with the vibrator (42) . 22- Tooling according to one of claims 15 to 20, characterized in that the connecting means (38) allow a clearance in height between the mounting means (39) and the tool (32). Tooling according to Claim 21 or, characterized in that the connecting means (38) comprise damping and / or return means (61) towards an average level of tool (32) relative to the mounting means ( 39). 24- Tooling according to one of claims 21 to, characterized in that the connecting means (38) comprise a deformable parallelogram arrangement (43) between the mounting means (39) and the tool (32) to allow said deflection of the tool while transmitting an angular positioning. 25- Tooling according to one of claims 15 to 24, characterized in that in view from above its longitudinal direction forms an angle (A1) relative to the orientation provided for the distal portion (14) of a mechanical arm (3) carrying the tools. 26- Tooling according to one of claims 15 to 25, characterized in that the connecting means (38) establish in top view a distance between the mounting means (39) and the tool (32).