FR2680531A1 - Prefabricated retaining wall (breast wall) made of two elements: wall and base frame (footing) - Google Patents

Abstract

The present invention relates to the prefabrication of retaining walls made from two elements: the vertical partition part of the wall (1) on the one hand, and the base frame (footing) (2) on the other hand. The wall (1) is reinforced with a panel of welded wire mesh (reinforcement mat) (3), the supporting wires (4) of which have a spacing e. Bent rods (6) are inserted into the middle of the supporting wires (4) of the welded wire mesh panel (mat) (3) in order to provide anchoring of the wall into the base and, together with the latter, to resist bending loads. The bent rods (6) will become incorporated, as the wall is erected, between the supporting steel (11) and distribution (spreading) steel (12) of the upper mat of welded wire mesh (10) of the base. The retaining walls thus built may be in straight alignment, but also follow curves and exhibit discontinuities in plane.

Description

 The present invention relates to the prefabrication of retaining walls made of two elements: the vertical wall or wall on the one hand and the flange-frame on the other.

 Part of the sole is cast on site.

 Prefabricated retaining walls exist, but they are monobloc: wall and sole form a whole.

 These prefabricated retaining walls are heavy, but above all very bulky during transport. Indeed, the width of the sole being of the order of half the height of the wall, these are real T-shapes that must be transported by bending to the requirements of the road gauge (width: 2.50 m and height).

 These two drawbacks, weight and size, greatly limit the use of such prefabricated retaining walls.

 The present invention allows more flexibility.

 The fact of dissociating wall and footing also splits the weight of the whole, which makes it possible to use less significant lifting means or to make walls of greater height.

 Transport is done simply by stacking, flat, reinforced concrete slabs of width less than or equal to 2.50 m and of variable length.

The sole element is constituted by a reinforced concrete frame which has many advantages
- Reduced weight.

 - I1 allows easy positioning on site of the low and high reinforcement of the sole made up of welded mesh panels.

 - Easy installation of the wall resting on the sole-frame which ensures the stability of the whole thanks to a practical shoring.

 - I1 serves as peripheral formwork for the poured sole in use.

 The advantage of prefabricated retaining walls is above all to avoid formwork on site. This is the case with the present invention. Making a part of the sole on site is a very simple operation: rapid reinforcement and pouring requiring no formwork.

 The wall and the base frame are prefabricated horizontally on standard formwork tables allowing widths of 2.50 m.

 The wall can have a profile of constant thickness or better a profile of variable thickness. For example, 10 cm minimum thickness at the top of the wall and a thickness variation of the order of 5 cm / m.

 Profiles of variable thickness are more interesting because they allow on the one hand the lightening of the wall and on the other hand they better adapt the bending forces to inertias.

 The wall is reinforced with a welded mesh panel, the supporting wires of which have a spacing e preferably equal to 10 cm and the distributing wires of which have a spacing E preferably equal to 30 cm.

 All the elements of welded mesh used for the reinforcement of the wall and the sole, will imperatively have an identical spacing e, the spacing E may possibly differ.

 This panel of welded mesh reinforcing the wall is completed by an element comprising bent bars regularly spaced from e and welded to transverse bars distributing and ensuring the connection.

 The bent bars will be inserted in the middle of the carrying wires of the welded mesh panel to anchor the wall in the sole and with the carrying wires of the welded mesh.

resist bending forces.

 The wall will include a number of slightly conical and regularly distributed holes serving on the one hand as barbican and on the other hand allowing the fixing of the connecting devices of the props and lifting slings.

 The very tight reinforcement of the base of the wall does not allow the incorporation of barbicanes, also the water will be collected by a horizontal drain resting on the sole at the back of the wall.

However the lower corners of the wall will be slightly bevelled to allow a small evacuation of the water to the right of the joints.

 The wall is cast flat on the formwork table, the frames positioned downwards with the wedges corresponding to the coatings.

 The top edge of the wall will be boxed with an iron U, U of 100 mm for example.

 The opposite side of the formwork will be closed by another U of a height equal to the thickness of the base of the wall.

 In order to form the base of the wall by letting the bent bars pass, the formwork will be made in three parts preferably in neoprene.

 - A first plate with a chamfer is placed over the entire width of the table, under the set of bent bars. Its thickness is equal to the coating of steels, 3 cm for example.

 - Between the bent bars are inserted parallelepipedic elements including the elbows.

 On the latter another chamfered plate of the entire width of the formwork is put in place, its upper level reigns with the top of the U.

 The side walls of the wall will be shuttered by folded sheet metal elements having the longitudinal profile of the wall.

These folded sheet metal elements, regularly attached to the folding panels of the formwork table, have a rounded portion at their upper part which makes it possible to form the external angle of the wall and to serve as a support for a vibrating rule raising the surface of the concrete.
On each element of folded sheets is welded an angle which will form a triangular notch on the cheeks of the wall. For example 5 cm from the rear face.

 The joint between two walls will be of the order of 15 to 20 mm in width. Thanks to the shape of the cheeks, it will be possible to treat the seal between two wall elements to a greater or lesser extent depending on the degree of seal which one wishes to give to the joint.

 The sole frame is a reinforced concrete frame of constant thickness, for example 20 cm. It has two trapezoidal elements connected by two rectangular elements.

 The trapezoidal element located at the front of the sole, has its widest horizontal face, 20 cm for example, located upwards and its narrowest face downwards.

 The trapezoidal element located at the rear of the sole has an identical profile but its widest horizontal face is on the contrary located downwards.

 The inclined faces of the trapezoidal elements are oriented in such a way that the forces applied to the sole plate place the concrete poured in place on the precast concrete.

 The trapezoidal elements are reinforced by triangular chains plated against the inclined faces. They also include steel anchoring turns, of the ARTBEON type for example, which will make it possible to screw the wall shoring devices to the vertical frame on the sole frame.

 The two rectangular elements are reinforced by machine-shaped reinforcement, made up of two longitudinal reinforcements connected by a continuous wire, inclined and welded in steps of 20 cm, for example. They also include semi-cylindrical reservations spaced from E on the inner faces at the top and bottom. These reservations make it possible to accommodate the ends of the distribution wires of the welded mesh.

The formwork of the base frame is carried out simply on the formwork table
The outside faces of the rectangular elements are shuttered by the folding panels of the shuttering table.

 Two U irons of height equal to the thickness of the sole frame form the outer walls of the trapezoidal elements.

On these two U's, devices will be set up to include the anchoring turns of the ARTHEON type, for example.

 The inner faces of the sole frame are shuttered by shuttering elements of triangular section, of width equal to E and of the same height as the sole frame. These formwork elements are placed side by side, bases alternately arranged downwards and upwards. This allows the width of the base to be dimensioned by adding more or less formwork elements. If, for example, 20 cm and 5 cm are respectively the two widths of the trapezoidal elements, the width of the sole, also dimensioned by calculation, will be equal to ((n - 1) * E) + 25 cm, (n being the number of formwork elements used). We can thus obtain sole widths equal, for example, to 55, 85, 115, 145, 175, 205, 235, 265 cm.

The ends of the triangular formwork elements comprise semi-cylindrical tenons, suitably installed which make it possible to reserve in the rectangular elements of the sole frame the notches intended to allow the accommodation of the ends of the distribution wires of the welded mesh panels.

The implementation of these prefabricated walls is as follows:
cleanliness concrete is poured on site, possibly with steps to the right of the joints.

 Four lifting slings anchored in the anchoring turns of the ARTHEON type, the cadressemelle is placed on the cleanliness concrete by crane.

 The bottom reinforcement of the sole, consisting of a simple welded mesh panel, is implemented with the usual wedging devices.

 Similarly, the high reinforcement, also consisting of a welded mesh panel, is put in the same way in the high position.

 Wall lifting slings are fixed on two reserved holes from the top of the walls (barbican holes).

 The wall elements are then brought to the crane, the bent bars being inserted between the load-bearing and distribution wires of the upper welded mesh panel.

 The wall elements, resting on the sole frames, are then supported by adjustable stays taking support on the one hand in the anchoring turns of the sole frame and on the other hand in the conical holes of the barbican walls.

 A shooting bar is then implemented in the lower part and in the center of the bent bars to improve the anchoring.

The concrete used on the site is then poured
When the concrete is set, the props can be removed.

 A possible treatment of the sealing of the joints is then carried out.

 The walls can then be drained.

 The resistance of the concretes obtained, the backfilling is carried out.

 The retaining walls thus formed can be in straight alignment, but also follow curves and have plan recesses.

 We will successively examine the curved and recessed walls.

 Curved walls are made up of elements such as those previously described, regularly installed, tangent to the desired curvature and of divided wall elements.

The latter, of smaller width, are manufactured in the same way. Their edges presenting only an inclination necessary for a good connection between elements
The bent bars also spaced from e will fit into a radiant reinforcement spaced from e to the right of the wall.

This reinforcement will mainly consist of frames.

 The formwork of the base being simply produced by sheets of the same height as the base bolted into the anchoring turns of the base frames.

 Figures 12 & 13 will show more clearly the layout of such walls.

 In the same way figure 14 is an example of walls with notches and connections in length which we will describe later.

 Figures 1 & 2 respectively represent the vertical section and the cross section on the wall (1) and the sole frame (2).

 The welded mesh panel (3) is composed of carrier wires (4) spaced from e and distribution wires (5) spaced from E. The bent bars (6), inserted in the middle of the carrier wires (4), will have their own distribution bars (7) -, possibly welded to ensure their connection and anchoring.

 These figures show an example of installation of the barbican (8) as well as the slightly angled lower corners of the wall (9).

 Similarly the bent bars (6) will be incorporated into the mounting of the wall between the bearing steels (11) and distribution (12) of the upper welded mesh panel (10) of the sole.

 These figures also show, in the part corresponding to the sole, the bottom reinforcement consisting of a welded mesh panel (13) consisting of carrier wires (14) spaced from e and distribution wires (15). On this panel (13) and the bent bars (6) are the strip bar (16) improving the anchoring.

 The sole frame (2) is composed of two trapezoidal elements (17) and two rectangular elements (18).

 The trapezoidal elements (17) are reinforced by triangular linkages (19), they also include steel anchoring turns (20).

 The rectangular elements (18) are armed with two longitudinal frames (21) connected by a continuous, inclined and welded wire (22).

 We can also see in Figure 2 the shoring device of the wall (1) on the sole-frame (2) consisting of adjustable stays (23) taking support on the one hand in the anchoring turns (20) of the frame-sole and on the other hand in the conical holes of the barbican (8) of the walls.

FIG. 3 represents a top view of the sole-frame alone before fitting the welded mesh panels (10) & BR <(13). We can see the semi-cylindrical notches (24) allowing the housing of the ends of the welded mesh panels. The anchor turns (20) are also represented there.
Figure 4 shows the formwork of the inner faces of the base frame (2) made by formwork elements of triangular section (25) placed side by side, bases alternately arranged downward and upward.

 FIG. 5 represents the section of the sole frame (2) on the ends of the elements (25), which makes it possible to show the semi-cylindrical tenons (26) which make it possible to reserve in the rectangular elements (18) of the sole frame notches (24) intended to allow the housing of the ends of the distribution wires (15) & (12) of the bottom (13) and top (10) welded mesh panels.

 FIG. 6 shows the reinforcement of the rectangular elements (18) of the sole frame made up of two longitudinal reinforcements (21) connected by a continuous wire (22), inclined and welded.

 Figure 7 shows the section on the wall formwork (1).

The wall is cast flat on the formwork table, the frames positioned downwards with the wedges corresponding to the coatings. The top and bottom edges of the walls are coffered respectively by U (27) & (28). We can note in this figure the formwork cones (29) of the barbican (8). These cones can, for example, include a magnetic fixing base if the shuttering table is metallic.

 The formwork of the base of the wall is shown on a larger scale in Figure 8. It will be made in three parts preferably in neoprene.

 - A first plate (30) comprising a chamfer is placed over the entire width of the table, under the set of bent bars (6). Its thickness is equal to the coating of steels.

 - Between the bent bars are interposed parallelepipedic elements (31) including the elbows.

 On the latter another chamfered plate (32) of the entire width of the formwork is put in place, its upper level reigns with the top of the U (28).

Figure 9 shows the cross section of the shuttering table (33) which has folding panels (34)
Figure 10. shows on a larger scale the area corresponding to the folding panels (34). We can see the folded sheet elements (35) serving as formwork for the side walls of the wall.

These folded sheet metal elements (35), regularly fixed to the folding panels (34) of the formwork table (33), have at their upper part a rounded portion (36) making it possible to form the external angle of the wall and to serve as a support. has a vibrating rule raising the surface of the concrete
On each element of folded sheets is welded an angle (37) which will form a triangular notch (38) on the cheeks of the wall.

 The profile of the joint between two wall elements is shown in Figure 11, we can note the triangular notches (38) and the rounded (39) corners of the walls.

Figure 12 shows an example of curved walls made by four wall elements (1) and sole frames (2). The axes of symmetry (40) of these elements making between them angles of 300. The walls are connected by elements of divided walls (41), their edges (42) making with the rear face (43) an angle of 1050,
Figure 13 shows another example of curved walls made by three wall elements (1) and sole frames (2).

The axes of symmetry (40) of these elements making between them angles of 450. The walls are connected by elements of divided walls (41), their edges (42) making with the rear face (43) an angle of 112.50.

 Figures 12 & 13 show two examples of regular curves of minimum radius, it is of course possible with such walls to follow any curvature.

Figure 14 shows an example of walls with recesses and connections. Let's analyze this figure from left to right:
10 recess: the front facing of the first wall element is aligned with the end of the second. A connecting element (44) will rest and be anchored in the sole frame.

It will be joined to the two adjoining walls by bolted metal legs and brackets. The end of the second wall (45) will have a fruit.

This is an example of an outgoing angle offset.

 20 offset: Example of an inward angle offset.

A connecting element (46) will rest and be anchored in the sole frame. In the same way, it will be secured to the two adjoining walls by bolted metal legs and brackets. His left song (47) will present a counter fruit.

 Length connection: to end up with the recess with a re-entrant angle, it turns out to be necessary to have a connection element (48) which is fixed on the two adjoining walls and is anchored in a cast sole in place. The edges of the latter being shuttered by bolted plates in the adjoining sole frames.

 The recess is an example of a recessed angle recess, while the recess is an example of an outgoing angle recess.

 FIG. 14 has thus treated by example the various cases encountered of outgoing and returning angles and of connection.

Claims (11)

RESELL ZCATOMS  1) Prefabricated retaining walls, characterized on the one hand by its manufacture in two elements: the vertical wall or wall (1) and the base frame (2) and on the other hand by its technique of implementation  2) Wall (1) according to claim 1, characterized by its reinforcement consisting of bent bars (6) regularly spaced from e and being inserted in the middle of the carrying wires (4) also spaced from e of a lattice panel welded (3). Said bent bars (6) will anchor the wall in the sole and with the supporting wires (4) resist bending forces.  3) Wall (1) according to claim 1 fi 2, comprising a number of holes (8) slightly conical and regularly distributed serving as barbican, characterized in that said holes (8) also allow the fixing of device shoring (23) and lifting slings.  4) Wall (1) according to claims 1 to 3, characterized by the formwork of its base made in three parts: a first plate (30) comprising a chamfer is placed over the entire width of the table (33), under the set of bent bars (6). Between the bent bars (6) are interposed parallelepipedic elements (31) including the elbows. On the latter another chamfered plate (32) of the entire width of the formwork is put in place, its upper level reigns with the top of the U (28).  5) Wall (1) according to claims 1 to 4, characterized by the formwork of its side cheeks made of folded sheet metal elements (35), regularly fixed to the folding panels (34) of the formwork table (33), comprising their upper part is rounded (36) making it possible to form the external angle of the wall (39) and to serve as a support for a vibrating ruler raising the surface of the concrete. On each element of folded sheets is welded an angle (37) which will form a triangular notch (38) on the cheeks of the wall.  6) sole-frame (2) according to claim 1, characterized in that it is composed of two trapezoidal elements (17) and two rectangular elements (18). The trapezoidal element located at the front of the sole, has its widest horizontal face, situated upwards and its narrowest face downwards. The trapezoidal element located at the rear of the sole has an identical profile but its widest horizontal face is on the contrary located downwards. The inclined faces of the trapezoidal elements are oriented in such a way that the forces applied to the base plate place the concrete poured in place on the precast concrete.  7) Sole frame (2) according to claims 1 & 6, characterized in that the trapezoidal elements (17) are reinforced by triangular chains (19), they also include steel anchoring turns (20) which allow the attachment of shoring device (23) or lifting slings.  8) Sole frame (2) according to claims 1, 6 and 7 characterized in that the rectangular elements (18) are armed with two longitudinal frames (21) connected by a continuous wire, inclined and welded (22). These so-called rectangular elements (18) include notches (24) intended to allow the housing of the ends of the distribution wires (15) & (12) of the bottom (13) and top (10) welded mesh panels.  9) Sole frame (2) according to claims 1, 6, 7 and 8 characterized by its formwork of the inner faces, produced by formwork elements of triangular section (25) placed side by side, bases alternately arranged downwards and up. The ends of said triangular section formwork elements (25) include semi-cylindrical tenons (26), which allow the notches (24) to be reserved in the rectangular elements (18).  10) Prefabricated retaining walls, according to the preceding claims, characterized by its implementation technique for incorporating the welded mesh panels (10) and (13) in the sole frame (2) before putting in place the wall (1). The bent bars (6) will be incorporated between the bearing steels (11) and distribution (12) of the upper welded mesh panel (10) of the sole. On the panel (13) and the bent bars (6) are the strip bar (16) improving the anchoring.  11) Prefabricated retaining walls, according to the preceding claims, characterized by the possibility of producing curved walls and recesses at an outgoing angle and at an incoming angle, thanks to different elements of divided walls: elements of divided walls (41), whose edges (42) form an angle with the rear face (43); fractional connecting wall elements (44) &(48); fractional connecting wall elements (46) whose edge (47) has a counter-fruit.