EP3359744A1

EP3359744A1 - Retaining structure

Info

Publication number: EP3359744A1
Application number: EP16788735.5A
Authority: EP
Inventors: Thierry JEANMARIE; Pierre Schmitt; Michel COUDRY; Jean Michel JEANTY
Original assignee: Soletanche Freyssinet SA
Current assignee: Soletanche Freyssinet SA
Priority date: 2015-10-06
Filing date: 2016-10-05
Publication date: 2018-08-15
Anticipated expiration: 2036-10-05
Also published as: US10724199B2; FR3041976B1; CO2018003648A2; US20180313050A1; PL3359744T3; WO2017060630A1; MA42210B1; FR3041976A1; MA42210A1; EP3359744B1

Abstract

The invention relates to a retaining structure (12) in ground (S) comprising a vertical front part and delineating a first portion of ground (S1) from a second portion of ground. The front part (14) takes the form of a juxtaposition of bowed walls (16), each bowed wall (16) having a concave side facing the first portion of ground and a convex side facing the second portion of ground, and the retaining structure (12) further comprising a rear part (20) comprising a plurality of wall elements (22), the largest faces of which extend vertically into the second portion of ground (S2), each wall element (22) being positioned between two adjacent bowed walls (16) and being transverse to the front part (14).

Description

SUPPORTING WORK

Background of the invention

The present invention relates to retaining structures made in a soil, and in particular to works intended to form harbor wharf walls.

It relates more particularly to a retaining structure in a soil having a front portion extending substantially vertically while delimiting a first soil portion of a second portion of soil.

The invention finds particular interest when the levels of the first and second floor portions are substantially different, for example when the difference in height between the first and second floor portions is of the order of 15 to 30 m.

This is the case when the first portion of soil is located under a body of water, the front portion of the retaining structure then forming a quay wall also delimiting the water body of the second portion of soil.

Traditionally, the front part of such a retaining structure is a flat wall and part of the forces exerted by the second portion of soil on the front part is taken up by elongated metal tie rods which connect the flat wall to an anchor curtain rear, parallel to the flat wall, and located in the second portion of soil, away from the flat wall, which ensures the stability of the structure. The rear anchor curtain may be located more than 50 meters from the flat wall, and the metal tie rods may be positioned at a depth of about 5 meters. Conventionally, one begins by making the flat wall and the anchor curtain in the second portion of soil. Then the volume of soil is cleared on the distance separating the plane wall of the rear curtain, and on the depth to which the metal tie rods must be positioned.

It is therefore understood that the volume of soil that is necessary to clear to be able to put the metal tie rods is very important, and especially as the flat wall has a long length. In addition, after the laying of the metal tie rods, it is necessary to backfill the volume of soil that has been previously cleared. In general, an underground water table is present, which it is necessary to fold during the duration of the works.

These successive operations of tablecloth folding and terracing, which require moving very large volumes of soil are particularly long, tedious and expensive.

Object and summary of the invention

An object of the invention is to overcome the aforementioned drawbacks by proposing a retaining structure which is simpler and faster to achieve than that of the prior art, and which does not require the aforementioned earthmoving operations.

The invention achieves its object by the fact that the front part is in the form of a juxtaposition of vaulted walls extending in a longitudinal direction which is vertical,

each vaulted wall having a lower surface facing the first portion of soil and an upper surface facing the second portion of soil, and

the retaining structure further comprises a rear portion connected to the front part and comprising a plurality of wall elements whose largest faces extend vertically in the second floor portion, each wall element being disposed between two walls; adjacent vaults and being transverse to the front part.

It is understood that, considered in a horizontal sectional plane, the juxtaposition of the arched walls of the front portion has the form of a succession of arcs arranged side by side and whose intrados are turned towards the first portion of soil.

The wall elements are tie rods that extend vertically from the ground surface to a predetermined depth. The wall elements are integral with the front part over their entire height. Their function is to take over the forces on the vaulted walls and advantageously replace the elongated metal tie rods and the rear curtain of the prior art.

The wall elements are advantageously made from the ground surface. Consequently, according to the invention and contrary to the prior art, the installation of the tie rods is carried out without having to clear then backfill a large amount of soil. The invention therefore makes it possible to execute the retaining structure much more quickly as soon as it is freed from the earthworks.

Preferably, each wall element is disposed between two adjacent arched walls being orthogonal to the front part.

Advantageously, the upper level of the front portion substantially corresponds to the upper level of the rear portion. In other words, the upper faces of the vaulted walls are substantially at the same level as the upper faces of the wall elements.

Advantageously, the front portion has two vertical end edges, and the rear portion further comprises two other wall elements that are transverse to the front portion and disposed on either side of said plurality of wall elements in s extending from the vertical end edges of the front portion.

Advantageously, the wall elements are planar. Preferably, the front portion has a longitudinal direction and the wall members are perpendicular to said longitudinal direction of the front portion.

Advantageously, the wall elements are parallel to each other. Preferably, the wall elements are regularly spaced from each other.

According to an advantageous aspect of the invention, the wall elements have a greater height which is strictly less than the height of the front part. In other words, the depth of the wall elements is strictly less than that of the front part.

Thus, on the height of the wall elements, the retaining structure according to the invention behaves as a monolithic structure: each arched wall constituting the front part works in a vault like a circular wall, blocked at its ends by the wall elements , who work as tie rods. The above assembly, including the volume of soil contained between the wall elements, has a similar operation to that of a "wall weight". This makes it possible to substantially reduce the intensity of the bending moments applied to the front part, and to reduce the value of the displacements. In addition, below the wall elements, the retaining structure behaves like a conventional flat wall. In other words, the retaining structure according to the invention has a hybrid behavior.

Preferably, the height of the front portion is substantially equal to twice the greatest height of the wall elements. For the purposes of the invention, the "height" is considered in a vertical direction, while the "length" of the wall elements is considered in a horizontal direction.

The greatest height of the wall elements can be constant along the entire length of said wall elements. However, and advantageously, considered along its length, at least one of the wall elements has a first end connected to the front part, and a second end opposite the first end, and the height of the wall element. decreases from the first end to the second end of said wall member. This decreasing height has the advantage of reducing the stress concentration at the junction between the wall element and the vaulted walls which are immediately adjacent thereto. Another interest is to accompany the diffusion of the tensile stresses along the wall elements forming tie rods. Yet another interest is to reduce the amount of material needed to form the rear portion, which reduces the cost of the retaining structure. Preferably, the profile of the underside of the wall elements is stepped.

Preferably, the length of the wall elements is greater than the greatest height of said wall elements.

Advantageously, the distance between two adjacent wall elements is less than the length of one of the wall elements. Preferably, the distance between two adjacent wall members is substantially equal to half the length of one of the wall members. An interest is to improve the recovery of efforts by the rear part of the retaining structure.

According to a preferred embodiment, at least two vaulted walls are connected to each other and to one of the wall element by a coupling element which has a first connecting part connected to the wall element and second and third connecting portions connected to the two arched walls. It is understood that the arched walls act in compression on the coupling element. Advantageously, the front and / or rear parts are made of reinforced concrete.

Preferably, the vaulted walls comprise reinforcing cages which are arranged next to each other. In addition, when the rear part also contains reinforcements, these are connected to the reinforcement cages of the first part, preferably through the coupling elements, so as to achieve a structural continuity between the reinforcements of the front parts. and back.

According to a first embodiment, the front part and / or the rear part is a molded wall. When the front part is a molded wall, at least some of the arched walls preferably consist of a juxtaposition of planar unit screens arranged in an arc. The molded walls are conventionally executed by alternating or successive elementary panels. Forms at the ends, such as those described in document EP 0 101 350, may be used. Alternatively, with hacking-wall type tools, the connection between panels may be obtained by reeling the concrete of the already cast panel.

According to a second embodiment, the front part is made of reinforced concrete, while the wall elements comprise sheet piles.

According to another variant, the rear part is made using a "soil-mixing" technique, combining a step of excavating a trench and mixing in situ of the soil in place of the trench with a binder. . Possibly, sheet piles can then be placed in the trench.

According to yet another variant, the rear portion is made using the known grout wall technique, in which the frames may optionally be installed.

The present invention also relates to a port dock comprising at least one retaining structure according to the invention, wherein the first portion of soil is located under the bottom of a body of water so that the front part also delimits the plan of water from the second portion of soil.

This dock can be a dock, a river dock, or any other type of dock in contact with a body of water. Preferably, but not necessarily, the bottom of the body of water is between the lower level of the rear part and the level of the lower end of the front part.

Advantageously, the port dock according to the invention further comprises a first rail which is transverse to the wall elements of the rear part while being supported by several of said wall elements, and the port dock further comprises a second rail parallel to the first one. rail.

These two rails are a way for cargo handling cranes, such as container cranes, to move parallel to the longitudinal direction of the front part of the structure.

Preferably, the first rail is preferably fixed to the wall elements.

Preferably, but not exclusively, the second rail is supported by the front portion. Also, thanks to the invention, the first and second rails are supported by the retaining structure. Preferably, the rails are also integral with the retaining structure. As a result, the wall elements form crosspieces, which ensures a constant spacing between the two rails.

In addition, the weight of the container gantry is advantageously taken up by the retaining structure, which has the dual advantage of reducing the vertical forces to be taken into account for sizing the front part, and to avoid the risk of movement. differentials between the two rails, likely to occur with the retaining structures of the prior art.

Brief description of the drawings

The invention will be better understood on reading the following description of embodiments of the invention given as non-limiting examples, in which:

- Figure 1 is a perspective view of a port dock according to the invention consists of a retaining structure according to a first embodiment of the invention;

FIG. 2 is a sectional side view of the port dock of FIG. 1, on which a gantry crane has been shown. containers installed on a pair of rails supported by the retaining structure;

- Figure 3 is a top view of the port dock of Figure i;

- Figure 4 is a side sectional view of a variant of the port dock of Figure 1 comprising a retaining structure according to a second embodiment of the invention;

FIGS. 5A and 5B are comparative graphs illustrating displacement values and bending moments as a function of depth;

FIG. 6 is a top view in section of the harbor dock according to a first exemplary embodiment of the invention; and

- Figure 7 is a sectional top view of the port dock according to a second embodiment of the invention.

Detailed description of the invention

In Figure 1, there is illustrated a port dock 10 according to the invention, which comprises a retaining structure 12 in a soil S according to a first embodiment. The retaining structure 12 comprises a front portion 14 which extends substantially vertically, and which delimits a first portion of soil SI of a second portion of soil S2.

With reference to FIGS. 1 and 2, it can be seen that the first portion of soil S1 is situated under the bottom F of a body of water P and that the front portion 14 has a depth greater than that of the body of water. It is therefore understood that the front portion 14 of the retaining structure 12 also delimits the water plane P of the second portion of soil S2.

It is understood that the front portion 14 of the retaining structure constitutes a retaining wall whose function is to prevent the second portion of soil from collapsing in the water plane P.

As can be seen in FIG. 2, the height H1 of the front portion 14 of the retaining structure 12 is strictly greater than the height H2 of the water plane P, it being understood that the height H2 of the water plane P is defined between the bottom F and the surface of the water plane P. More specifically, the front portion 14 of the retaining structure 12 extends vertically below the bottom F of the water plane P on a height H3 . Also, the front portion 14 of the retaining structure 12 delimits the soil portion SI of the second portion of soil S2 on this height H3.

Furthermore, the front portion 14 of the retaining structure 12 extends vertically above the surface of the water plane P on a height H4.

In this nonlimiting example, the height H1 of the front portion 12 is 43 meters, the height H2 of the body of water is of the order of 25 meters, the height of the emergent portion H4 of the front portion 14 is the order of 6 meters. Finally, the height H3 of the portion of the front portion 14 which extends below the bottom of the water P is of the order of 12 meters.

According to the invention, the front portion 14 of the retaining structure 12 is in the form of a juxtaposition of arched walls 16 which extend in a longitudinal direction which is vertical. The arched walls are aligned by being arranged side by side so as to form a continuous wall which extends in a vertical vertical plane XI which extends in the longitudinal direction of the front part. As shown in Figure 3, each arched wall 16 has a cross section, taken in a horizontal plane, which generally has the shape of a circular arc.

Each arched wall 16 has a lower surface 18 facing the first soil portion S1, and also towards the water plane P. Each arched wall 16 also has an extrados 21, opposite the intrados 18, which is look at the second portion of soil S2.

In this example, each arched wall 16 has a thickness E1 which is of the order of 1 meter. It will further be understood that each vaulted wall 16 extends vertically from the surface along substantially the entire height H1 of the front portion 14 of the retaining structure 12. In this example, each vaulted wall 16, considered in a horizontal plane , has a radius of curvature, which is of the order of 15 meters.

The retaining structure 12 further comprises a rear portion 20 which is secured to the front portion 14 so as to form a monobloc structure. The rear portion 20 has a plurality of wall members 22 formed in the ground and extending vertically from the ground surface to a predetermined depth. It is therefore understood that the largest faces 24 extend vertically in the second portion floor S2. In the first embodiment illustrated in FIG. 2, the largest face 24 of the wall elements 22 has a substantially flat and rectangular shape.

With reference to FIG. 2, it can be seen that the upper level of the front part corresponds substantially to the upper level of the rear part. In other words, the wall elements 22, 26 extend vertically from the upper level of the front part. Moreover, the wall elements 22 are integral with the front portion 14 over their full height.

As can be seen in FIG. 3, each wall element 22 is secured to the front part by being disposed between two adjacent arched walls 16, while being transverse to the front part 14. More precisely, in this first embodiment, the wall elements 22 extend in vertical planes X2, which are perpendicular to the mean plane XI in which extends the front portion 14 of the retaining structure 12.

Furthermore, the wall elements 22 are parallel to each other, the distance d between two successive wall elements 22 being of the order of 15 meters.

In this first embodiment, the front portion 14 has two vertical end edges 14a and 14b, opposite to each other, as illustrated in FIG. 3. The rear portion 20 further comprises two other wall elements 26 which are also transverse to the front portion 14, and which are arranged on either side of the plurality of wall elements 22. These other wall elements 26 extend from the end edges 14a, 14b of the front portion 12, so that all the wall members 22,26 are parallel to each other.

More precisely, in this first embodiment, the wall elements 22, 26 are identical and parallel to each other, so that only the wall element 22 which is illustrated in FIG. 2 will be described.

Advantageously, the wall elements 22, 26 have a greater height H5M, which in this example is constant over the entire length of the wall elements. In addition, all the wall elements 22, 26 have the same height. However, without leaving the In the context of the present invention, the wall elements could have different heights.

The greatest height H5M is strictly smaller than the height H1 of the front part 14. Moreover, the depth of the wall elements 22, 26 is strictly smaller than that of the front part 14.

This conformation has the effect that, according to the height H5M, the retaining structure behaves as a circular wall, while below the wall elements 22,26, the retaining structure behaves as a flat wall.

Moreover, in the example of FIG. 2, it can be seen that the level of the bottom F of the water plane P lies between the lower level 14a of the front portion 14 and the lower level 20a of the rear portion 20. The lower level 14a of the front part 14 corresponds to the lower end of the arched walls, while the lower level of the rear part corresponds to the lower face of the wall elements 22,26.

In this example, the height H1 of the front portion is substantially equal to twice the greatest height H5M of the wall elements 22,26. In this example, the wall elements extend along a length L which is oriented horizontally. The length L of the wall elements 22, 26 is greater than the greatest height H 5 M of said wall elements, as illustrated in FIG. 2.

In addition, the distance d between two adjacent wall members 22,26 is substantially equal to half the length L of the wall members 22,26. Such a configuration makes it possible to improve the retaining properties of the retaining structure according to the invention.

Referring again to FIG. 3, it can be seen that at least two adjacent arched walls 16 are connected to each other and to one of the wall elements 22 by a coupling element 30 which presents a first connecting portion 30a connected to the wall member 22 and first and second connecting portions 30b, 30c connected to the two adjacent arched walls. This coupling element 30 facilitates the securing between the arched walls and the connecting element.

Referring again to FIG. 2, it can be seen that the port wharf 10 further comprises a first rail 40 and a second rail 42, parallel to the first rail 40 on which a container gantry 50 can move parallel to the front portion 14, to load a cargo ship 52.

The first rail 40 is transverse to the wall members 22,26 while being supported by said wall members 22,26. The second rail 42 is, in this example, supported by the front portion 14. Without departing from the scope of the present invention, the second rail 42 could also be supported by the wall members 22,26. In this example, the first and second rails 40, 42 are attached to the retaining structure 12.

In Figure 4, there is illustrated another port dock 10 'according to the invention, which comprises a retaining structure 12' according to a second embodiment of the invention.

Considered according to its length L, each wall element 22 'has a first end 22'a which is connected to the front portion 14' and a second end 22'b which is opposite the first end

22'a.

The retaining structure 12 'according to this second embodiment differs from the first embodiment in that the wall elements 22' of the rear portion 20 'have a non-uniform height.

As illustrated in FIG. 4, considered along the length of the wall element, the height of said wall element 22 decreases between the first end 22'a and the second end 22'b of the wall element 22. As shown in FIG. 4, the lower face 22 'c of the wall element 22' has a stepped shape, the greatest height H5M of the wall element 22 'being close to the front portion 14'.

We will now describe an example of method of realization of the port docks described above.

In order to create the harbor dock 10, for example, the front part 14 of the retaining structure 12 is started. To do this, a molded wall of depth H1 is formed in the ground S whose cross section, taken in a plane horizontal, has the shape of a succession of arcs, as shown in Figure 3. This molded wall is reinforced concrete. To do this, we can use a drilling tool, such as that described in EP 2 295 648. Then, or concomitantly, one carries out the wall elements 22,26, either in the form of molded walls, or by carrying out excavations by a technique of "soil-mixing" in which one introduces sheet piles. To do this, it will be possible to use a drilling and mixing tool, such as that described in FR 2 889 608. The coupling elements 30 are furthermore placed between the wall elements 22 and the arched walls 16

In the examples of FIGS. 6 and 7, the coupling elements 30 ', 30 "are constructed with the tooling used to make the front part.

This is for example a molded wall tool implementing formwork such as those described in EP 0 101 350, which make it possible to achieve the connections between the coupling element and the arched walls.

FIG. 6 illustrates a first embodiment of the coupling elements 30 '. In this first example, the first connecting portion 30'a is coupled with the wall member 22 by shape cooperation. In this first example, the wall element 22 is made of molded wall with continuous reinforcements, as described in document EP 0 833 987 for example. It can be seen that the armature cage 31 'of the coupling element 30' is connected to the armature cage 23 of the wall element 22. Each of the second and third connection portions 30'b, 30'c is also provided with a reinforcement cage and is in the form of a connecting arm which is coupled with one of the arched walls 16 by shape cooperation.

In the second exemplary embodiment illustrated in FIG. 7, the coupling element 30 "is similar to that of FIG. 6 except that the second and third connecting portions 30" b and 30 "c have the recess shape and not connecting arm The arched wall 16 which is connected to the second connecting portion 30 "b consists of two unitary elements 16i and I6 ₂ connected to each other.

Furthermore, in this second exemplary embodiment, the wall element 22 comprises a sheet pile wall 25 connected to the armature cage 31 "of the coupling element 30". This sheet pile curtain can be directly beaten in the ground, or set up in the excavation by the technique of "soil-mixing", as described above, or in wall well known grout elsewhere. To produce the wall elements 22 'of the second embodiment of FIG. 4, four adjacent trenches are dug, the respective heights of which decrease between the first end 22'a and the second end 22'b. The staircase shape illustrated in FIG. 4 is then obtained.

In FIG. 5A, the curve Gl illustrates the displacement in millimeters of the retaining structure 12 of FIG. 1 as a function of the depth, measured from the surface of the water plane P. The curve G2 illustrates the displacement of a retaining structure according to the prior art described above.

In FIG. 5B, the curve M1 illustrates the value of the bending moments experienced by the retaining structure 10 of FIG. 1 as a function of the depth. Curve M2 illustrates the value of the bending moments experienced by the retaining structure according to the prior art described above.

It is apparent from the calculations that the retaining structure according to the invention has displacement and bending moments which are, in absolute value, substantially lower than those of the previous structure.

Claims

1. Retaining structure (12,120 in a soil (S) having a front portion (14) extending substantially vertically while delimiting a first soil portion (S1) of a second soil portion (S2), characterized in that than

the front portion (14) is in the form of a juxtaposition of vaulted walls (16) extending in a longitudinal direction which is vertical, in that

each vaulted wall (16) has a lower surface (18) facing the first soil portion (S1) and an upper surface (21) opposite the second soil portion (S2), and in that

the retaining structure (12) further comprises a rear part (20) connected to the front part (14) and comprising a plurality of wall elements (22) whose largest faces (24) extend vertically in the second soil portion (S2), each wall member (22) being disposed between two adjacent vaulted walls (16) and being transverse to the front portion (14).

The retaining structure of claim 1, wherein the front portion (14) has two vertical end edges, and wherein the rear portion (20) further includes two other wall members (26) which are transverse to the front portion (14) and disposed on either side of said plurality of wall members (22) extending from the vertical end edges (14a, 14b) of the front portion.

3. Retaining structure according to claim 1 or 2, wherein the wall elements (22,26) are planar.

The retaining structure of any one of the preceding claims, wherein the wall members (22,26) are parallel to one another.

The retaining structure of any one of the preceding claims, wherein the wall elements (22, 26) have a greater height (H5M) which is strictly less than the height (H1) of the front part (14).

6. Retaining structure according to claim 5, wherein the height (H1) of the front portion is substantially equal to twice the largest height (H5M) of the wall elements (22,26).

7. Retaining structure according to claim 5 or 6, wherein, considered according to its length (L), at least one of the wall elements (2 has a first end (22'a) connected to the front part (140). , and a second end (22'b) opposite the first end (22'a), and wherein the height of the wall member (22) decreases between the first end (22'a) and the second end (22'a); 22'b) of said wall member (22).

A propped structure as claimed in any one of the preceding claims, wherein the length (L) of the wall members (22,26) is greater than the greatest height (H5M) of said wall members.

The retaining structure of any preceding claim, wherein the distance (d) between two adjacent wall members (22,26) is less than the length (L) of one of the wall members (22). , 26).

The retaining structure according to any one of the preceding claims, wherein at least two adjacent arched walls (16) are connected to each other and to one of the wall element (22) by an element of coupling (30,30 ', 30 ") having a first connecting portion (30a, 30'a, 30" a) connected to the wall member (22) and second and third connecting portions (30b, 30c 30'b, 30'c; 30 "b, 30" c) connected to the two adjacent vaulted walls.

11. Retaining structure according to any one of the preceding claims, wherein the front portions (14) and / or rear (20) are made of reinforced concrete.

The propped structure according to any one of the preceding claims, wherein the front portion (14) and / or the rear portion (20) is a molded wall.

13. Retaining structure according to any one of the preceding claims, wherein the front portion (14) is reinforced concrete, while the wall elements comprise sheet piles.

14. A harbor pier (10) comprising at least one retaining structure (12) according to any one of the preceding claims, wherein the first portion of soil (SI) is located under the bottom (F) of a plane of water (P) so that the front portion (14) delimits the water plane (P) of the second soil portion (S2).

Port pier according to claim 14, characterized in that it further comprises a first rail (40) which is transverse to the wall elements (22,26) of the rear part while being supported by a plurality of said wall elements (22,26), and in that the port dock further comprises a second rail (42) parallel to the first rail.

16. Harbor pier according to claim 15, characterized in that the second rail (42) is supported by the front portion (14).