WO2021015623A1

WO2021015623A1 - A foundation system for a floating object

Info

Publication number: WO2021015623A1
Application number: PCT/NO2020/050193
Authority: WO
Inventors: Per Gunnar TILSETH
Original assignee: P.G. Tilseth As
Priority date: 2019-07-23
Filing date: 2020-07-07
Publication date: 2021-01-28
Also published as: NO20190916A1; NO346060B1

Abstract

A foundation system for a floating object (1), comprising one or more foundation assemblies (9), which are placed in a zone (Z), extending at a distance between firm ground and out above a body of water. Each foundation assembly (9) comprises a carrying structure (9a) with a first support device (9c) for releasable support of a portion of the floating object (1). The foundation device is fixedly founded on a bed under a body of water. A floating buoyancy body (4) for releasable support of a portion of the floating object (1) is placed in a respective foundation assembly (9).

Description

A foundation system for a floating object Field of the invention

The invention relates to a foundation system and anchoring system for a floating object. The floating object can for example be a barge, a floating dock or a floating bridge. The floating object is anchored to a fixed object, such as dry land, a fixedly grounded object or the like.

Background of the invention

Floating bridges are well-known structures and are used as foundation for i.a. roadways for motor traffic, footpaths and bicycle paths, railway lines, etc. The floating bridges can be equipped with their own buoyancy chambers and float directly on the water, or they can comprise a bridge body, which is placed on floating pontoons. The pontoons can be dimensioned for the desired weight load and with a height that ensures the desired vertical clearance under the bridge body. A floating bridge can comprise several sections (lengths) of bridge bodies, which are coupled together, thus forming a floating bridge with the desired length.

Floating bridges are coupled together with fixed objects on land, for example a road or a railroad line. This coupling must be constructed, so that the variations between low tide and high tide onshore are taken into consideration. This difference between low tide and high tide can be considerable, in many places above a 10 metre vertical rise. It is known that in some cases, it has been decided to build the transition between the land and the floating bridge to be so rigid and strong, that the floating pontoon at low tide is pressed into the water and at high tide is suspended in mid-air, so that it constitutes a load on the bridge. Other variations have a hinged module against the land that moves together with the tide. This results in a bend exactly where the hinges are, which is unfavourable, e.g. in a roadway.

Therefore, there is a need for a device between a fixed point (e.g. on land) and a floating bridge or the like, which takes into consideration the differences between low tide and high tide better than the prior art solutions, and so that undesired bends in, or unfavourable loading on, a roadway or railroad line may be avoided. The prior art includes JP 2001220710 A, which describes a floating object with a foundation system having foundation devices placed in a zone which extends a distance betwwen firm ground and out above a body of water.

Summary of the invention The invention is disclosed and characterized in the independent claim, whilst the dependent claims describe other characteristics of the invention.

Therefore, at foundation system for a floating object is provided, comprising one or more foundation assemblies placed in a zone that extends a distance between firm ground and out above a body of water; wherein the extent of the zone is mainly determined by the difference between high tide and low tide at the relevant location; and wherein at least one foundation assembly is fixedly founded on a floor under a body of water; characterized in that each foundation assembly comprises a carrying structure with a first support device for releasable support of a portion of the floating object; and each foundation assembly comprises a buoyancy body placed floatingly in the body of water for releasable support of a portion of the floating object.

The foundation system can further comprise one or more foundation units placed on firm ground, above a water surface, for releasable support of a portion of the floating object that projects above said firm ground.

The foundation assembly further comprises a second support device, which is dimensioned and configured to carry the buoyancy body.

In one embodiment, the first support device comprises a wear surface for abutment against the floating object.

The first support device can comprise a wear surface for abutment against the floating object. The buoyancy body can comprise a support structure for centring of the buoyancy body against a floating object.

Several buoyancy bodies can be joined together via attachment means. In one embodiment, the second support device is placed at a vertical distance from the first support device.

The floating object can be a bridge body.

The invention provides a connection device between a floating body and a stationary installation or an area. The invention is particularly suitable as a land coupling between floating bridges and the land. The transition zone of the foundation system is dimensioned according to the current local conditions and are configured to be so long and flexible that the bridge body is allowed to follow high tide and low tide, and the buoyancy body supports the structure at flow tide (high tide). The foundation system according to the invention will provide a sufficiently long and flexible transition between firm ground and a floating bridge, which will not affect traffic in any way.

Brief description of the drawings

The aforementioned and other characteristics of the invention will be further explained in the following description of an embodiment, presented as a non-limiting example and with reference to the accompanying drawings, wherein:

Fig. 1 is a sectional drawing along the sectional line (axis) A-A in Fig. 4 and shows the foundation system according to the invention viewed from one side at high tide;

Fig. 2 is an enlarged drawing of the field marked I in Fig. 1; Fig. 3 is an enlarged drawing of the field marked II in Fig. 1;

Fig. 4 is a schematic diagram of the foundation system according to the invention viewed from above, showing the facility installed in a floating bridge (only part of the floating bridge is shown, and the bridge body is shown in broken lines);

Fig. 5 is an enlarged drawing of the field marked III in Fig. 4;

Fig. 6 is an enlarged drawing of the field marked IV in Fig. 4; Fig. 7 is an isometric drawing of the facility according to the invention;

Fig. 8 is an isometric drawing of the area marked V in Fig. 7, wherein the bridge body and the roadway are drawn in broken lines;

Fig. 9 is a sectional drawing along the sectional line (the axis) A-A in Fig. 4 and shows the foundation system according to the invention viewed from one side at low tide;

Fig. 10 is an enlarged drawing of the field marked VI in Fig. 9; and Fig. 11 is an enlarged drawing of the field marked VII in Fig. 9;

Detailed description of an embodiment The following description will use expressions as "horizontal", "vertical", "lateral", "back and forth", "up and down", "upper", "lower", "inner", "outer", "forward", "rear", etc. These expressions essentially refer to the perspectives and locations showed in the drawings and related to a normal use of the invention. The expressions are used only to facilitate the comprehension of the description and should not be limiting. The expressions "high tide" and "low tide" do not indicate absolute terms, but should be understood as a higher and a lower water level, respectively.

Fig. 1 illustrates an embodiment of the foundation system according to the invention for supporting a floating bridge with a floating object 1, here in the form of a bridge body 1. The bridge body, which can comprise a roadway, a footpath and bicycle path, a railroad or similar known devices, is at one end anchored to firm ground R by a per se known anchoring 11 and is supported by pontoons 2, 4, which are placed floatingly in a body of water W. It should be understood that the figures only show part of a floating bridge; the bridge body 1 can be supported by several pontoons (not shown) and extend further to another fixed point (not shown) and also be anchored there. The invention is aimed at a foundation system for the floating bridge in a transition zone Z between firm ground (e.g. a point on land) and to a floating pontoon 2, which is placed (at a distance from the anchoring 11) in the body of water. A skilled person will understand that the extent of this zone Z is mainly determined by the difference between the highest and the lowest water level (high tide and low tide) at the relevant location.

Fig. 1 shows the foundation system at high tide. A pontoon 2 of a type which per se is known floats in the water surface S and supports a portion of the bridge body 1. The pontoon 2 is anchored to a fixed point (e.g. the seabed T) via anchoring means 2a. The bridge body and the pontoon 2 can be releasable or fixedly attached to each other, or the pontoon 2 can be an integrated part of the bridge body. It should be understood that the bridge body can be supported by several such pontoons (not shown). It should also be understood that this part of the bridge body can be equipped with own buoyancy chambers and thereby can float directly in the water surface without need for pontoons.

The foundation system is arranged in a transition zone Z between the pontoon 2 and the anchoring 11 and comprises one or more foundation assemblies 9 and one or more foundation units 5. Fig. 1 shows two foundation assemblies 9 and four foundation units 5, but the invention shall not be limited to this number. In principle, the foundation unit 5 is a fixed support, such as a beam, sleeper or the like, which is placed on firm ground, and which supports a portion of the bridge body. The bridge body 1 is not attached to the foundation units 5, but rests on these due to its weight.

The foundation assembly 9 will subsequently be described with reference to Figs 2, 3, 7, and 8. In the illustrated embodiment, the foundation assembly 9 comprises a carrying structure 9a,b,c for the bridge body 1 and for a buoyancy body 4, here in the form of a pontoon 4. The carrying structure comprises legs (e.g. columns) 9a, which are placed on firm ground such as the seabed T (Fig. 3) or other firm ground R (Fig. 2), a first support device 9c (for the bridge body 1) and a second support device 9b (for the buoyancy body 4). In this illustrated embodiment, the second support device 9b comprises horizontal beams 9b that extend between the legs 9a, which are dimensioned and configured to carry the buoyancy body 4, when it is in a low position (shown in broken lines in Fig.

2). The second support device 9b is placed at a distance h from the first support device 9c, and this distance is preferably so large that the buoyancy body 4 is below the first support device 9c at low tide. The second support device 9b can also have other configurations, such as brackets attached to one or more of the legs, as long as it fulfils its primary function, which is to be a releasable support device for the pontoon 4.

In the illustrated embodiment, the first support device 9c (see e.g. Fig. 8) comprises horizontal profiles 9b arranged at the top of the legs 9a and is configured and dimensioned to carry a portion of the bridge body 1. The horizontal profiles 9b can advantageously be equipped with a wear surface 16 to dampen impacts from the bridge body 1. The first support device 9c can also have other configurations, as long as it fulfils its primary function, which is to be a releasable support device for a portion of the bridge body 1. The buoyancy body (the pontoon) 4 is equipped with a support structure 13, which is configured for centring of the buoyancy body 4 against the bridge body 1. It can advantageously be equipped with a wear surface 14.

The pontoons 4 are secured against undesired movement in the longitudinal direction of the bridge body 1 and relative to their respective foundation assembly 9, by means of attachment means 7, here in the form of a chain 7 that extends between the pontoons and is anchored to firm ground R. Each foundation assembly 9 is equipped with guide devices 17, here in the form of slits or splits on each leg, which ensure that the pontoons are centred in the foundation assembly 9. An optional cross-coupling 18 of rope, wire or chain will provide extra securing of the position of the pontoon 4 relative to the foundation assembly.

Figs 1, 2 and 3 show the foundation system according to the invention at high tide. The pontoons 4 are lifted upwards by the body of water due to their buoyancy and supports the bridge body 1. Fig. 2 shows that the pontoon 4 lifts the bridge body 1, so that it does not touch the foundation unit 5 that is closest to the body of water. The other foundation units 5 support the bridge body 1.

Figs 9, 10 and 11 show the foundation system according to the invention at low tide. In this condition, the pontoon 4 has moved so far downwards that it no longer supports the bridge body 1, but the bridge body rests on (is supported by) the first support device 9c. The bridge body also rests on the foundation units 5.

Claims

1. A foundation system for a floating object (1), comprising

- one or more foundation assemblies (9) placed in a zone (Z) that extends a distance between firm ground (R) and out above a body of water (W); wherein the extent of the zone (Z) is mainly determined by the difference between high tide and low tide at the relevant location; and wherein at least one foundation assembly (9) is fixedly founded on a floor (R; T) under a body of water (W); characterized in that

- each foundation assembly (9) comprises a carrying structure (9a) with a first support device (9c) for releasable support of a portion of the floating object (1); and

- each foundation assembly (9) comprises a buoyancy body (4) placed floatingly in the body of water (W) for releasable support of a portion of the floating object (1).

2. The foundation system of claim 1, further comprising one or more foundation units (5) placed on firm ground (R), above a water surface (S), for releasable support of a portion of the floating object (1) that projects above said firm ground.

3. The foundation system of claim 1 or claim 2, wherein the foundation assembly (9) comprises a second support device (9b), which is dimensioned and configured to carry the buoyancy body (4).

4. The foundation system of any one of claims 1-3, wherein the first support device (9c) comprises a wear surface (16) for abutment against the floating object (1).

5. The foundation system of any one of claims 1-4, wherein the buoyancy body (4) comprises a support structure (13) for centring of the buoyancy body (4) against a floating object (1).

6. The foundation system of any one of claims 1-5, wherein several buoyancy bodies (4) are joined together via attachment means (7).

7. The foundation system of any one of claims 3-6, wherein the second support device (9b) is placed in a vertical distance ( h ) from the first support device (9c).

8. The foundation system of any one of claims 1-7, wherein the floating object (1) is a bridge body.