U.S. patent application number 12/282092 was filed with the patent office on 2009-12-10 for a floating pontoon body to be tied together with at least another pontoon body.
Invention is credited to Arild Ovretveit.
Application Number | 20090304448 12/282092 |
Document ID | / |
Family ID | 38509712 |
Filed Date | 2009-12-10 |
United States Patent
Application |
20090304448 |
Kind Code |
A1 |
Ovretveit; Arild |
December 10, 2009 |
A FLOATING PONTOON BODY TO BE TIED TOGETHER WITH AT LEAST ANOTHER
PONTOON BODY
Abstract
The invention relates to a floating pontoon body (13) of
concrete, configured to be tied together with at least another
pontoon body (11,12,13) in order to provide a interconnected
floating body (10), where the pontoon body (13) comprises a deck
slab (15) of concrete and at least down from the deck slab (15),
along the periphery of the deck slab extending vertical walls
(16,16') of concrete, forming a hollow body, and where said pontoon
element (13) along its side edges is configured with upper and
lower pulling ducts intended to receive tensioning cables (14) or
the like, intended to tie together two or more pontoon elements
(11,12,13) both along their upper and lower side edges. At least
the pulling ducts extending along the lower edges are configured in
such way that it is possible to add on one or more new pontoon
elements subsequent to a stage where two or more pontoon elements
already are connected, tied together and installed.
Inventors: |
Ovretveit; Arild;
(Porsgrunn, NO) |
Correspondence
Address: |
ROTHWELL, FIGG, ERNST & MANBECK, P.C.
1425 K STREET, N.W., SUITE 800
WASHINGTON
DC
20005
US
|
Family ID: |
38509712 |
Appl. No.: |
12/282092 |
Filed: |
March 9, 2007 |
PCT Filed: |
March 9, 2007 |
PCT NO: |
PCT/NO2007/000093 |
371 Date: |
February 6, 2009 |
Current U.S.
Class: |
405/26 ;
114/65A |
Current CPC
Class: |
B63B 35/38 20130101;
B63B 5/14 20130101; B63B 35/34 20130101; E02B 3/064 20130101; E02B
3/062 20130101 |
Class at
Publication: |
405/26 ;
114/65.A |
International
Class: |
B63B 35/38 20060101
B63B035/38; B63B 5/14 20060101 B63B005/14; E02B 3/06 20060101
E02B003/06 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 10, 2006 |
NO |
20061144 |
Claims
1.-14. (canceled)
15. Floating pontoon body of concrete, configured to be tied
together with at least another pontoon body in order to form an
interconnected floating body, where the pontoon body comprises a
deck slab of concrete and vertical walls of concrete extending
downwards from the deck slab along the periphery of the deck slab,
forming a hollow body, and where said pontoon element long the top
and bottom side edges of the vertical walls is configured with
upper and lower pulling ducts intended to receive tensioning cables
or the like, intended to tie together two or more pontoon elements
both along their upper and lower side edges, characterized in that
said pulling ducts are terminated at a level above the sea level
when the pontoon is floating in a floating condition, the lower
pulling ducts at the lower edge of the vertical walls extending in
a skewed manner up from the lower side edges of the pontoon
body.
16. Floating pontoon body according to claim 15, wherein the
pulling ducts have a slightly curved or more or less straight
portion extending from their lower portion at one side edge and up
to the termination at a level above the sea level.
17. Floating pontoon body according to claim 15, wherein the
pulling ducts are terminated in one end wall of the pontoon
body.
18. Floating pontoon body according to claim 15, wherein the lower
pulling ducts being terminated in the deck slab.
19. Floating pontoon body according to claim 15, wherein the
termination for the pulling ducts are arranged at a distance away
from the end surface of the pontoon element.
20. Floating pontoon body according to claim 15 wherein the pulling
ducts extend from said termination at the deck slab to an adjacent
end surface of the pontoon element.
21. Floating pontoon body according to claim 18, wherein said
terminations of pairs of pulling ducts are arranged in a well in
the deck slab.
22. Floating pontoon body according to claim 21, wherein a well is
arranged at each side of the deck slab, more or less straight above
each side wall wherein the pulling ducts are embedded.
23. Floating pontoon body according to claim 21, wherein the
surfaces of the well where the ends of the pulling ducts are
terminated, are substantially vertical and having a size adapted to
function as support surface for tensioning jacks, intended to be
used for tensioning the cables.
24. Floating pontoon body according to claim 15, wherein the
termination for each pulling duct at each end walls is provided
with a tightening plate, configured in such manner that a
watertight connection is established when the cables are tensioned,
tying together to adjacent pontoon elements.
25. Floating pontoon body according to claim 24, wherein the plate
has a cylindrical shape and wherein the plate is placed inside a
conical recess in the end wall of a pontoon element.
26. Floating breakwater, wherein the breakwater is made up of
pontoon bodies according to claim 15, wherein the breakwater is
made of sections in such way that several pontoon elements are
interconnected to form a curved breakwater where the convex side
faces the main direction of incoming waves.
27. Floating breakwater, according to claim 26, wherein each
pontoon elements have straight side walls, thus forming a straight
body.
28. Floating pontoon body according to claim 15, wherein at least
one dowel is arranged at an end of an adjacent element, intended to
be inserted into a corresponding recess in an adjacent end wall of
an adjacent element, so that the pontoon elements are centred
relative to each other during the connecting phase.
Description
[0001] The present invention relates to a floating pontoon element,
configured to be tied together with at leas one second floating
pontoon element, thereby forming a post-tensioned interconnected
floating body. The pontoon element comprises a deck plate of
concrete and downwards protruding vertical walls of concrete,
thereby forming a hollow floatable body. Along their side wall
edges, said pontoon elements are configured with an upper and lower
pulling tube intended to contain cables or the like, in order to
tie the two or more pontoon elements together both along the upper
and the lower edges of the pontoon elements.
[0002] The invention is in particular suited for establishing
elongate floating bodies, for example intended for use as
breakwaters or floating piers for small boat harbours.
[0003] It has previously been proposed to build floating piers, for
example for small boats, by means of a plurality of separate
pontoon elements which are tied together, forming a large elongate
floating body. It is common practice to connect said various
floating elements together by means of pivotal link, allowing
relative movement between two adjacent, neighbouring floating
bodies. Alternatively, several floating bodies may be tied
together, for example by means of tensioned cables, thereby forming
one post-tensioned, interconnected unit.
[0004] For floating breakwaters it is a requirement of a rigid body
having capacity of stopping the waves, and to a largest extent, to
reduce the wave energy. For such type of structures the floating
body must be as strong and rigid as possible.
[0005] U.S. Pat. No. 3,977,344 describes a floating concrete
structure formed of at least two modules which are tied together by
means of post-tensioned cables, arranged along the upper and lower
side edges of the modules. The floating concrete structure consists
of an elongate main body, formed of module units tied together, and
slipway units tied into the elongate main body in a perpendicular
configuration. The slipway units are also tied to the main body by
mean of post-tensioned cables extending along the upper and lower
side edges of the slipway unit.
[0006] US 20056/0103250 describes a floating unit made up of a
plurality of buoyant bodies tied together by means of
post-tensioned cables, arranged along the upper and lower side
edges of the buoyant body.
[0007] When constructing and assembling floating piers, floating
breakwaters and the like, the dimensions are often based on
existing requirements and demands, and/or adjusted to limited
economical funding. At a later stage, there is often a need of
increasing the capacity and/or the size and dimensions of the
existing, already installed floating pier, breakwater or the
like.
[0008] For piers or the like formed of separate units, linked
together by means of hinges, it is simple to extend or increase the
capacity of the floating pier. In such cases it is only necessary
to attach one or more new elements to the existing unit, which
causes no problems at all. If at a later stage, however, it is
necessary to increase the capacity and/or size of an already
assembled floating pier, breakwaters or the like, formed of
elements tied together by post-tensioned cables, large inherent
limitations exist. In such cases where it is required or necessary
to increase the capacity, etc., the results are often that the
existing floating pier or the floating mole is substituted or
replaced by a completely new breakwater or pier, tailor made for
the new, intended size and/or capacity.
[0009] A further problem to be catered for is the dimensions and
size of each element to be incorporated into the floating body. Due
to economical aspects of road transport of pontoon units from the
production plant to the intended place of use, each pontoon unit
should not have a length exceeding 15-20 m and should further not
have a width exceeding to any degree the width of a trailer or a
lorry.
[0010] An object of the invention is to provide a system which, by
means of a simple method and means, in an economical manner and
based on an existing floating unit, may be adjusted to increased
requirements for capacity and/or size of the floating pier,
breakwaters or the like, without having to substitute the existing
system with a completely new pier or the like.
[0011] Another object of the invention is to provide a flexible
system for assembling floating bodies where capacity increase of
existing floating piers, breakwaters or the like, may be performed
in a simple and economical manner, while said floating bodies are
on site, floating at the sea level.
[0012] A further object of the inventions to provide an assembly
where the risk for cracking of the pulling ducts due to frost, or
corrosion of the post-tensioned cables due to intrusion of sea
water subsequent to the post-tensioning operation, is substantially
reduced.
[0013] A still further object of the invention is to provide an
assembly where it is possible, on a more or less permanent basis in
a physical manner, to prevent intrusion of sea water into the
pulling ducts, thereby avoiding cracking caused by freezing sea
water.
[0014] A still further object of the invention is to provide a
solution where the dimensions of the mooring chains or system may
be optimized without reducing the integrity and safety of the
floating body.
[0015] The objects of the present invention are obtained by a
floating pontoon body as defined in more detail in the
characterizing part of the independent claim, read in context with
the preamble of such claim.
[0016] Further embodiments of the invention are defined by the
dependent claims.
[0017] According to the invention, at least the pulling ducts
extending along the lower side edges of floating element(s) are
configured in such way that it is possible to lengthening the
floating body made up of two or more interconnected pontoon
elements with additional pontoon elements, such lengthening being
performed while the floating pontoon body is in its floating
state.
[0018] According to a preferred embodiment of the invention, said
pulling ducts are terminated at a level above the sea level, at
least at one end. Such arrangement enables the tie-up operation to
be performed above the sea level, such that expensive underwater
works related to tie-up and tensioning of several floating elements
with associated work of divers, may be eliminated.
[0019] From the lower side edge of the pontoon element, the lower
pulling ducts may extend slanted upwards.
[0020] The pulling ducts may optionally have a slight curvature or
may be more or less straight from their lower level towards the sea
level, and the lower pulling ducts are preferably terminated in the
deck plate, the upper end of the pulling duct preferably being
terminated at a distance away from the end wall of the pontoon
element.
[0021] Further, pulling duct may extend from said termination in
the deck slab and outwards towards the free end surface of the
pontoon element, said termination of pairs of pulling ducts in the
deck slab being arranged in a recess or well in the deck slab,
where the surfaces of the well in which the ducts terminates, are
substantially vertical and having a width and height allowing
support for a tensioning jack used to tension the post-tensioned
cables.
[0022] The well may be arranged on each side of the deck slab,
substantially exactly above the side wall wherein the pulling ducts
are arranged.
[0023] Since the pontoon elements are tied together forming a more
or less integrated body, each single pontoon element will to a very
small degree, if at all, move relative to the adjacent,
neighbouring pontoon element. Hence, one tied up integrated body is
thus established. As a consequence, each chain forming the mooring
system of the floating body will more or less take an even share of
the forces induced, i.e. the forces will be evenly distributed
through the various mooring chains. Since cushions or damping
plates are arranged on adjacent surfaces being in contact with each
other, this effect is in particular enhanced by the transition zone
between each pontoon element, at or in relation to the duct/ducts
containing the tensioned cables. Such cushions or damping plates
will provide a certain damping effect, while at the same time they
will prevent crushing of the concrete material in the adjacent wall
sections, and compensate for small relative movements. In addition,
the damping plates will ensure that the point loads are taken by
the four corners of the end surfaces.
[0024] A still substantial advantage according to the present
invention is the possibility of distributing the appearing forces
on cross sections designed to withstand such forces.
[0025] Preferred embodiments of the invention shall be described in
detail below, referring to the accompanying drawings, where:
[0026] FIG. 1 shows a side view of a preferred embodiment of the
invention, where the floating body is formed of three inter-tied
pontoon elements;
[0027] FIG. 2 shows a view seen from above of a start section or a
middle section of the floating body shown in FIG. 1;
[0028] FIG. 3 shows a view seen from above of an end section
according to the invention;
[0029] FIG. 4a shows a vertical section through a start section or
a middle section, see along the line A-A in FIG. 2;
[0030] FIG. 4b shows a vertical section through the end section
according to the invention, seen along the line B-B on FIG. 3;
[0031] FIG. 5a shows an end view of a free end the start section
shown in FIGS. 1 and 2;
[0032] FIG. 5b shows an end view of one middle section and one end
section, alternatively one end of a start section, all intended to
be linked together with the corresponding end of an adjacent
pontoon element;
[0033] FIG. 6 shows schematically a view seen from above of an
alternative embodiment of a breakwater constructed according to the
principles of the invention;
[0034] FIG. 7 shows a section in part of two end surfaces of two
adjacent floating elements, where one of the floating elements is
provided with a protruding dowel, while the opposite floating
element is provided with a corresponding recess; and
[0035] FIG. 8 shows a view of an end surface of the floating
pontoon element.
[0036] FIG. 1 shows a view of a preferred embodiment of a floating
body 10 according to the present invention. As shown in the FIG. 1
three separate units are used. One unit forms a first start section
11, the second unit forms a middle section 12 and a third unit
forms the end section 13, the latter being different compared with
the start section 11 in that it is inverted. In addition, compared
with the start section 11, the end section 13 differs in that the
ends for the tensioning cables are terminated in a well 19 in the
deck slab 15 above sea level, and that the end section further is
configured for tie-in and attachment of a new section.
[0037] Each unit 11,12,13 comprises an upper deck slab 15, pairs of
side walls 16 extending longitudinally of the unit, and two
opposite end walls 16', extending downwards from the deck slab 15
at the end of each section 11,12,13. Each unit 11,12,13 is
downwards open, i.e. they are not provided with a lower bottom. The
units 11,12,13 are further filled with a plurality of polystyrene
blocks 17, arranged side by side, filling out at least parts of the
volume contained inside the vertical walls 16,16' and deck slab
15.
[0038] As shown in FIG. 1, the upper and lower pulling ducts of the
end section 13 are configured in such way that they are terminated
in a well or a recess 19 in the deck slab 15. Upper and lower
pulling ducts extend in longitudinal direction towards the free end
wall 16'. For the embodiment shown in FIGS. 1 and 2, no tensioning
cables are shown installed in the ducts, since said ducts are to be
employed later if a new floating element consisting of one or more
similar sections 11,12,13 is to be added and tied in on the already
established floating body 10.
[0039] If its should prove necessary at a later stage to extend the
floating body, i.e. subsequent to the floating body 10 shown in
FIG. 1 being installed and moored to the operation site, a new
floating section, e.g. formed of a inter-tied unit consisting of
two end sections 13 and an intermediate middle section 12, or a
start section 11, an middle section 12 and an end section 13, is
floated to the referenced site and maneuvered into position with
respect to the installed and moored section end 13 of the floating
body 10. Upper and lower cables are then pulled in from the
arriving unit to be tied in to the existing unit through the yet
unused pulling ducts in the moored end section 13 to the well 19.
The cables are then tensioned, forming a new, extended elongate
floating body 10.
[0040] The free end of the new floating body may correspondingly be
provided with a well 19 and unused pulling ducts installed at the
free end of the moored new end section, still leaving the option at
a later stage of 19 extending the floating body 10 even further, if
considered necessary.
[0041] FIG. 2 shows a view of the floating body 10 shown in FIG. 1,
seen from above. As shown in FIG. 1 the three units 11,12,13 are
tied together by means of tensioned cables 14,14'. The tensioned
cables 14,14' run freely inside the pulling ducts. The pulling
ducts and the tensioned cables 14,14' will be described in further
details below. The space below the deck slab 15, between the deck
slab 15 and the downwards protruding sidewalls 16,16' are filled
with blocks 17 of polystyrene, adding buoyancy and stability to the
floating body 10.
[0042] Further, the floating body 10 is provided with ducts of
channels 21 for the ends of moorings (not shown) or the like, for
example comprising chains extending between the floating body 10
and anchors on the sea bed, thereby providing a safe mooring of the
body 10.
[0043] FIG. 3 shows a view seen from above of an end section 13
according to the invention. As shown in the Figure the end section
13 is provided with two wells 19, arranged on opposite sides of the
end section 13 above the side walls 16. The pulling ducts with
cables 14,14' from the other sections 11,12 are terminated in the
wells 19. Further, pairs of redundant pulling ducts extend from the
wells 19 on each side in the middle part of the section 13 towards
the free end 16' of the referenced section 13.
[0044] FIG. 4a shows a vertical section through a middle section 12
according to the invention, seen along the line A-A in FIG. 2,
while FIG. 4b shows a vertical section through an end section, seen
along the line B-B in FIG. 3. As shown in the Figures a pontoon
body 10 comprises generally a deck slab 15 of concrete and
downwards projecting concrete walls 16 extending along both sides
of the pontoon body 10 and further comprises downwards projecting
end walls 16'. Beads 20 or voutes are provided in the transition
zone between the deck slab 15 and the side walls, including at the
lower edges of the lower, free ends of the side walls. The pulling
ducts 14, through which the post-tensioning cables are intended to
be drawn, are embedded in said beads 20. As indicted in FIG. 4a the
lower beads 20 or voutes on the middle section 12 and along those
parts of the start section 11 and end section 13 being horizontal,
will be placed along the lower, free end of the side walls 16. FIG.
4b indicates that the beads 20 correspond to the curved curvature
of the pulling ducts 16 of the end section 13 and at the one end of
the start section 11.
[0045] FIGS. 5a and 5b shows a view of two different, typical ends
according to the invention. FIG. 5a shows the free end of the start
section 11. As shown in the Figures, the pulling ducts and the
post-tensioning cables are terminated above the sea level, for
example in connection with a plate (not shown) for distribution of
the forces imposed by the post-tensioned cables 14,14' inside the
concrete, said plate also functioning as a support surface for the
end anchors of the post-tensioned cables 14,14'. It should be
appreciated that the start section 11, which optionally is intended
to be moored to one or more mooring points ashore, may be provided
with suitable mooring points (not shown) for such purpose. In
addition or in lieu of said mooring points, the start section 11
may optionally be provided with mooring points 21 corresponding to
the ones shown in connection with the opposite end of the pontoon
element 13.
[0046] FIG. 5b shows another typical end surface 14'. The Figure
shows the shape of the end surfaces 14' of the middle element 12
and the end surfaces 14' of the end element 13. In addition, the
end surface 14' of the start element 11, intended to be tied up
against the end surface 14' of the middle element 12
correspondingly shaped.
[0047] The elements 12,13 intended to be tied up with an existing
floating body 10 must have an end surface 14' which corresponds to
the end surface shown in FIG. 5b. This implies that the adjoining
elements must have a design which corresponds to the end surface of
the middle element 12 and/or the end element 13.
[0048] A substantial advantage of the solution according to the
invention comprises establishing of tight connections at the
transition from the termination end of a pulling duct at one end
wall and the corresponding termination end of the adjoining pulling
duct in the adjacent end wall. A possible solution is to arrange a
plate 18 of a material having, to a certain degree, deformable and
tightening properties, the plate being fixed to one of the end
walls of an element 11,12,13. This implies that when two elements
11,12,13 are tied together, then preferably only a single plate 18
rests against the concrete surface on the adjoining element
11,12,13. Due to the tensioned cables, the elements are pressed
towards each other, forming a tight connection or joint between two
end walls 16'.
[0049] In the Figure, use of rectangular or square plates is
indicated. It should be appreciated, however, that circular plate
having a centrally arranged opening preferably may be used, the
plate preferably being arranged in a conically shaped recess having
a larger outer diameter and a smaller inner diameter. Such shape
caters for possible accumulation of material in the outer part of
the plate, caused by the compression of the plate during tensioning
of the cables. The diameter of the cylindrically shaped plate may
preferably correspond to the inner diameter of the recess.
[0050] FIG. 6 discloses a preferred embodiment where the various
pontoon elements 11,12,13 are connected together in order to form a
breakwater. As indicated in the Figure, each pontoon element is
straight, but may have more or less skewed end surfaces, thereby
forming more or less curved floating body when two or more elements
are tied together. The end walls 16' may preferably be skewed at an
angle in the order of 10.degree. to 30.degree.. The pontoon
elements are tied together in a similar way as described above,
i.e. both along their upper and lower edges and along both
longitudinal sides of the pontoon elements 11,12,13. An
interconnected, tied-in breakwater according to the invention is
moored in such way that the convex side of the breakwater faces
towards the direction from which the waves are coming, ref. the
arrows indicated in FIG. 6. The one or both ends may be formed with
a pontoon element 13, corresponding to pontoon element 13 described
above. According to the embodiment shown in FIG. 6, one end of the
breakwaters may be moored to shore or the like, while the opposite
end of the floating body may be moored to the sea bed by means of a
mooring (not shown). Hence, the breakwaters shown is formed of a
start element 11, a number of intermediate elements 12 and an end
element 13, configured for possible later extensions, such as
described above. It should be appreciated, however, that other
configurations also are possible, without deviating from the
inventive concept.
[0051] FIGS. 7 and 8 show a preferred embodiment of two adjacent
ends of a floating body 10, where one end is provided with at least
one dowel 22 projecting outwards from the end surface and intended
to be inserted into a corresponding recess 23 in the adjacent end
surface on an adjacent element, so that the bodies 10 are centred
with respect to each other in the tie-up phase. In order to secure
a proper centering effect two dowels may preferably be used,
arranged a distance apart.
[0052] Generally, it should be appreciated that the method for
connecting the elements described above is intended to be used for
connecting together two or more pontoon elements, forming for
example piers or moles having a length of for example 300-400 m or
more.
[0053] According to the embodiment shown in the Figures two pulling
ducts are shown along the upper edges of each element and two
pulling ducts are used along the lower edge. It should be
appreciated, however, that a person skilled in the art may, based
on the appearing loads, forces and functions which the pontoon
element is intended to cater for, use a different number and other
configurations of the pulling ducts. This implies that the number
of pulling ducts along the upper edge may differ from the number
used along the lower edge. The same is applicable for the number of
tensioned cables employed.
[0054] According to the solution forming the present invention, it
is possible to tie together a large number of elements and/or add a
large number of elements to existing structures, in order to form
an elongated structure, if deemed required. It is possible, for
example, to use a start element 11, i.e. an element being intended
to be placed close to and moored to shore. Further, a middle
section 12 and an end section 13, tied up with the middle section
12 at one end, may be used, preserving the possibilities of adding
further floating pontoon sections at a later stage.
[0055] The tensioning cables used for tying together the various
floating elements 11,12,13 may be made of steel or of strings or
strands of a composite material, where the load absorbing part may
be made of carbon fibres or of basalt fibres.
* * * * *