A kind of ultra-large type truss-like maritime floating platform
Technical field
The present invention relates to a kind of maritime floating platform, especially a kind of ultra-large type truss-like floating platform.
So-called ultra-large type platform refers to greatlyyer than the span of the macrotype platform of routine, is the platform of radical function so that the large span working space to be provided.As the floating aerodrome, marine comprehensive base etc.
Technical background
One of large-scale unsteady facility of can stablize in wave in the prior art,, surviving in storm is a large ship.It adopts common big waterplane structure, is applicable to the load-carrying navigation.Its problem is that its volume and deadweight sharply increase along with the increase of yardstick, are severely limited on engineering.Its volume is big, drinking water is dark, cause that storm load is big, the drift resistance is big.Use as floating platform, particularly during large, laid down cost is very high, and its mooring or dynamic positioning are costly.
In the prior art, also have semisubmersible platform, as the American about of the patent application of marine tender in China, publication number CN 1269759A.It is with offshore oil semi-submerged platform version large commonly used.Because the body of floating downward of semisubmersible structure is arranged in apart from the water below the horizontal surface certain depth, some small-waterplane-area buoyancy aid (column and diagonal brace, certain buoyancy is provided, make platform have certain attitude stability) protrude upward with the scope of operation and connect, its scope of operation is positioned at the above space of maximum wave height, thereby making the total height of platform from the buoyancy aid to the scope of operation very big, huge and heavy, construction and use cost are very high.The structure of its small-waterplane-area makes platform leave anchoring or dynamic positioning system (DPS) is not easy to accomplish autonomous attitude stabilization, to the load variations sensitivity, thereby has increased the manufacturing cost of ballasting device and has moved complexity.This structure is used for middle-size and small-size platform, and feasibility is economically arranged in the petroleum industry of high production; And be used for the ultra-large type floating structure, and then be difficult to accomplish the reasonableness of efficiency-cost ratio economically, therefore do not put into practice so far.In addition, semi-submerged platform is higher in the state center of gravity that following buoyancy aid emerges, and is only applicable to move boat.
Submercible unit of the prior art is compared with semi-submerged platform, and the water plane area of its column is littler, does not contribute buoyancy basically; System height from its buoyancy aid to the scope of operation is bigger, greater than the depth of water in marine site, place and the wave height sum of highest wave; In order to prevent to be absorbed in silt after buoyancy aid from sitting the end, its buoyancy aid vertical projection area is very big; Move when boat emerging, the platform center of gravity is very high, and this state can not be used for operation, should not be considered as floating platform.
My disclosed patent application PCT/CN03/00304, i.e. the method and the water surface Fixed Point Operation platform of storm load " water surface Fixed Point Operation platform reduce ", but proposed to be suitable for two kinds of submerged platforms of large, wherein a kind of is the untethered dive platform.It has high capacity and becomes buoyant device, in high sea reserve buoyance is reduced to and is no more than 10% of the maximum reserve buoyance of at full load.At this moment the freeboard of platform buoyancy aid is very little, platform is submerged basically, have only the little part of volume to be exposed to more than the water surface, thereby wind load is very little in the high sea, the change of buoyancy distribution is also very little, and this changes caused additional bending moment and additional shear stress load is just very little.This structure really can reduce wave static pressure load, reduces the deadweight of platform structure, makes the platform lightweight.But, because this platform has only by ballast significantly, reduce reserve buoyance, just can enter the free partially surfaced condition that reduces storm load, and high capacity becomes buoyant device and running need be paid certain device cost and use cost, and still may have big wave dynamic pressure load in high sea, the actual reduction of storm load is limited.In addition, this structure is very little owing to reserve buoyance when untethered dive, thereby stability can worsen on the enough not big direction of platform span.As for a kind of controlled submerged platform in this application, then except possessing high capacity change buoyant device, dive (degree of depth) control setup to be set also, increased the complexity of platform structure, made it can not be applicable to the occasion that requires to simplify platform structure, reduces Operating Complexity.Two kinds of submerged platforms are all wanted dive, and untethered dive is dynamic dive, and controlled dive is to continue dive, all will take special measure to the scope of operation, operation facility and manipulating object that should not dive, have also increased the complexity of platform structure.
Put it briefly, in the prior art, the large-scale unsteady facility that can resist high sea has three kinds of typical technologies.One adopts common big waterplane structure, and as large ship, its problem is that volume and deadweight sharply increase along with the increase of span, is severely limited on engineering.It two adopts small-waterplane-area structure, and as semi-submerged platform, its problem is to conduct oneself with dignity greatlyyer, and structure and operation are more complicated, and cost is higher.It three is to adopt latent structure down, and its problem is platform structure and utilization and operation more complicated.This shows that the development of platform technology is wished to explore span large, volume and conducted oneself with dignity the version little, stable when operation, that safety, structure and operation are simple in high sea, wave action power is little, the drift resistance is little.
Summary of the invention
Purpose of the present invention, the i.e. technical matters that will solve, but provide that a kind of span is big, deadweight is little, stable in operating environment, safety, structure and operation are simple in high sea, wave action power is little, the drift resistance is little maritime floating platform version.
Terminological interpretation.Now the part term that the present invention is adopted is explained as follows.
" buoyancy aid " refers to platform is provided the structure of necessary buoyancy.So-called necessary buoyancy refers to keep platform bearer ability and the needed buoyancy of normal stability.Need to prove that the structures such as upwardly extending pitman that this platform has though have certain volume, have certain displacement when immersing in the water, its buoyancy is also inessential to keeping platform bearer ability and normal stability, thereby does not regard buoyancy aid as.As a comparison, upwardly extending structures such as the column of the seabase of semi-submerged platform and aforementioned patent document 759, diagonal brace must have certain volume and water plane area, and necessary buoyancy is provided, and just can make platform have the stability of requirement.So they have the function of buoyancy aid in fact, in notion of the present invention, regard the part of buoyancy aid as.
" scope of operation " refers to the driving surface that the platform operation is required, as deck, Working cabin, equipment attachment face etc.Alleged " operation at sea face " refers to not allow in the high sea away from the water surface, under normal condition the scope of operation of being touched by wave.
" pitman " can be solid or hollow bar.Pitman be used between the buoyancy aid and buoyancy aid and scope of operation structure between connect, make it to become the single-piece truss structure.
" integral rigidity " of platform structure refers to not have relative motion between the main platform body each several part, but do not get rid of the infinitesimal deformation that solid material produces when stand under load.So-called " truss structure " refers to the structure is made up of rod member, is the version that the large scale structure is used always.All or part of of this flat-bed buoyancy aid, operation at sea face and pitman all can be considered as the rod member of truss.The rod member of truss mainly bears longitudinal pulling force and pressure.The deadweight of a certain rod member of truss structure is little usually to the flexure stress that this rod member itself produces.But the rod member that this platform is made of buoyancy aid is under buoyancy, and the rod member that is made of the scope of operation (as deck construction) may produce the flexure stress of can not ignore under the operating load effect, and these rod members have the character of beam simultaneously concurrently.But these situations do not hinder the present invention this platform to be called on the whole " truss structure ".
" maximum wave height " promptly designs wave height, the maximum wave height that the selected several years one meet when referring to platform design.Panel height is a wave height half.
Technical scheme.In order to solve the problems of the technologies described above, the technical scheme that the present invention proposes is:
1) this platform has buoyancy aid, operation at sea face and pitman, and buoyancy aid is positioned at the platform bottom, and the operation at sea face is positioned at platform top, and buoyancy aid, operation at sea face and pitman connect mutually, forms the truss structure of integral rigidity;
2) cumulative volume of buoyancy aid is not more than about 2 times of equivalent water volume of platform at full load full weight;
3) buoyancy aid is a cylindrical shape, and diameter is not more than about 1/4 of maximum wave height;
4) buoyancy aid is arranged on the plane of horizontal direction, arrangement in parallel at least one direction, and adjacent buoyancy aid spacing is not more than maximum wave height approximately, 1.5 times of not little buoyancy aid diameter approximately; The length of distribution space is not less than about 8 times of maximum wave height, and width is not less than about 1.5 times of maximum wave height;
5) the water plane area sum of buoyancy aid be not more than the projection on horizontal surface of buoyancy aid profile the envelope region area about 50%.
The technical meaning of abovementioned technology of the present invention is described as follows.
A. this platform has the sizable truss-like overall structure of span.
Buoyancy aid, operation at sea face and pitman are connected into the truss of integral rigidity mutually.Buoyancy aid distribution limit length in the horizontal direction is not less than about 8 times of maximum wave height, and width is not less than about 1.5 times of maximum wave height.If maximum wave height is set at 30 meters, then distribution length is not less than about 240 meters, and width is not less than about 45 meters, so span is quite big.
B. limit the cumulative volume of platform buoyancy aid, reserve buoyance and floating line position.
The cumulative volume that defines buoyancy aid is not more than about 2 times of equivalent water volume of platform at full load full weight, therefore, the platform at full load, the reserve buoyance of buoyancy aid is not more than 1 times of full weight.Floating line is in the buoyancy aid altitude range.If reserve buoyance is about 1 times of the platform full weight, then obviously floating line is highly located at buoyancy aid about 1/2.
C. the cumulative volume of buoyancy aid is dispersed on the less cylindrical shape buoyancy aid of a plurality of volumes.
Limit the cylindrical shape that is shaped as of buoyancy aid, its diameter is not more than about 1/4 of maximum wave height.Usually maximum wave height is about 30 meters, thereby the buoyancy aid diameter is not more than about 7.5 meters.The buoyancy aid diameter is little, and the volume of each buoyancy aid is just less, thereby buoyancy aid should have certain total length and quantity, just can have certain cumulative volume.
D. the less buoyancy aid of diameter is pressed on the large-area in the horizontal direction plane of less spacing dispersed placement, the platform shallow draft, and the water surface dutycycle of buoyancy aid is little.
The less buoyancy aid of diameter is distributed on the plane of the horizontal direction that the direction span is very big in length and breadth, and the buoyancy aid diameter is not more than about 1/4 of maximum wave height.Static floating line is in the buoyancy aid altitude range, so the platform drinking water is very shallow.
Adjacent buoyancy aid spacing is not more than maximum wave height (for example 30 meters) approximately, is not less than 1.5 times of buoyancy aid diameter approximately.Therefore, buoyancy aid is dispersed placement on the whole.
The water plane area sum of buoyancy aid is not more than envelope region area about 50% of buoyancy aid profile projection on horizontal surface, and promptly water surface dutycycle is little.
Briefly, flat-bed overall structure of the present invention is a large-span truss, its underpart is the small diameter cylinder shape buoyancy aid of large span, little spacing arrangement on horizontal surface, and the buoyancy of buoyancy aid props up platform and is held in the water surface, and its operation at sea face is more than the height that highest wave can not touch.
Basic beneficial effect of the present invention can be described as follows.
It is cylindrical shape that the present invention limits buoyancy aid, and its diameter is very little with respect to maximum wave height.The cylindrical shape buoyancy aid helps that the wave dynamic pressure of all directions is all had the less resistance coefficient, and tubular construction makes buoyancy aid become the rod member of truss easily, and has strut stability preferably as the rod member of truss, and flexing resistance is preferably arranged when it has the character of beam concurrently.
The upper limit that the present invention limits platform buoyancy aid reserve buoyance only is 1 times of fully loaded full weight.The buoyancy aid cumulative volume is little, and is dispersed into the buoyancy aid of more minor diameter, helps reducing wave to the flat-bed applied loading.In the unsteady facility of general prior art, reserve buoyance is not easy to satisfy the stability requirement for a short time.But flat-bed buoyancy aid span of the present invention is very big, and water plane area is big relatively, although reserve buoyance is little, the buoyancy aid freeboard is very little, still can provide enough moment of stability.
When the wave height of wave was significantly less than tubular buoyancy aid diameter, tubular buoyancy aid distribution length can be crossed over a plurality of wavelength usually, and had a plurality of tubular buoyancy aids arranged side by side on Width.Numerous waves are cancelled each other to the flat-bed application force, so platform obviously keeps good attitude stability easily.Referring to Figure 11 A and Figure 12 A.
For more long narrow platform, make the flat-bed length direction point to the wave working direction in use usually.Referring to planar view 11A.At this moment, platform is original just little waving of Width.When wavelength direction and the land lengths direction harsh situation of quadrature substantially, the incidental Figure 11 of not being B crest line of wave is straight but be the situation of crest line of wave bending shown in Figure 11 C.Therefore, the buoyancy change that the wave static pressure causes and the dynamic pressure effect of wave mainly make platform bear moment of torsion, and the big feature of platform longitudinal length helps cancelling each other of many places moment of torsion, thereby help reducing lateral oscillation.
Under worst situation shown in Figure 11 B, the platform buoyancy aid dispersion of distribution then of the present invention is not less than 1.5 times of maximum wave heights, thereby laterally also has necessary stability easily.
When wave height surpasses tubular buoyancy aid diameter, see Figure 12 B and 12C signal.As long as platform and integrally still can stride two above wavelength, with taking place, crest upwards crosses the situation that buoyancy aid or trough break away from buoyancy aid downwards, even some part of buoyancy aid is flooded by wave, some part breaks away from water surface, platform still keeps attitude stability preferably.Dash area a is the part that crest is upwards crossed buoyancy aid among Figure 12 C, and dash area b is the part that trough breaks away from buoyancy aid downwards.Long and two-short dash line c represents that wave height is bigger, crest makes progress the situations of crossing the more disengaging buoyancy aids of buoyancy aid, trough downwards more among Figure 12 C.Above characteristics have the present invention can keep stable holding property of motion in wave.
Platform of the present invention has less, a fairly large number of another beneficial effect of buoyancy aid diameter, when big wave occurring, the part of being flooded by wave in the buoyancy aid suffered wave force general no longer increase with the increase of wave height, the part buoyancy aid that breaks away from the water surface will not bear wave force, therefore, after wave height surpassed certain value, the suffered wave load of buoyancy aid each several part was insensitive to the wave height increment more than the certain limit, thereby helped reducing the upper limit of suffered application force.In addition, suffered power can partly be cancelled each other between some part of buoyancy aid.These situations help reducing and disperse wave to whole flat-bed application force, reduce wave load to the flat-bed destructive effect, improve the safety of platform structure in the high sea, thereby in general help the lightweight of platform structure.
The drinking water of this platform is very shallow, thereby has advantages such as suitable marine site condition restriction is few.
This platform dutycycle on the water surface is little, and therefore, though have super-span, the envelope zone that takies the water surface is very big, have only the Wave energy of smaller portions to act on platform in this zone, thereby the wave action that platform is born is less.
In a word, platform of the present invention can have the very scope of operation of not touched by billow of large span, can make the volume of platform buoyancy aid again and little, the wave of conducting oneself with dignity to the flat-bed applied loading little and dispersion, shallow draft, the drift resistance is little, platform is stable when operation, in high sea safety, structure and operation simpler, thereby reduce flat-bed manufacturing cost and operating cost.
Be noted that in the above-mentioned beneficial effect of this flat-bed, have the enlarge-effect of beneficial effect.For example, caused deadweight to reduce by some technical characterictics, it helps reducing the buoyancy aid volume, reduce wave action power reduces, reduces requirement of strength, thereby causes conversely further reducing conducting oneself with dignity.Similarly, deadweight causes force of inertia to reduce for a short time, also helps reducing the flat-bed requirement of strength, also causes further reducing deadweight conversely.Enlarge-effect makes this flat-bed beneficial effect more obvious.
Description of drawings
Fig. 1. embodiment 1 platform general picture.
Fig. 2. the signal of embodiment 1 platform cross-sectional plane
Fig. 3. embodiment 1 platform side-looking.
Fig. 4. the local signal of embodiment 1 flat-bed hollow out first structure.
Fig. 5. the signal of embodiment 1 flat-bed hollow out deck construction, the A-A view of Fig. 4.
The signal that Fig. 6 A and 6B. embodiment 1 platform are made up of less platform unit.
Many platforms of Fig. 7 A and 7B. are formed more large span flat-bed signal.
Fig. 8. embodiment 2 platform birds-eye vieies, part illustrate the buoyancy aid of below, deck.
Fig. 9. embodiment 2 platform front elevations, the K-K view of Fig. 8.
Figure 10. the dutycycle of embodiment 1 platform buoyancy aid on the water surface.
The state of Figure 11 A, B and C. platform of the present invention in wave overlooked signal.
The state of Figure 12 A and B. platform of the present invention in wave, the side-looking signal.
The state of Figure 12 C. platform of the present invention in wave, the side-looking signal, the I portion of Figure 11 B amplifies.
Below in conjunction with the description of drawings embodiments of the present invention.
Embodiment
Example 1
Fig. 1, a kind of large-span truss formula maritime floating platform 1 of 2 and 3 expressions, its designed use is marine floating aerodrome.The maximum wave of platform design extreme environment is 28 meters of wave height, is 14 meters of panel heights.But operating environment is 6 grades of sea situations, about 6 meters of its upper limit wave height.
This platform 1 has buoyancy aid 2, pitman 3, the upper strata flight deck 4 that 4 arrangement in parallels are positioned at the water surface.Buoyancy aid 2 also is the rod member of truss simultaneously.Platform deck length is that 300 meters, width are 60 meters.
Buoyancy aid, operation at sea face and pitman connect mutually, form the truss structure of integral rigidity, therefore meet aforementioned techniques measure 1 in the technical solution of the present invention) requirement.
It below is the basic specification of platform structure.
4 buoyancy aids 2 are cylindric, 4 meters of diameters, long 300 meters.Near between the floating drum shown in Figure 2 the water surface horizontal pitman 3a has the polyline shaped of central K/UP, helps suitably avoiding wave.
About 9500 tons of the fully loaded full weight of platform.About 3800 cubic meters of single buoyancy aid volume, 4 buoyancy aids add up to about 15200 cubic meters of cumulative volume, are 1.6 times of fully loaded about 9500 cubic meters of full weight.Floating line 5 near buoyancy aid height 60% (high 2.4 meters), about 1.6 meters of buoyancy aid freeboard.
About 15 meters of the structure lower edges of flight deck 4 apart from the upper edge of buoyancy aid 2, about 16.6 meters apart from floating line, greater than maximum panel height.The position height of operation at sea face has guaranteed that wave does not touch the scope of operation in storm, does not make the platform excessive overall height simultaneously again.The intensity that truss structure in this clearance space only provides platform to need needn't provide other reserve buoyance for flat-bed is stable, and its volume should be as far as possible little, and its configuration should make every effort to make platform to reduce the total amount of windage wave resistance.
Because the width of this platform buoyancy aid distribution space is greater than 1.5 times of maximum wave height, so scope of operation height makes height less than 2/3 of width less than maximum wave height, for platform in storm not turning over good condition is provided.
4 cylindrical shape buoyancy aids are arranged in parallel on the plane in the horizontal direction, and adjacent buoyancy aid width between centers angles 15 meters; Buoyancy aid distribution space length is 300 meters; Width is 49 meters.Because 4 buoyancy aid arrangement in parallels, absorb water very shallowly, longitudinal resistance is little, helps mooring and prevents floating and moving boat.
4 buoyancy aids 2 of shown in Figure 10 flat-bed.Its projection envelope zone is a rectangle, and the about .A of rectangle, B, C, 4 of D are the summit, and the envelope region area is 300 * 49 about 15000 sq ms.Each buoyancy aid water plane area sum is 4 * 4 * 300=4800 sq m, dutycycle less than 15000 50%.
This platform has 6 horizontal omnidirectional propelling units 7 that can make the anti-drift of platform and platform can independently be navigated by water, and sees Fig. 2 and 10 signals.
In order to prevent the damage water inlet, filling with light material 6 in the space below the inherent floating line height of this platform buoyancy aid sees that Fig. 2 illustrates.
Because this platform deck area is very big, will produce huge air lift force load in storm.At this type of situation, the present invention proposes to adopt the hollow out deck.This deck adopts the prior art in construction steel structure field shown in Fig. 4 and 5, its structure 10 is by 5 millimeters thick, steel plate bar 11 parallel longitudinals of 30 mm wides are arranged, the Width of lath is a vertical direction, there is steel bar 12 to be connected into grid up and down, forms open texture, 30 millimeters of the square hole length of sides, 35 millimeters of hole width between centerss, the hollow out rate reaches 73%.Usually, the hollow out rate is not less than 50% just can have the effect that significantly reduces lift load.
For platform construction makes things convenient for, and become other shapes, or in order to move needs such as convenient, this platform can be formed by less platform unit splicing-in for the ease of splicing-in.For example, can be that 150 meters, wide 60 meters less platform unit 1a and 1b connect and form by 2 deck length, see Fig. 6 A.And for example, if this platform deck is wide 90 meters, see Fig. 6 B platform 1 ', its tubular buoyancy aid 2 ' has 6, and 15 meters of spacings then can be formed by less platform unit 1 ' a, 1 ' b, 1 ' c, 1 ' d, 1 ' e and 1 ' f connection.100 meters of the wide length in the deck of each platform unit, wide 45 meters, have the cylindrical shape buoyancy aid of 3 arrangement in parallels.
Because only 300 meters of present embodiment land lengths can only be fit to vertical take-off and landing aircraft (VTOL aircraft) and the only a few STOL aircraft takes off, land and also need block equipment.The platform of 300 meters of a plurality of length can be connected to each other for this reason, can form longer and have difform runway and hardstand,, see Fig. 7 A and 7B to adapt to various conventional airplane Normal Take-Off And Landings.
Platform connects with flat-bed as mentioned above, in the occasion of not preparing to reequip, can be welding; In the occasion of preparing repacking, can be general removable connections such as bolt, maybe can be special fast assembling-disassembling connects.U.S. Pat 5988932 discloses the structure that a kind of fast assembling-disassembling connects, can be for reference.When adopting removable connection or fast assembling-disassembling to connect, three point of attachments should be arranged at least on each conjunction plane of flat-bed, make connecting relation have integral rigidity.Simultaneously, in order in connection process, to be convenient to two platforms slowly to be drawn close and point of attachment is aimed at easily, two rope chain haulage devices should be arranged at least on each conjunction plane.In actual join operation, when draw gear is drawn close two platforms, the inertial collision when external force effect restriction butt joint also should be arranged.For example, when platform has all direction propeller, can push away with propelling unit is counter, traction furthers, and prevents collision.
A part of technical equipment of homeplate such as navigational aid, communication apparatus and logistics cabin can be arranged on other boats and ships, or directly utilize the supporting use of existing equipment of other boats and ships, and this will have more economy.Therefore, can need not on the platform to dispose too much complicated technology equipment and a large amount of personnel, the laid down cost of homeplate and technical risk will reduce greatly.
Model to above-mentioned basic specification has carried out finite element analysis: the buoyancy aid wall thickness of this model is 15 millimeters; 0.8 meter of part pitman diameter, 10 millimeters of wall thickness; 2 meters of part diameters, 20 millimeters of wall thickness, center of gravity is high 8.701 meters, one 0.9426 meters of height of center of buoyancies, moment of inertia Ixx=3.5215E+6 (ton rice
2, down together), moment of inertia Iyy=6.0068E+7, moment of inertia Izz=6.1197E+7.
1. to the motion response and the drift force of wave.
But get operating environment is 6 grades of sea situation upper limits, wave height 6.0, cycle 5-10 second.
Motion response significant valve (1/3 value) is surging 0.78 (rice, down together) to the maximum, and swaying 2.29 is hung down and swung 2.38; 1.13 ° of pitchings, 1.5 ° of rolling, 0.84 ° of yawing.
The maximum significant valve of average drift power (1/3 value) is vertical 18.1 tons to the maximum, and horizontal 214.3 tons, 3039 tons of rice of yawing moment.
These data show that this routine structure is quite little to the motion response and the drift force numerical value of wave.
2. the stress of wave load.
Get trochoidal wave, 300 meters of wavelength, wave height 4-10 rice.Calculating shows that vertical moment of flexure and shearing are insensitive to the wave height response.This has illustrated a key property of this routine structure, and promptly wave height increases to the certain numerical value after load and do not increase with the continuation of wave height.According to result of calculation, get million Ns of rice of vertical moment M vmax=1300, million Ns of shearing Nvmax=15.7, million Ns of rice of moment of torsion Mt=440.
The results, during million Ns of rice of the vertical moment M vmax=1300 of applied load, each position stress level is not high, and within normal allowed band now, only some top pitman stress up 245 MPa is not difficult to be solved by structure optimization; When applying million Ns of rice of moment of torsion Mt=440, structure maximum shear stress 62 MPas are within normal allowed band now.
Example 2
Fig. 8 represents that this example 2 platforms have square deck 4 ', and 240 meters of the length of sides have the smooth deck of large tracts of land, and designed use is marine comprehensive base, has the ability of the large-scale captive balloon of folding and unfolding.The maximum wave of platform design extreme environment is 28 meters of wave height.But operating environment is 8 meters of wave height.
3.2 meters of tubular buoyancy aid 2 ' diameters, each 16 in length and breadth, quadrature arrangement is at grid intersection point p
1, p
2The place is passed through mutually, and lattice are apart from being 15 meters in length and breadth.About 59000 cubic meters of buoyancy aid cumulative volume, about 35000 tons of the fully loaded full weight of platform, the floating line height is about buoyancy aid diameter 60% (1.85 meters).The spacing of this platform deck structure lower edge to buoyancy aid upper edge is burnt 15 meters.
Whole platform is made up of 4 square shaped cells.Deck 4 ' a, the 4 ' b of each unit, the length of side of 4 ' c, 4 ' d are 120 meters.It between the unit removable connection.
This platform is compared with example 1, because width increases, full line platform contingent moment of flexure in cross-sectional plane increases, thereby increases the material deadweight increase of bar with the requirement of strength of the corresponding transverse bar member of example 1 horizontal pitman 3a.The horizontal pitman 3a that replaces now example 1 with horizontal floating drum 2a makes horizontal floating drum and vertically floating drum is identical, all has concurrently to produce buoyancy and dual-use function as pitman, and the increase of material effectiveness helps the light in structure quantification.Simultaneously, the buoyancy aid diameter is littler, and buoyancy distribution is disperseed more, according to the reason to setting forth in the technical scheme explanation, comprises cancelling each other and reducing the transmission distance of power of dispersancy, also helps light in structure and quantizes.
The detail that various embodiments of the present invention are described does not have restriction to the technical measures of invention.