CN110397068A - A multi-tube steel-concrete composite foundation structure and its construction method - Google Patents

Abstract

The invention belongs to the technical field of foundation structures of marine engineering, and discloses a multi-tube steel-concrete composite foundation structure and a construction method thereof, comprising a plurality of steel cylinder foundations whose center points are connected to form a regular polygon, and a steel roof connected to the upper parts of the plurality of steel cylinder foundations. A concrete slab is set on the steel roof, and an outer ring beam, a middle ring beam, an inner ring beam, a concrete main beam, and a concrete secondary beam are set on the top surface of the concrete slab, and the upper part of the middle ring beam is connected to the concrete transition section, and the upper part of the concrete transition section is set with a steel tower; The construction method includes steps such as land prefabrication, shore hoisting, water towing, negative pressure sinking, and negative pressure reinforcement. The invention has the advantages of gravity foundation and cylinder foundation, wide application range, convenient transportation and installation, recyclable utilization and high bearing capacity. The upper fan load is converted into structurally controllable tension and compression stress, which can also be used as a gravity structure to resist the upper load through its own gravity.

Description

A multi-tube steel-concrete composite foundation structure and its construction method

technical field

The invention relates to the technical field of foundation structure of marine engineering, in particular to a multi-tube composite foundation structure and a construction method thereof.

Background technique

At present, in the field of offshore wind power, the forms of wind turbine foundations mainly include gravity foundations, jacket foundations, barrel foundations, pile foundations, floating foundations, etc.

The gravity foundation relies on the weight of the structure and the weight of the filler and ballast on it to resist external loads and maintain structural stability. The construction principle is simple, the cost of filler and ballast materials is low, and the construction cost is relatively low for shallow foundations; but the foundation The self-weight and geometric size are large, the foundation occupies a wide range of seabed, and has high requirements on geological conditions. Therefore, the gravity-type foundation is applicable to a limited range of water depth and high cost. The suction-type tubular foundation has simple form, strong bearing capacity, simple transportation and installation, easy recycling, and high stability of the tubular skirt against slipping. However, as the water depth increases, the wind, wave and current loads become larger, and the diameter of the cylindrical foundation required for large bending moment loads is larger, and large-scale equipment is required for transportation and installation.

Contents of the invention

The present invention focuses on solving the technical problems of unreasonable load transfer, complex construction and installation, and difficult leveling of multi-tube foundations in the current offshore foundation structure. It provides a multi-tube steel-concrete composite foundation structure and its construction method, which combines the cost Low, strong bearing capacity, easy installation, low cost, and recyclable characteristics of cylindrical foundation, high bearing capacity, convenient installation and transportation, wide application range, and greatly reduced cost.

In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

A multi-tube steel-concrete composite foundation structure, including multiple identical steel tube foundations, the multiple steel tube foundations can be arranged on the horizontal plane to form a regular polygon according to the line connecting their center points, and the multiple steel tube foundations The top of the foundation is jointly connected with a steel roof, and a concrete slab is arranged on the top of the steel roof; a circular through hole is opened in the center of the steel roof and the center of the concrete slab, and the circular through hole is connected with the steel cylinder foundation The projections of the steel roof and the concrete slab do not intersect; the concrete transition section is provided on the upper part of the concrete slab, and the concrete transition section is a linear thin-walled structure with a ring section, and the diameter of the bottom ring is larger than the top circle ring diameter; the upper part of the concrete transition section is provided with a steel tower, and the bottom of the steel tower is embedded inside the concrete transition section;

The top surface of the concrete slab is provided with an outer ring beam, a middle ring beam, and an inner ring beam; the outer ring beam is located at the outer edge of the top surface of the concrete slab; the middle ring beam is located at the middle of the top surface of the concrete slab, and arranged at the lower part of the concrete transition section; the inner ring beam is arranged at the edge of the circular through hole on the top surface of the concrete slab;

Concrete main beams are evenly arranged radially on the top surface of the concrete slab, and the concrete main beams extend from the inner ring beam to the outer ring beam; Concrete secondary beams are evenly arranged radially between the main beams, and the concrete secondary beams extend from the middle ring beam to the outer ring beam.

Further, the number of the steel cylinder foundations is 3-6; the radius of the steel cylinder foundations is 10-15m, and the height is 8-12m; the net distance between two adjacent steel cylinder foundations is the steel cylinder foundation 1-3 times the outer diameter of the base of the cylinder.

Further, upward steel ribs are provided on the periphery of the steel roof, and the steel ribs are inserted into the concrete slab and the outer ring beam.

Further, the concrete slab is consistent with the outline of the steel roof, and the thickness of the concrete slab is 0.3-1m.

Further, the radii of the center of the steel roof and the circular through hole of the concrete slab are both 0.5-1.0 times the radius of the steel cylinder foundation 1 .

Further, the concrete transition section is a constant-thickness structure with a wall thickness of 0.5-1.5m and prestressed steel strands distributed in the middle.

Further, the outer edge of the outer ring beam is flush with the outer edge of the concrete slab, and the shape is consistent with the edge of the concrete slab; the width of the outer ring beam is 0.5-1.5m, and the height is 0.8-1.8m m; the middle ring beam is located in the middle of the top surface of the concrete slab, in the shape of a ring, with a width of 0.5-1.5m and a height of 0.8-1.8m; the radius of the middle ring beam is the radius of the steel tower 1.5-2 times; the inner diameter of the inner ring beam is consistent with the diameter of the circular through hole, the width is 0.5-1.5m, and the height is 0.8-1.8m.

Further, the width of the concrete main beam is 0.5-1.5m, and the height is 0.8-1.8m; the angle between adjacent concrete main beams is 60 degrees; the concrete secondary beams include 12-18, 2-3 concrete secondary beams are arranged between every two adjacent concrete main beams, and the included angle between the axes of adjacent concrete secondary beams is 20-30 degrees.

Further, the steel tower is a steel pipe with variable cross-section and equal thickness, and the bottom diameter is larger than the top diameter.

A construction method for the above-mentioned multi-tube steel-concrete composite foundation structure is carried out according to the following steps:

(1) prefabricating a plurality of steel cylinder foundations on land, and arranging the plurality of steel cylinder foundations on the horizontal plane according to the line connecting their center points to form a regular polygon, and then welding with the steel roof;

(2) Using the steel roof as the bottom formwork of the concrete slab, binding steel bars on the steel roof, the concrete slab, the outer ring beam, the middle ring beam, the inner ring beam, the The concrete main beam, the concrete secondary beam and the concrete transition section are poured together;

(3) hoist the overall structure completed by the above pouring construction into the water, check the air tightness, install the steel tower on the concrete transition section, and install the machine head on the steel tower, according to the towing Adjust the draft of the steel cylinder foundation according to navigation requirements;

(4) carrying out floating towage with described multi-barrel steel-concrete combination foundation structure and described nose;

(5) After the multi-barrel steel-concrete composite foundation structure and the nose are floated and towed to the designated sea area, first sink by self-weight, and then sink to the designated position under negative pressure;

(6) After the subsidence is completed, the soil inside the steel cylinder foundation is reinforced.

The beneficial effects of the present invention are:

In the multi-tube steel-concrete composite foundation structure of the present invention, a plurality of single-tube foundations are connected into a whole through the steel roof and the concrete slab, which is beneficial to increase the anti-overturning moment of the multi-tube steel-concrete composite foundation structure and improve the stability during transportation; the concrete The combination of slab and slab beam system effectively transmits and evenly disperses the upper load, which is approximately converted into tension and pressure at the cylindrical foundation to maximize the bearing capacity of the cylindrical foundation. The structural stress system is clear; the concrete transition section adopts cast-in-place The technology is an integral structure, which jointly transmits the upper load, increases the overall rigidity of the structure, saves materials, and reduces the cost. The multi-steel cylinder steel-concrete composite foundation structure, the rigidity of the steel roof is large, and the inclination angle during the foundation sinking process can be adjusted by adjusting the pressure between the steel cylinders. The high rigidity is conducive to the smooth leveling of the foundation.

In the multi-tube steel-concrete composite foundation structure of the present invention, the connection between the steel roof, the concrete slab and the concrete transition section enhances the integrity of the multiple steel tube foundations, and can effectively improve the mutual displacement between the steel tube foundations during the construction process, etc. conditions, it is beneficial to improve the construction quality, and at the same time avoid the excessive difference in internal force between the steel cylinder foundations, thereby reducing the overall uneven settlement of the multi-tube steel-concrete composite foundation structure, and the setting of the circular through hole in the middle of the steel roof and the concrete slab reduces the The sinking resistance of multiple steel cylinder foundations in water is convenient for construction.

To sum up, the multi-tube steel-concrete composite foundation structure of the present invention has the advantages of gravity foundation and cylindrical foundation, wide application range, convenient transportation and installation, recyclable utilization, high bearing capacity, and can be used as a top-supported structure. The steel tower and the linear transition section convert the upper fan load into structurally controllable tensile and compressive stress, and can also be used as a gravity structure to resist the upper load through its own gravity.

The multi-tube steel-concrete composite foundation structure of the present invention can realize the technology of "prefabrication on land - floatation - towage - sinking - leveling" during construction, the pouring quality is reliable, there is no impact load such as piling, and the construction process avoids The use of large machinery such as lifting equipment at sea reduces the construction process, reduces the difficulty of offshore operations and the risk of damage to wind turbines due to rapid and harsh changes in the marine environment, the required equipment is simple, safe and effective, and the offshore installation time only takes a few hours , Compared with the traditional infrastructure construction period is short, high efficiency, good quality, high safety, greatly reduce the cost of offshore wind power construction and wind turbine installation.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram of multi-tube steel-concrete composite foundation structure provided by the present invention;

Fig. 2 is the front view of the multi-tube steel-concrete composite foundation structure provided by the present invention;

Fig. 3 is the plan view of multi-barrel steel-concrete combined foundation structure provided by the present invention;

Fig. 4 is a structural schematic diagram of the reinforced concrete beam-slab system in the multi-tube steel-concrete composite foundation structure provided by the present invention.

In the figure: 1. Steel cylinder foundation; 2. Steel roof; 3. Concrete slab; 4. Outer ring beam; 5. Middle ring beam; 6. Inner ring beam; 7. Concrete main beam; 8. Concrete secondary beam; 9. Concrete transition section; 10. Steel tower.

Detailed ways

In order to further understand the invention content, characteristics and effects of the present invention, the following examples are given, and detailed descriptions are as follows in conjunction with the accompanying drawings:

As shown in Figures 1 to 3, this embodiment discloses a multi-tube steel-concrete composite foundation structure, including multiple identical steel tube foundations 1, steel roof 2, concrete slab 3, outer ring beam 4, and middle ring beam 5 , inner ring beam 6, concrete main beam 7, concrete secondary beam 8, concrete transition section 9, steel tower tube 10.

A plurality of identical steel cylinder foundations 1 are independent of each other, arranged in a horizontal plane according to the line connecting their center points to form a regular polygon, and are welded together with the steel top plate 2 at the upper part. The number of steel cylinder foundations 1 is generally 3-6; the steel cylinder foundation 1 is a steel cylindrical structure with a radius of 10-15m and a height of 8-12m. The clear distance between two adjacent steel cylinder foundations 1 is 1-3 times the outer diameter of the steel cylinder foundations 1 .

The steel top plate 2 is arranged on the top of multiple steel cylinder foundations 1 and welded to the top surface of the steel cylinder foundations 1 . The shape of the steel top plate 2 is surrounded by the outer common tangent of the section circle of the adjacent steel cylinder foundation 1 and the arc line segment between the outer common tangent lines, and the projection of the center of each arc line segment is on the horizontal plane above for the same point. The thickness of the steel top plate 2 is 0.006-0.01m. An upward steel rib plate is arranged on the periphery of the steel roof 2, and the height of the steel rib plate is the same as the total height of the concrete slab 3 and the outer ring beam 4; the steel rib plate is used to be inserted into the concrete slab 3 and the outer ring beam In step 4, the effective connection between the concrete structure and the plurality of steel cylinder foundations 1 as a whole is realized. There is a circular through hole in the center of the steel top plate 2, which is used to reduce the sinking resistance of multiple steel cylinder foundations 1 in water; the scope of the circular through hole does not extend to the position of the steel cylinder foundation 1, that is, the circular through hole It does not intersect with the projection of the steel cylinder foundation 1 on the steel roof 2 , and the radius of the circular through hole in the center of the steel roof 2 is generally 0.5-1.0 times the radius of the steel cylinder foundation 1 .

The upper part of the steel roof 2 is provided with a concrete slab 3, the concrete slab 3 is consistent with the outline of the steel roof 2, and the thickness of the concrete slab is 0.3-1m. The concrete slab 3 is poured on the upper part of the steel roof 2, and the steel ribs of the steel roof 2 go deep into the concrete slab 3, so that the concrete slab 3 and the steel roof 2 are firmly combined. A circular through hole is also opened in the center of the concrete slab 3, and the radius of the circular through hole is consistent with the size of the circular through hole on the steel roof 2, which is also used to reduce the sinking of multiple steel cylinder foundations 1 in water resistance.

As shown in FIG. 4 , three ring beams are arranged on the top surface of the concrete slab 3 , including an outer ring beam 4 , a middle ring beam 5 , and an inner ring beam 6 . The outer ring beam 4 is located outside the top surface of the concrete slab 3, its outer edge is flush with the outer edge of the concrete slab 3, and its shape is consistent with the edge of the concrete slab 3; the outer ring beam 4 has a width of 0.5-1.5m and a height of 0.8-1.8 m. The middle ring beam 5 is located in the middle of the top surface of the concrete slab 3 and is circular in shape with a width of 0.5-1.5m and a height of 0.8-1.8m; the radius of the middle ring beam 5 is 1.5-2 times the radius of the steel tower 11. The inner ring beam 7 is arranged at the edge of the circular through hole on the top surface of the concrete slab 3, the inner diameter of the inner ring beam 7 is consistent with the diameter of the circular through hole, the width is 0.5-1.5m, and the height is 0.8-1.8m.

The top surface of the concrete slab 3 is connected with a concrete main beam 7 and a concrete secondary beam 8 between the three ring beams. The concrete main beam 7 is evenly arranged radially on the top surface of the concrete slab 3 and extends from the inner ring beam 7 to the outer ring beam 4 . In one embodiment of the present invention, the concrete main beams 7 include six, and the angle between adjacent concrete main beams 7 is 60 degrees; the width of the concrete main beams 7 is 0.5-1.5m, and the height is 0.8-1.8m m. Concrete secondary beams 8 are evenly arranged radially between every two adjacent concrete main beams 7 on the top surface of concrete slab 3 , extending from middle ring beam 5 to outer ring beam 4 . In one embodiment of the present invention, the concrete secondary beams 8 include 12-18, 2-3 concrete secondary beams 8 are arranged between every two adjacent concrete main beams 7, and the axis of the adjacent concrete secondary beams 8 The angle between them is 20-30 degrees.

The concrete transition section 9 is arranged on the upper part of the concrete slab 3, and the concrete transition section 9 is a linear thin-walled structure with a ring section, and the diameter of the bottom ring is larger than that of the top ring. The concrete transition section 9 is a structure of equal thickness, its wall thickness is 0.5-1.5m, and prestressed steel strands are distributed in the middle. The annular bottom surface of the concrete transition section 9 is located on the middle ring beam 5, and the circular section of the bottom surface is consistent with the middle ring beam; the height of the concrete transition section 9 is 20-40m. The concrete transition section 10 of the linear thin-walled structure helps to transmit the upper load to the concrete beam-slab system, and then distributes it to multiple steel cylinder foundations 1 . In addition, the concrete transition section 9 increases the self-weight of the whole structure, so that the whole structure can use the self-weight to resist part of the horizontal load.

A steel tower 10 is connected above the concrete transition section 9 , and the bottom end of the steel tower 10 is embedded in the upper part of the concrete transition section 9 .

The construction method of the above-mentioned multi-tube steel-concrete composite foundation structure is specifically carried out in accordance with the following steps:

(1) A plurality of steel cylinder foundations 1 are prefabricated on land, and after a plurality of steel cylinder foundations 1 are arranged on the horizontal plane to form a regular polygon according to the line connecting their center points, they are welded with the steel roof 2;

(2) The steel roof 2 is used as the bottom surface formwork of the concrete slab 3, and steel bars are bound on the steel roof 2, and the concrete slab 3, the outer ring beam 4, the middle ring beam 5, the inner ring beam 6, the concrete main beam 7, and the concrete secondary beam 8 and the concrete transition section 9 carry out pouring construction together;

(3) Hoist the overall structure completed by the above-mentioned pouring construction into the water, check the airtightness, install the steel tower 10 on the upper part of the concrete transition section 9, and install the machine head on the steel tower 10, adjust according to the towing requirements Draft of steel cylinder foundation;

(4) Floating and towing the multi-tube steel-concrete composite foundation structure and the nose;

(5) After the multi-tube steel-concrete composite foundation structure and the aircraft head are floated and towed to the designated sea area, they will first sink under their own weight, and then sink to the designated position under negative pressure;

(6) Reinforce the soil inside the steel cylinder foundation 1 after the subsidence is completed.

Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments. The above-mentioned specific embodiments are only illustrative and not restrictive. Those of ordinary skill in the art Under the enlightenment of the present invention, without departing from the purpose of the present invention and the scope of protection of the claims, personnel can also make specific changes in many forms, and these all belong to the protection scope of the present invention.

Claims (10)

1. a kind of more steel reinforced concrete combination foundation structures, including multiple identical steel cylinder bases, multiple steel cylinder bases are in level A regular polygon can be constituted according to its central point line on face to arrange, which is characterized in that multiple steel cylinder bases Top is connected with steel top plate jointly, and steel top plate top is provided with concrete slab；The steel roof center and the concrete Plate center offers circular through hole, and the circular through hole and the steel cylinder basis are on the steel top plate and the concrete slab Projection it is non-intersecting；The concrete slab top is provided with concrete changeover portion, and the concrete changeover portion is ring cross-section Linear type thin-wall construction, and bottom circle diameter is greater than top circle diameter；The top of the concrete changeover portion is provided with steel Tower processed, the steel tower drum bottom is inside the concrete changeover portion；

The concrete slab top surface is provided with outer-ring beam, middle ring beam, inner ring beam；The outer-ring beam is located at the concrete slab top surface Outer ledge at；The middle ring beam is located at the middle part of the concrete slab top surface, and is set under the concrete changeover portion Portion；The inner ring beam is set to the edge of the circular through hole of the concrete slab top surface；

The concrete slab top surface is radially uniform to be disposed with concrete girder, and the concrete girder is extended to by the inner ring beam The outer-ring beam；The concrete slab top surface is radially uniform between the every two adjacent concrete girders to be disposed with coagulation Native secondary beam, the concrete secondary beam extend to the outer-ring beam by the middle ring beam.

2. more steel reinforced concrete combination foundation structures of one kind according to claim 1, which is characterized in that the number on the steel cylinder basis Amount is 3-6；The radius on the steel cylinder basis is 10-15m, is highly 8-12m；The clear distance on the two neighboring steel cylinder basis It is 1-3 times of steel cylinder basis outer diameter.

3. more steel reinforced concrete combination foundation structures of one kind according to claim 1, which is characterized in that at the steel roof perimeter It is provided with upward steel floor, the steel floor is inserted in the concrete slab and the outer-ring beam.

4. more steel reinforced concrete combination foundation structures of one kind according to claim 1, which is characterized in that the concrete slab and institute The profile for stating steel top plate is consistent, the concrete slab with a thickness of 0.3-1m.

5. more steel reinforced concrete combination foundation structures of one kind according to claim 1, which is characterized in that the steel roof center and The radius of the circular through hole of the concrete slab is 0.5-1.0 times of basic 1 radius of steel cylinder.

6. more steel reinforced concrete combination foundation structures of one kind according to claim 1, which is characterized in that the concrete changeover portion For uniform thickness structure, wall thickness 0.5-1.5m, intermediate distribution has prestress wire.

7. more steel reinforced concrete combination foundation structures of one kind according to claim 1, which is characterized in that the outer rim of the outer-ring beam It is flushed with the concrete slab outer rim, and shape is consistent with the edge of the concrete slab；The width of the outer-ring beam is 0.5- 1.5m is highly 0.8-1.8m；The middle ring beam is located in the middle part of the concrete slab top surface, and shape is circular ring shape, and width is 0.5-1.5m is highly 0.8-1.8m；The radius of the middle ring beam is 1.5-2 times of the steel tower drum radius；The inner ring The internal diameter of beam is consistent with the diameter of the circular through hole, width 0.5-1.5m, is highly 0.8-1.8m.

8. more steel reinforced concrete combination foundation structures of one kind according to claim 1, which is characterized in that the concrete girder Width is 0.5-1.5m, is highly 0.8-1.8m；Angle between the adjacent concrete girder is 60 degree；The concrete Beam includes 12-18 root, and concrete secondary beam described in 2-3 root, adjacent institute are disposed between the every two adjacent concrete girders Stating the angle between concrete secondary beam axis is 20-30 degree.

9. more steel reinforced concrete combination foundation structures of one kind according to claim 1, which is characterized in that the steel tower drum is to become Section uniform thickness steel pipe, and base diameter is greater than top diameter.

10. a kind of construction method of more steel reinforced concretes combination foundation structure as claimed in claims 1-9, which is characterized in that according to Following steps carry out:

(1) the multiple steel cylinder bases of land fabrication, and multiple steel cylinder bases are connected according to its central point in the horizontal plane Line can be constituted after a regular polygon arranged, and be welded with the steel top plate；

(2) using the steel top plate as the bottom surface template of the concrete slab, the assembling reinforcement on the steel top plate, to described mixed Concrete board, the outer-ring beam, the middle ring beam, the inner ring beam, the concrete girder, the concrete secondary beam and described Concrete changeover portion carries out pouring construction together；

(3) overall structure that above-mentioned pouring construction is completed is hung in water, checks air-tightness, pacifies on the concrete changeover portion The steel tower drum is filled, and head is installed in the steel tower drum, the drinking water for adjusting the steel cylinder basis is required according to towage；

(4) the more steel reinforced concrete combination foundation structures and the head are subjected to transportation by driving towage；

(5) the more steel reinforced concrete combination foundation structures and the head transportation by driving towage are first self-possessed to after arriving specified sea area Sink, then carries out negative pressure and sink to designated position；

(6) soil body of the steel cylinder basic internal is reinforced after sinking.