KR101630522B1 - Suction foundation for pre-loading and construction method thereof - Google Patents

Abstract

The present invention relates to a suction foundation for pre-loading and a method of construction thereof. To this end, the upper body is composed of a hollow column with the upper part closed by the upper part, the lower part is open, and the column part is composed of a skirt part penetrating into the seabed ground; And an inner supporting portion provided inside the main body and configured to contact the bottom of the seabed when the main body is penetrated. After the lower surface of the inner supporting portion abuts against the bottom of the seabed, suction is possible in the space between the inner supporting portion and the upper plate , And a preloading is applied by suction. Accordingly, it is possible to load the suction pressure even after the intrusion of the suction foundation is completed.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suction foundation for pre-

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a suction foundation for preloading and a construction method thereof, and more particularly, to an apparatus and a construction method for applying preloading to a suction bucket foundation using a suction pressure.

The foundation of the marine uses mono files, suction bases, gravity bases and jacket bases. Suction Foundation is a file installed by using the pressure difference between the inside and outside of a file generated by discharging a fluid such as water or air inside the file to the outside. It is used in submarine floors and is used for marine fixed and floating structure supports or anchors, such as oil drilling platforms, offshore wind power bases. 1 is a conceptual view showing a penetration state of a conventional suction foundation as a longitudinal section. As shown in Fig. 1, the shape of the suction foundation 1 has a shape in which the upper end is closed by the upper plate and the lower end of the cup is opened so that suction pressure can be easily applied. The largest of the foundations (1) constructed to date is 32m in diameter and 37m in length, and is constructed on a 300m deep sea floor and used as the basis for oil drilling platforms. At this time, the suction foundation 1 may be provided with a discharge port and an injection port on the top plate or side surface of the upper part for discharging and injecting seawater, and a ring for use as a point of application in drawing can be provided at the center or side of the upper part.

1, the installation mechanism of the suction foundation 1 is as follows. When the suction foundation 1 is seated on the seabed layer 40, the lower end of the file is intruded to the seabed layer 40 to a certain depth by the weight of the file. In this state, seawater in the suction foundation (1) is drained to the outside by using a drainage device installed on the head of the suction foundation (1). Since the structure of the suction foundation 1 except for the lower end of the pile is completely blocked by the flow of seawater, the drained sea water can flow only through the seabed layer 40 at the lower end of the suction foundation 1. However, since the permeability of the seabed ground is very low, the drainage water is prevented from being introduced and recovered, so that the pressure inside the suction foundation 1 is lower than the pressure outside the suction foundation 1. As a result, a pressure difference between the inside and the outside of the suction foundation 1 is generated, thereby causing the suction foundation 1 to be intruded.

These suction bases are ① installed equipment at the maximum depth of 1600m without being restricted by water depth, ② installation is possible irrespective of the size of the suction foundation, and the larger the upper plate area, (3) It is possible to install at one time in a few hours, (4) It is possible to pull out with a positive pressure generated by injecting water into the suction foundation, so that it can be easily removed and reused if necessary. There is an advantage that the penetration resistance is reduced by the seepage of the submarine bed at the bottom of the suction foundation.

In addition, the structure using such a suction foundation can be applied regardless of the depth of water, (2) it can be installed in a short period of 1 to 2 days, and (4) the large-scale foundation can be installed in the seabed, The suction force causes suction pressure to be generated in the suction base due to the drawing, and the suction force acts as resistance force (or ground force) to increase the stability due to insertion. (In particular, there is a soft ground in the surface layer and a glass layer in the lower layer, which is sandy soil in the lower layer), and (5) it is possible to carry out the preceding loading and loading experiments using the suction pressure after installation.

Japanese Patent Laid-Open No. 11-158889 Japanese Patent Laid-Open No. 2005-256603

However, such a conventional suction foundation has a problem of settlement of the seabed which is generated after the sea structure is installed. The ground surface consists mainly of a clay layer and a sand layer. When a marine structure is installed, long-term settlement of the ground surface occurs due to the load of the marine structure. The settlement on the ground surface can be divided into three stages. First, as soon as the particle arrangement of the soil particles in the load structure of the offshore structure is instantaneously generated, the first groundwater generated by the excess pore water pressure A car consolidation settlement, and a settlement occurring after dissipation of excessive pore water pressure, and secondary settlement settlement caused by creep deformation over a long period of time.

In order to prevent such settlement, a pre-loading method for improving the ground surface can be used. The pre-loading method is a method of preloading equal or greater load of the offshore structure planned on the ground surface and inducing pre-settlement as necessary before installation of the offshore structure.

However, after the penetration of the suction foundation is completed and the top plate comes into contact with the seabed ground, it is difficult to drain the water. If the suction is continued, a large amount of the gravel leaks out, causing damage to the suction pump and weakening of the ground. Therefore, since the application of the suction pressure is difficult after the penetration of the suction foundation is completed, there is a problem that it is difficult to load the suction pressure more than the suction pressure required for the intrusion, and the suction foundation remarkably suitable for such a method has not been disclosed.

In order to solve this problem, the following prior art has been disclosed, but the above problem has not yet been solved completely.

Japanese Laid-Open Patent Publication No. 11-15889 discloses a method for preventing the rising of the internal ground in a suction foundation by providing a piston (press-in plate) penetrating the suction foundation up and down and pressing the internal ground using the self weight of the press- To prevent the rise of the internal ground during the installation of the suction. This is because if the internal ground of the suction foundation rises and the introduction port of the suction pump becomes blocked, the suction can no longer be performed. However, the Suction Foundation of Japanese Laid-Open Patent Application No. 11-15889 is intended to prevent the internal ground from rising due to the seepage of the internal ground so that the supporting force of the suction foundation is insufficient. In order to prevent the ground settlement, There is no purpose to do. In addition, since the piston of Japanese Laid-Open Patent Application No. 11-15889 is connected to the outer upper part of the suction foundation, there are many installation limitations such as connecting and fastening the structure to the upper part, It is difficult to use it for the purpose of applying.

Japanese Patent Application Laid-Open No. 2005-256603 discloses a structure for preventing settlement settlement of a seabed ground caused by the completion of a marine structure in a foundation of a ship, and has a plurality of catches at the end of a skirt of a suction foundation, Discloses a technique for draining the water of an existing aquifer in advance. However, since the end of the skirt is subjected to a considerable amount of resistance, it is expected that the ground will be crushed strongly so that the water collecting part will be damaged or the water will be difficult to suck, and there is a possibility that the soil will flow out and be sucked together. .

Accordingly, the present invention has been made to solve the above-described problems.

An object of the present invention is to provide an apparatus, a construction method, and an offshore wind power generation facility using the apparatus, which is capable of loading a suction pressure even after completion of intrusion of a suction foundation, have.

Hereinafter, specific means for achieving the object of the present invention will be described.

It is an object of the present invention to provide a suction foundation penetrated into a seabed sole for supporting a marine structure, the upper part being composed of a hollow columnar shape with the upper part closed by the upper plate, and the lower part being constituted by a skirt part penetrating into the seabed ground A main body; And an internal support portion provided inside the main body and configured such that a horizontal cross-sectional area is smaller than a horizontal cross-sectional area of the internal space of the main body, and the main support portion is configured to contact the submarine ground when the main body penetrates, Wherein a suction is possible in a space between the upper plate and the upper plate, and preloading is applied by the suction.

And an inner skirt formed on one side of the lower surface of the inner supporting part and configured to protrude downward.

The height adjusting unit may be connected to the upper plate at one end and connected to one side of the inner supporting unit. The height adjusting unit may adjust the height of the inner supporting unit in a vertical direction.

Another object of the present invention is to provide a method and apparatus for positioning a suction foundation according to an embodiment of the present invention at a specific installation position of a submarine ground; A penetration step of allowing the water in the suction foundation to be sucked out to the outside and performing the penetration of the suction foundation so that the internal support part constituting one part of the suction foundation is brought into contact with the ground surface of the seabed ground or positioned at a predetermined height; A preloading step of applying a preload to the suction foundation by applying an additional suction pressure to the inside of the suction foundation after the penetration of the suction foundation to a predetermined depth is completed; And a grouting step of injecting and solidifying the grout material into the inside of the suction foundation after the application of the pre-loading is completed.

As described above, the present invention has the following effects.

First, in accordance with an embodiment of the present invention, preloading is remarkably more prevalent than conventional ones on the foundation of a suction, so that a load acting by the installation of a marine structure or an additional external force due to waves, There is an effect of reducing settlement amount.

Second, according to the embodiment of the present invention, it is possible to load the suction pressure even after the penetration of the suction foundation is completed.

Third, according to an embodiment of the present invention, a considerable preloading can be realized with a simple structure, so that a significant economic effect and shortening of air are generated.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate preferred embodiments of the invention and, together with the description, And shall not be interpreted.
1 is a conceptual view showing a penetration state of a conventional suction foundation as a longitudinal section,
FIG. 2 is a perspective projection view showing a suction foundation according to an embodiment of the present invention, FIG.
FIG. 3A is a schematic view of a suction foundation in which an inner supporting portion is formed inside a skirt portion according to an embodiment of the present invention;
FIG. 3B is a schematic view of a suction foundation in which an inner support portion is formed at a lower end of a diaphragm according to an embodiment of the present invention;
4A, 4B, 4C, 4D and 4E are schematic views showing side cross-sections of a suction foundation according to an embodiment of the present invention,
5 is a schematic view showing a bottom surface of a suction foundation according to an embodiment of the present invention,
6A, 6B and 6C are schematic views showing side cross-sections of a suction foundation according to a first modification of the present invention,
7A and 7B are a schematic view showing a side cross-section of a suction foundation according to a second modification of the present invention,
FIG. 8 is a flowchart showing a construction method of a suction foundation according to an embodiment of the present invention;
9 is a diagram showing a relationship between a load and a settlement amount of a suction foundation according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following detailed description of the operation principle of the preferred embodiment of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may unnecessarily obscure the subject matter of the present invention.

The same reference numerals are used for portions having similar functions and functions throughout the drawings. Throughout the specification, when a part is connected to another part, it includes not only a case where it is directly connected but also a case where the other part is indirectly connected with another part in between. In addition, the inclusion of an element does not exclude other elements, but may include other elements, unless specifically stated otherwise.

Suction Foundation

With regard to the suction foundation, Figure 2 is a perspective projection view showing a suction foundation in accordance with one embodiment of the present invention. 2, the suction foundation 1 according to an embodiment of the present invention may include a main body, an inner support portion 12, and the like.

The body may be constructed in the form of a cylinder with the upper part closed by the upper plate 5 and the lower part open like the conventional suction foundation. The upper plate 5 may be formed in a plate shape, or may be formed in various shapes such as a dome shape. The columnar wall of the column may consist of a skirt portion 3, commonly referred to as a skirt. Also, in order to perform the purpose and function of a conventional suction foundation, the discharge port and the injection port may be provided on the top plate or the side surface for discharging and injecting seawater, and a ring for use as a point of action have. The body 10 may be provided with an internal support portion 12 and a connection portion 10 for connecting the body and the internal support portion 12 to fix the position of the internal support portion 12 according to an embodiment of the present invention . The inner support 12 can be configured at the inner stop of the suction foundation 1 and the connection 10 can be comprised of a single or multiple pillars or a single or multiple bracings to support the internal support 12 on a suction foundation 1).

In the suction foundation 1 according to the embodiment of the present invention, the internal support 12 can be configured to be disconnected from the suction foundation 1 without connection of the connection portion 10. FIG. 3A is a schematic view of a suction foundation in which an inner supporting portion is formed inside a skirt portion according to an embodiment of the present invention. FIG. 3B is a schematic view of an embodiment of the present invention wherein the inner supporting portion 12 is formed without connecting the connecting portion 10. FIG. 3 is a schematic view of a suction foundation in which an inner support portion is formed at a lower end of a diaphragm according to an example. As shown in Figs. 3A and 3B, the inner supporting portion 12 may be formed in the form of a disk which protrudes in the direction of the center of the cross section in the inner stop of the skirt portion 3 and has a through hole at one side thereof. The inner support 12 may also be configured to be connected to the end of the partition 20, which may be configured inside the suction foundation 1. As a result, the internal support 12 according to an embodiment of the present invention may be configured to be equal to or smaller than the cross-sectional diameter of the suction foundation 1, and may be formed to have a through- The area of the horizontal section of the inner support section 12 may be smaller than the area of the horizontal section of the inner space of the body. That is, the inner supporting portion 12 does not seal the inner space of the suction foundation 1. [

Since the space between the inner support portion 12 and the upper plate 5 is not filled with the gravel of the seabed ground even after the penetration of the suction foundation 1 is completed by the inner support portion 12 according to the embodiment of the present invention, There is an effect that it becomes possible to load additional suction pressure. In other words, with a very simple change of the internal structure of the suction base, considerable pre-loading is possible on the suction base. Therefore, according to one embodiment of the present invention, a stable suction foundation can be constructed at a low cost.

The shape of the inner support portion 12 can be determined according to the shape of the suction foundation 1. For example, it may have a shape similar to that of the inner bottom surface of the suction foundation 1, and may have an opening to partially pass the bottom of the bottom foundation 40 without closing the entire inner end surface of the suction foundation 1 . The opening of the inner supporting portion 12 may be located between the circumference of the inner supporting portion 12 and the skirt portion 3 or at least one inside the inner supporting portion 12 may be formed. An opening and a check valve may be formed in the opening formed in the inner supporting portion 12 so as to allow passage to the suctionable space which is a space between the upper plate 5 and the inner supporting portion 12 in the seabed ground 40 . When the grouting is performed on the upper portion of the inner support portion 12, the opening portion and the check valve are configured such that the grout material does not flow from the upper portion to the lower portion of the inner support portion 12, thereby allowing the grout material to flow into the lower portion of the inner support portion 12 It is possible to prevent a problem that a pulling force is generated.

The thickness of the inner supporting portion 12 may be the same as or thicker than the skirt portion 3 of the suction foundation 1. It should be made robust enough to withstand preloading by suction pressure.

The internal support 12 may be configured in various forms as will be discussed below to achieve the object of the present invention.

4a, b, c, d, e, and f are schematic diagrams illustrating side sections of a suction foundation in accordance with one embodiment of the present invention, in connection with various aspects of the inner support 12. Figs. 4A, 4B, 4C, 4D, 4E, and 4F show a state in which the penetration of the suction foundation is completed and the inner supporting portion 12 is in contact with the seabed ground 40 according to an embodiment of the present invention.

4A shows a basic example of a suction foundation according to an embodiment of the present invention. The entire inner skirt portion 3 is not penetrated by the inner support portion 12 even though the penetration of the suction foundation 1 is completed so that the inner support portion 12 and the skirt portion 3 It can be seen that space is generated. Hereinafter, a space generated between the inner supporting portion 12 and the skirt portion 3 after completion of the penetration of the suction foundation 1 is referred to as a suctionable space. Such a suctionable space prevents the upper plate 5 from directly contacting the seabed ground 40, thereby preventing the suction pump, which may be caused by the sediment leakage during the suction, from failing such as overloading and overloading, So that it can be loaded.

4B illustrates an example in which the suction-based inner support 12 is formed in a cone shape according to an embodiment of the present invention. 4B, when the shape of the inner support portion 12 of the suction foundation 1 is configured as a cone shape in which a vertex is inserted into the seabed ground 40, a certain portion of the inner support portion 12 is formed at a certain depth So that the contact area of the inner supporting part 12 is increased to increase the supporting force or to be advantageous in structural stability. In the case where the inner supporting part 12 is formed into a cone shape according to an embodiment of the present invention, the cone shape, inclination, position and number of the inner supporting part 12 are changed according to the state and environment of the seabed ground 40 So that an optional supporting force can be provided. It is effective in that even if the bottom surface of the seabed ground 40 is not constant, the eccentricity of the suction foundation 1 is not caused.

FIG. 4C shows an example in which a plurality of suction-based internal supports 12 are provided according to an embodiment of the present invention. As shown in FIG. 4C, when a plurality of inner supporting portions 12 are formed, the manufacturing cost of the suction foundation 1 is reduced and the transportation cost is reduced. In particular, 12) has an advantageous effect. In the case of a soft ground or a sandy ground, a supporting area supported by the inner supporting part 12 is smaller than an area of the inner supporting part 12, It is advantageous to constitute a plurality of the inner supporting portions 12 so that the supporting area can accommodate all the seabed ground 40 in the suction foundation 1. [

Fig. 4d shows an example in which the inner skirt 14 is formed with a short length downward at the circumferential end of the inner support portion 12 of the suction foundation 1 according to an embodiment of the present invention. The effect that the inner skirt 14 is formed downward at the circumferential end of the inner support portion 12 and penetrates into the seabed ground 40 as shown in Fig.4D, have. In addition, when grouting the suctionable space in the suction foundation 1 after the penetration of the suction foundation 1, the grout is prevented from flowing into the space between the inner support portion 12 and the bottom surface of the seabed ground 40 It is effective. When the grout flows into the space between the inner support portion 12 and the bottom surface of the seabed ground 40, a pulling force is exerted on the installed foundation 1. Further, by the inner skirt 14 constituted by the downward direction, the space under the inner supporting portion 12 is closed when the suction foundation 1 is penetrated, and the water is trapped, so that the resistance against the penetration of the suction foundation 1 can be increased have. In order to prevent such an increase in resistance, in the suction foundation 1 according to the embodiment of the present invention shown in FIG. 3D, at least one opening portion and a check valve are provided on one side of the inner supporting portion 12, It is preferable that the drainage from the lower part to the upper part of the drain pipe 12 is smooth.

An internal support 12 in the form of a cone as shown in Fig. 4b can also be combined with an inner skirt 14 as shown in Fig. 4d. It is also possible to combine the embodiments described within the scope of not obscuring the object of the present invention.

The inner skirt 14 may be configured to form a plurality of compartments at the bottom of the inner support 12, as well as at the circumferential ends of the inner support 12, as well as inside the lower surface. Even when the grouting material flows into the lower part of the inner supporting part 12, the total area of the lower part of the inner supporting part 12 It is possible to prevent the grout material from being diffused and the pulling support force of the inner support portion 12 is also raised so that the structural reinforcement effect of the inner support portion 12 is also expected.

4E shows an example in which the blocking wall 15 is formed on the circumferential end of the inner support portion 12 of the suction foundation 1 with a short upper length in accordance with an embodiment of the present invention. As shown in FIG. 4E, when the blocking wall 15 is formed at the upper end of the circumferential end of the inner supporting portion 12, grouting can be performed between the inner supporting portion 12 and the skirt portion 3 do. The blocking wall 15 according to the embodiment of the present invention allows the grouting only between the blocking wall 15 and the skirt portion 3 during the grouting operation after the penetration and installation of the suction foundation 1 is completed, It is possible to secure the stability of the liquid crystal display device. Therefore, according to the present invention, it is not necessary to grout the inner supporting portion 12, so that the amount of grouting and the time required for grouting can be shortened.

5 is a schematic diagram showing the bottom of a suction foundation according to one embodiment of the present invention, in connection with various aspects of the internal support 12. 5A shows an example in which a single circular inner supporting part 12 is provided according to an embodiment of the present invention, and FIG. 5B shows an example in which a plurality of circular inner supporting parts 12 12 shows an example in which a hexagonal single internal support 12 is provided according to an embodiment of the present invention, A plurality of hexagonal internal supports 12 are provided. As shown in FIG. 5, the inner supporting part 12 of the suction foundation 1 according to an embodiment of the present invention may be configured variously according to the ground condition, the type of the structure, the construction environment, and the like.

Variation example

With respect to the modification example of the suction foundation, various modifications can be applied as follows, so long as the object of the present invention is not adversely affected by the suction foundation according to the embodiment of the present invention.

6A, 6B, and 6C are schematic diagrams showing side cross-sections of a suction foundation according to a first modified example of the present invention. 6A, 6B, and 6C, a pneumatic pressure jack or the like may be formed in the connection portion 10 to configure a height adjusting portion 11 for adjusting the height of the internal supporting portion 12. [ The height adjusting portion 11 may be configured by a hydraulic jack or a pneumatic jack. One end of the height adjusting portion 11 may be connected to the upper plate 5 and the other end may be connected to the inner supporting portion 12 and at least one may be formed in the vertical direction.

6A, when the ground surface and the actual ground surface are expected to be different from each other when the construction is performed, the height adjustment unit 11 according to the first modification can adjust the height adjustment unit 11 The inner supporting portion 12 can be brought into contact with the actual ground surface of the seabed sole 40. As a result, Further, when the suction foundation 1 is excessively intruded, there is an effect that the penetration depth of the suction foundation 1 can be adjusted upside down. When the suction foundation is constructed as in the first modification of the present invention, the effect of preventing the eccentricity of the suction foundation 1 is generated despite the various inclination of the bottom floor 40 and the form of the ground layer. It is possible to adjust the intrusion angle of the suction foundation, to cope with the change of the ground surface, or to adjust the verticality of the suction foundation.

6B, when the ground surface of the seabed ground 40 is inclined at a specific angle, the inner supporting portion 12 is formed at the same angle as the ground surface So that it is possible to configure the seabed sole 40 and the inner supporting portion 12 to be in contact with each other with a maximum area. 6C, even when a plurality of inner supporting portions 12 are provided and a plurality of height adjusting portions 11 are formed on each inner supporting portion 12, as shown in FIG. 6B, The effect of the suction foundation 1 according to the modified example can be realized. As shown in FIG. 6C, when the plurality of inner supporting portions 12 are provided, the load applied to one height adjusting portion 11 is considerably reduced, thereby preventing the height adjusting portion 11 from being overloaded . 6C, when the plurality of inner supporting portions 12 are provided, it is possible to precisely control the vertical degree of the suction base 1 by changing the height of each of the inner supporting portions 12 .

7A and 7B are schematic views showing a side cross-section of a suction foundation according to a second modification of the present invention. 7A and 7B, in the suction foundation 1 according to the second modification of the present invention, the grout bag 13 is formed on the lower surface of the inner support portion 12, which is brought into contact with the seabed ground 40 . The grout bag 13 is installed at a lower portion of the inner support portion 12 and the inner support portion 12 serves to fix the grout bag 13 and to form a water supply space at the upper portion of the grout bag 13, It can be configured to play a role of reminding.

The grout bag 13 may be made of geosynthetic fibers made of synthetic resin or the like and may be partially or wholly cut off of the inner injection material and changed in shape depending on the shape of the ground surface. The bottom of the seabed 40 and the inner supporting part 12 are adjusted by adjusting the height of the inner supporting part 12 directly by using the height adjusting part 11 or the like and separately adjusting the water or grout solution injected into the grouting bag 13. [ The height of the suction foundation 1, the degree of vertical adjustment, and the like can be performed. The injection material injected into the grout bag 13 may be divided into a non-fixed fluid and a fixed fluid. When the non-fixed fluid is injected into the grout bag 13, the grout bag 13 can be temporarily fixed, repetitive injection and discharge can be freely performed, and the pressure can be easily adjusted. An effect is generated. The fixed fluid includes a grout liquid such as cement. When the fixed fluid is injected into the grout bag 13, the grout bag 13 can be fixed for a long period of time.

According to the grout bag 13 according to the second modification, there is an effect that the intrusion angle of the suction foundation can be adjusted, the change in the ground surface can be adjusted, or the verticality of the suction foundation can be adjusted.

According to the grout bag 13 according to the second modified example, when the expected ground surface and the actual ground surface are different as shown in FIG. 7A, the grout bag 13 It is possible to make the inner supporting portion 12 to be supported on the actual ground surface of the seabed ground 40 by using the grout filling. 7B, when the ground surface of the seabed ground 40 is inclined by a specific angle, the inner supporting portion 12 is located at the bottom of the seabed using the grout filling of the grout bag 13 without changing the inner supporting portion 12 to the same inclination. So that it becomes possible to support the ground surface of the ground 40 on the actual ground surface.

According to the first and second modified examples, it is possible to easily cope with the height and inclination change of the ground surface of the seabed ground 40, and the first and second modified examples can be respectively used or used together.

Construction method

8 is a flowchart illustrating a method of constructing a suction foundation according to an embodiment of the present invention. As shown in FIG. 8, the basic method of sucking construction according to an embodiment of the present invention may include a positioning step, a penetration step, a pre-loading step, and a grouting step.

The position setting step is a step in which the suction foundation according to one embodiment and the modification of the present invention is seated at the installation position of the seabed ground 40 and the skirt portion 3 of the suction foundation 1 ) Is intruded into the seabed layer (40).

In the penetration step, the suction pump is operated to suck the water in the suction foundation 1 to drain it to the outside. By the pipe input formed by the inner and outer hydraulic pressure differences of the suction foundation 1, the penetration of the suction foundation 1 . In this penetration step, the inner supporting portion 12 is brought into contact with the ground surface of the seabed ground 40 or penetrated to a predetermined position even before it comes into contact with the ground surface.

In the pre-loading step, after the penetration of the suction foundation 1 is completed, the suction pressure is continuously applied by using the suction pump so that the load due to the suction pressure in addition to the self weight of the suction base 1 is applied to the suction foundation 1 .

The grouting step is a step of injecting and solidifying the grout material into the space between the top plate 5 of the suction foundation 1 and the bottom surface of the seabed ground 40 after the application of the necessary preloading is completed, To prevent the inflow of additional soil to the inner space of the suction foundation 1 and to enhance the supporting force of the suction foundation 1 and the strength of the foundation structure.

A significant effect produced by the internal support 12

Application of preloading

According to the above-described suction foundation (1), preloading can be easily applied to the suction foundation (1). The load applied at the time of completion of installation of the suction foundation 1 is basically the same as the weight W of the suction foundation 1 but the internal support portion 12 is located at the bottom of the seabed 40, An additional suction load is applied to the suction foundation 1, and this additional suction load exerts a pre-loading effect on the suction foundation 1. In this case, The suction load can be derived by Equation (1) below.

In Equation (1), P represents the suction load, Δp represents the pressure difference between the inside and the outside of the suction foundation 1, and A represents the area of the upper plate 5.

Therefore, since the seabed ground 40 is in a state of being loaded as much as the suction load before the installation of the offshore structure and is improved so as to increase the strength of the ground, The settlement amount of the foundation 1 can be reduced and the safety of the suction foundation 1 can be improved. FIG. 9 is a graph showing a relationship between a load and a settlement amount of a suction foundation according to an embodiment of the present invention, in relation to an effect of reducing the settlement amount due to preloading. In FIG. 9, S1 is the settlement amount due to preloading, S2 is the settlement amount caused by the offshore structure and external load when no preloading is applied, and S3 is settlement amount due to offshore structure and external load when preloading is applied. As shown in FIG. 9, when the pre-loading is applied, the seabed ground 40 is improved and it can be confirmed that the settlement amount due to the marine structure and the external load is abruptly reduced.

In the case of the conventional conventional suction foundation 1, the suction load is applied in addition to the own weight of the suction foundation 1 in the installation process of the suction foundation 1, but the upper plate 5 of the suction foundation 1, The suction pressure action after the contact with the ground surface of the ground 40 (after intrusion was completed) was almost impossible. Therefore, in the case of the conventional suction foundation (1), it is inevitable to use another complicated method for pre-loading.

As a result, in order to pre-load, a load equal to or greater than the load of a marine structure to be installed is required. However, when the suction foundation 1 according to an embodiment of the present invention is used, It is possible to apply preloading.

Reduced grouting force

According to the suction foundation 1 according to the embodiment of the present invention, not only the preloading effect is generated by the internal support portion 12 but also the pulling force which can be generated in the internal grouting work of the suction foundation 1 is reduced .

Regarding the pulling force that can be generated in the inner grouting work of the suction foundation 1, when there is no inner supporting portion 12, a pulling force as shown in Equation (2) is generated.

In the above equation (2), U1 is the pullout force due to the inner grout in the absence of the inner support portion 12, Pgrout is the grout pressure, and A is the horizontal cross-sectional area of the suction foundation 1. [

In Equation (3), U2 is the pullout force due to the internal grout when the inner support portion 12 is present, Pgrout is the grout pressure, A is the horizontal cross-sectional area of the suction foundation 1, and Ainnerfooting is the area of the inner support portion 12.

As shown in Equations (2) and (3), when the inner supporting portion 12 is present, the area where the grout contacts the seabed ground 40 and the grout pressure is applied is considerably reduced. As a result, the pulling force by the internal grouting of the suction foundation 1 is reduced by the internal support portion 12.

Correspond to changes in the ground surface or adjust the verticality of the suction foundation

According to the first aspect of the present invention, since the preloading effect is generated by the internal support part 12, it is possible to cope with the change of the ground surface when the suction foundation 1 is installed, There is an effect that the verticality of the foundation can be adjusted.

Offshore wind power generation facility

The offshore wind power generation facility according to an embodiment of the present invention may be constituted of a suction foundation assembly, a tower, and a power generation unit.

The suction base assembly may be constructed by combining a plurality of suction bases according to an embodiment of the present invention, and the suction bases according to the first and second modified embodiments may also be used. According to the first and second modified examples of the present invention, there is an advantage that the arrangement of the seabed ground is not greatly required. In other words, the disadvantage that occurs when using the conventional gravity bases is that the bottom of the seabed soils are flattened to align horizontally, and the construction cost and the increase of air are eliminated.

The tower may be configured to be coupled to the mounting base of the suction foundation assembly and to be oriented vertically upwards. And a power generating unit for wind power generation may be provided at the end.

The power generation unit may be configured in the same manner as a conventional offshore wind power generation facility, and may be configured of a rotating unit including a rotor and a blade, and a nacelle housing a generator that generates electricity by rotation of the rotating unit.

If the offshore wind power generation facility is installed using the suction foundation according to the present invention, the application of the preloading is easy, the horizontal adjustment is easy, and the pulling force by the grouting operation is reduced.

The size, position, and arrangement of the suction foundation 1, the internal support 12, and the connecting portion 10 are not limited to those shown in the drawings. In order to achieve the object of the present invention, It is desirable to be determined depending on the type of marine structure.

As described above, those skilled in the art will appreciate that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. It is therefore to be understood that the above-described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

1: Suction Foundation
3: skirt part
5: Top plate
10: Connection
11: Hydraulic Jack
12: inner support
13: Grout bag
14: inner skirt
16: Check valve
17: Grouting
20:
40: Submarine ground

Claims (4)

In a suction foundation penetrated into the seabed to support the marine structure,
A main body having an upper portion closed by an upper plate, a lower portion formed by an opened hollow columnar shape, and a columnar surface including a skirt portion penetrating into a seabed ground; And
An inner supporting portion provided inside the main body and having a horizontal cross-sectional area smaller than a horizontal cross-sectional area of the inner space of the main body, and contacting the bottom of the main body when the main body is penetrated;
Lt; / RTI >
A suction is possible in a space between the inner support and the upper plate, preloading is applied by the suction,
An inner skirt formed on one side of the lower surface of the inner supporting part and configured to project downward; And
A height adjusting unit connected to the upper plate at one end and connected to one side of the inner supporting unit, the height adjusting unit being adjustable in length in the vertical direction to adjust the height of the inner supporting unit;
Further comprising: a suction port for receiving suction from the suction port.
delete delete A positioning step of placing the suction foundation according to claim 1 at a specific installation position of the seabed ground;
A penetration step of allowing the water in the suction foundation to be sucked out to the outside and performing the penetration of the suction foundation so that the internal support part constituting one part of the suction foundation is brought into contact with the ground surface of the seabed ground or positioned at a predetermined height;
A preloading step of applying a preload to the suction foundation by applying an additional suction pressure to the inside of the suction foundation after the penetration of the suction foundation to a predetermined depth is completed; And
A grouting step of injecting and solidifying the grout material into the suction foundation after the application of the pre-loading is completed;
And a second step of applying a suction force to the base.

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