LU102092B1 - Newly-built or expanded wind power foundation structure on soft ground and construction method thereof - Google Patents

Abstract

The invention relates to a newly-built or expanded wind power foundation on soft ground and construction method thereof, which being built under following sequence from bottom to top: arranging a circular pile-group in the soft ground or around the existing foundation, providing a ring beam on the top of the circular pile-group, providing a roof plate inside the ring beam or surrounding the existing base by the ring beam, providing a pillar on the roof plate or the base, and providing reinforcement members between the ring beam and the pillar for supporting the pillar and transmit the load thereof, and then providing the foundation ring on the pillar for fixing the tower so as to complete the construction of the new or expanded wind power foundation, thus meeting the actual needs of construction of newly-built or expanded wind power foundation on soft ground.

Description

NEWLY-BUILT OR EXPANDED WIND POWER FOUNDATION STRUCTURE ON SOFT GROUND AND CONSTRUCTION METHOD THEREOF

TECHNICAL FIELD The present invention relates to the technical field of wind power foundation structure and in particular to a newly-built or expanded wind power foundation structure on soft ground and construction method thereof.

BACKGROUND OF THE PRESENT INVENTION Wind energy is an inexhaustible renewable clean energy. As one of the most promising sustainable projects in the world, foundation structure used to install wind turbine towers is the key to ensuring the sustainable development of wind power generation.

However, due to the limited national land resources, the construction of wind farms on land or offshore also faces problems such as shortage of land resources and complex geological conditions. In order to make full use of land resources and wind resources, wind farms often need to be built on in areas with weak geological conditions such as soft ground.

When building a wind power foundation in a soft ground, complicated foundation treatment procedures such as rock-socketed piling are often required in prior art, which are not economical in terms of efficiency and cost.

In addition, the service life of wind farms lasts generally 20 years. Some wind farm units and their infrastructures that have been put into operation at the beginning of this century or earlier have reached the end of their service life and need to be updated or expanded. However, since the wind farms constructed in the early days often occupy the advantageous wind resources, it is a great waste of resources to completely abandon the existing wind farms.

In particular, these wind power foundations, which are set in the soft ground,

have suffered long-term fatigue damage, which may cause their foundations to collapse.

Traditional gravity-based foundation structure relies on the theory and design of reinforced concrete, which is not suitable for soft ground, because such soft ground will cause foundation settlement and other problems with the use time, the weight of the wind turbine and load changes.

CN 202000369U discloses an affiliated mudmat structure of a steel framework offshore wind turbine foundation, which is provided with a plurality of steel sleeves; a plurality of connection clamping grooves are welded on the outer wall of the bottom of the steel sleeve; and at least two mudmats are fixed through bolts by the connection clamping grooves. However, this structure is only suitable for offshore foundation and cannot solve the settlement problem of soft ground.

CN102926949A discloses a method for transporting an offshore turbine in a floating manner, in which a frame construction is mounted on a deck of a transportation and installation ship; a wind turbine foundation connected to a transition segment is prepared in advance; the transition segment is extended from the frame construction; the wind turbine foundation is temporarily secured with the frame construction; the wind turbine tower, wind turbine head and blades are hoisted in turn and then are assembled to form an entire wind turbine machine; and finally the entire wind ‘turbine machine is conveyed to the installation place. The method may achieve transporting the entire wind turbine machine in a single step. However, due to the large size of the cylindrical foundation, it is not economically advantageous compared with mono-pile type or jacket-pile type foundations.

JP2006083603A provides a method of constructing a mono-pile type foundation which is a support means of a wind power facility or the like, on the ground such as a coast area or on the sea-bottom ground, when a weak stratum is deposited on a support layer of the ground, a setting depth part of a mono- pile is left as the unimproved ground. However, this method needs to improve the soft ground before setting up a single pile, which increases the difficulty of construction. Therefore, when the existing equipment is restricted, it is necessary to build an expanded foundation on the basis of the existing wind turbines. It is urgent to develop an expanded wind power foundation structure on soft ground and construction method thereof.

SUMMARY OF THE PRESENT INVENTION To overcome the deficiencies of the prior art, the present invention provides a newly-built or expanded wind power foundation structure on soft ground and construction method thereof, which is used for fixing the tower of wind turbine. The present invention makes full use of land resources, avoids rock- socketing, does not require large-area foundation treatment, can use existing small equipment to complete the on-site construction of newly-built or expanded wind power foundations. The present invention can complete the construction operation safely, economically, efficiently and conveniently, and can improve economic and social benefits. For this purpose, the following technical solutions are employed in the | present invention. | A newly-built wind power foundation on soft ground, the foundation includes the following from bottom to top: | | A circular pile-group, a ring beam, a roof plate, a pillar, a plurality of reinforcement members and a foundation ring. | The circular pile-group includes more than four piles, one end of each pile extends into the soft ground, while the other end is connected with the ring beam, and the side walls of the pile are contacted with the side walls of the adjacent piles. The ring beam is arranged on the top of the piles of the circular pile-group, and is in contact with the top of the piles, respectively. The roof plate is arranged along the circumferential direction of the inner side of the ring beam, and the outer peripheral side wall of the roof plate is at least partially connected with the inner peripheral side wall of the ring beam.

The pillar is axially arranged on the upper part of the roof plate, and a foundation ring is arranged on the top of the pillar for the installation of the tower of the wind turbine.

A plurality of reinforcement members are circumferentially arranged on the side wall of the pillar, one end of each reinforcement member is connected with the side wall of the pillar, and the other end is connected with the ring beam; wherein the reinforcement members are used to support the pillar and transmit the load thereof.

An expanded wind power foundation on soft ground, wherein the expanded foundation refers to an expanded foundation built on the existing wind power foundation on soft ground; and the existing wind power foundation includes a base and a platform arranged on the base, and the base being circular or polygonal; the expanded foundation includes the following from bottom to top: A circular pile-group, a ring beam, a pillar, a plurality of reinforcement members and a foundation ring.

The circular pile-group is arranged along the outer periphery of the base, which includes more than four piles, one end of each pile extends into the soft ground, while the other end is connected with the ring beam, and the side walls of the pile are contacted with the side walls of the adjacent piles.

The ring beam is arranged on the top of the piles of the circular pile-group, and is in contact with the top of the piles.

The base is arranged in the inner side of the ring beam, and the outer peripheral side wall of the base is at least partially connected with the inner peripheral side wall of the ring beam.

The pillar is sleeved on the side wall of the platform, the top of the pillar is fixed with a foundation ring for the installation of the tower of the wind turbine; the distance from the top of the pillar to the top of the platform is in the range of

1m-3m.

A plurality of reinforcement members are circumferentially arranged on the side wall of the pillar, one end of each reinforcement member is connected with the side wall of the pillar, and the other end is connected with the ring beam; wherein the reinforcement members are used to support the pillar and transmit the load thereof.

Further, each reinforcement member is a triangular support arranged on the roof plate or the base, one side of which is connected to the side wall of the pillar, and the other side is connected to the ring beam.

Further, the reinforcement members include a plurality of pairs of radial supports and cant beams, wherein one end of the radial support is connected to the bottom of the side wall of the pillar, and the other end is connected to the inner wall of the ring beam; one end of the cant beam is connected to the upper part of the side wall of the pillar, and the other end is connected to the connection part of the ring beam and the radial support.

Further, the pillar is a hollow cylinder with a ring structure at its top, and a cavity is formed beneath the ring structure, and the foundation ring and the tower installed on the foundation ring are in detachable connection with the ring structure. | Further, the foundation ring and the tower installed on which are in screw connection with the ring structure, the bottom of the ring structure is provided | with an anchor plate which provides with holes thereon, a plurality of bolts penetrate the holes and enter the holes of the ring structure.

Further, the base/ roof plate is circular or polygonal, which is connected to the ring beam through its circular edges or polygonal corners.

Further, the piles of the circular pile-group are selected from a group consisting of Larsen steel sheet piles, steel precast piles or concrete piles, wherein the concrete piles are bored concrete piles or precast concrete piles.

Further, the ring beam is a reinforced concrete beam.

Further, when the piles of the circular pile-group are Larsen steel sheet piles or steel precast piles, multi-layer shear nails are provided on the top of the piles; and when the piles of the circular pile-group are concrete piles, the top of the concrete piles have protruded embedded steel bars.

A construction method for a newly-built or expanded wind power foundation structure on soft ground, comprising: according to the load parameters of the wind turbine and the ground bearing capacity of the soft ground where the wind power foundation to be built or expanded, determining the type of the piles of the circular pile-group, calculating the penetration depth of the piles, and determining the surrounding area of the circular pile-group and the construction parameters for constructing the wind power foundation; constructing the circular pile-group, the ring beam, the pillar, the reinforcement members and the foundation ring sequentially from bottom to top in the soft ground; wherein, the piles of the circular pile-group are constructed in the following manner: piling a plurality of piles into the soft ground by using a pile driving equipment or in-situ drilling and then pouring concrete to form concrete piles in the soft ground; wherein the side walls of each pile are contacted with the side walls of the adjacent piles.

Optionally, the ring beam, the roof plate, the pillar and the reinforcement members are constructed by the following steps: providing multi-layer shear nails on the top of the piles or providing protruded embedded steel bars extended upwards of 20cm-50cm from the top of the piles; during the construction of the expanded wind power foundation, it | is further required to performing roughing treatment and embedding bars to the round edges or polygonal corner surfaces of the base to be connected to the ring beam; binding the steel bars of the ring beam, the roof plate, the pillar and the reinforcement members, and reserving steel joints for each component to connect with other component;

building formworks of the ring beam, the roof plate, the pillar and the reinforcement members; pouring concrete in the formworks, and connecting the ring beam, the roof plate, the pillars and the reinforcement members as a whole by shear nails.

Optionally, the ring beam, the roof plate, the pillar and the reinforcement members are prefabricated or partially prefabricated on land, all the prefabricated ring beam, the roof plate, the pillar and the reinforcement members are reserved with steel joints for connecting with each other; and then the prefabricated components are transported to the installation site, and the prefabricated components are connected with each other by the reserved steel joints, and then the joints are casted with concrete so as to complete the construction of ring beam, the roof plate, the pillar and the reinforcement members.

Compared to the prior art, the beneficial effects of the present invention are as follows:

1. the present invention is to build a newly-built or expanded wind power foundation structure on soft ground, which being build under following sequence from bottom to top: arranging the circular pile-group in the soft ground or around the existing wind power foundation, providing the ring beam on the top of the circular pile-group, providing the roof plate inside the ring beam or i surrounding the existing base by the ring beam, providing the pillar on the roof plate or the base, and providing reinforcement members between the ring beam and the pillar for supporting the pillar and transmit the load thereof, and then providing the foundation ring on the pillar for fixing the tower so as to complete the construction of the new or expanded wind power foundation, thus meeting the actual needs of construction of newly-built or expanded wind power foundation on soft ground;

2. the present invention combines the advantages of traditional expanded foundation and cylindrical foundation, and is a novel pile-group cylindrical foundation structure formed by adding steel sheet piles or concrete piles on the periphery of traditional foundation; by using this construction method, the expanded foundation and the existing foundation are connected as a whole through the ring beam, the present invention makes full use of the top cover pressure of the expanded foundation and the active and passive earth pressure of the side wall of the existing cylindrical foundation to resist the large bending moment load generated during the operation of the wind turbine, which improves the bearing capacity of the foundation structure; the wind farms adopted the newly-built and or expanded foundation according to the present invention can fully utilize the land resources, reduce the land occupation area, reduce the resource occupation cost, avoid rock-socketed piling or complicated foundation treatment before construction, thus improving the constructing efficiency and effectively using the existing wind power foundation, having the | advantages of safe, economic, efficient and convenient, can effectively improve | the economic benefits of the enterprise and obtain better social benefits;

3. the present invention has unique design ideas, simple and diversified construction methods; and the obtained foundation according to the present invention has high strength and large bearing capacity which guarantees the safe operation of the wind turbine, and saves infrastructure investment, and can obtain better economic and social benefits. Therefore, it has great promotion and application value.

BRIEF DESCRIPTION OF THE DRAWINGS The following drawings are only drawings of some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative labor. However, these other drawings also belong to the drawings required for the embodiments of the present invention.

FIG. 1 is a schematic diagram of the existing wind power foundation; FIG. 2 is a schematic diagram of a newly-built foundation according to an embodiment of the present invention; FIG.3 is a sectional view of the newly-built foundation shown in FIG. 2;

FIG.4 is a schematic diagram of an expanded foundation according to an embodiment of the present invention; FIG.5 is a sectional view of the expanded foundation shown in FIG. 4; FIG. 6 is a block diagram of the construction method for an expanded wind power foundation according to an embodiment of the present invention: FIG.7 shows a schematic diagram of the circular pile-group by using Larsen steel sheet piles and having shear nails on the top of the piles according to the embodiments 1, 2 of the present invention; and FIG.8 shows a schematic diagram of the circular pile-group by using concrete piles according to the embodiments 1, 2 of the present invention.

In which: 110: base 120: platform 210: circular pile-group 211: Larsen steel sheet pile | 212: shear nail 213: concrete pile 220: ring beam 230: roof plate 240: pillar 241: ring structure 242: anchor plate 250: reinforcement member 251: radial support 252: cant beam 260: foundation ring.

DETAILED DESCRIPTION OF THE PRESENT INVENTION In order to make the purpose, technical solutions, beneficial effects, and significant progress of the present invention clearer, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings provided in the embodiments of the present invention. Obviously, all the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work shall fall within the protection scope of the present invention.

It should be noted that the terms "first" and "second" in the description and claims of the present invention and the drawings of the embodiments of the present invention are only used to distinguish different objects, rather than to describe a specific sequence; in addition, the term "including" and any variations thereof are intended to cover non-exclusive inclusion: for example, a process, method, system, product, or device that includes a series of steps or units is not limited to the listed steps or units, instead, it optionally further includes steps or units that are not listed, or optionally further includes other steps or units inherent to the process, method, product, or equipment.

Unless otherwise clearly defined and defined, the terms "installation", "connection", "fixation" and other terms should be understood in a broad sense | in the present invention. For example, it may be a fixed connection, a detachable connection or a movable connection. It can also be integrated, which can be the internal communication of two elements or the interaction between two elements. Unless otherwise clearly defined, those skilled in the art can understand the specific meanings of the above terms in the present invention according to specific circumstances.

It should also be noted that the following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

The technical solution of the present invention will be described in detail with specific embodiments as follows.

The newly-built wind power foundation in the following embodiments refers to a newly-built wind power foundation on soft ground, and the expanded wind power foundation in the following embodiments refers to an expanded wind power foundation expanded on the existing wind power foundation on soft ground.

Embodiment 1 Embodiment 1 provides a newly-built wind power foundation on soft ground for the installation of the tower of the wind turbine.

" LU102092 As shown in FIGs. 2, 3, a newly-built wind power foundation on soft ground, including a circular pile-group 210, a ring beam 220, a roof plate 230, a pillar 240, a plurality of reinforcement members 250 and a foundation ring 260.

One end of the circular pile-group 210 vertically or obliquely extends into the soft ground, the other end is connected with the ring beam 220, and the side walls of each pile are contacted with the side walls of the adjacent piles. The piles of the circular pile-group 210 are selected from a group consisting of Larsen steel sheet piles, steel precast piles or concrete piles, wherein the concrete piles are bored concrete piles or precast concrete piles. FIG.7 shows a schematic diagram of the circular pile-group by using Larsen steel sheet piles and having shear nails on the top of the piles, the top of the Larsen steel sheet piles 211 or the steel precast piles are provided with multi-layer shear nails 212. And the piles of the circular pile-group 210 can also be concrete piles 231 as shown in FIG.8, and the concrete piles 231 can be bored concrete piles or precast concrete piles.

The ring beam 220 is arranged on the top of the piles of the circular pile- group 210, and is in contact with the top of the piles. Optionally, the ring beam 220 is a reinforced concrete beam, and the steel bars wherein is selected from a group consisting of Larsen steel sheet piles or steel precast piles; the top of the steel bars are provided with multi-layer shear nails 212, or the top of the concrete piles have protruded embedded steel bars; the shear nails or the protruded embedded steel bars are poured into the concrete of the ring beam.

The pillar 240, which is axially arranged on the roof plate 230, is arranged in the center of the roof plate 230, and a foundation ring 260 is arranged on the top of the pillar for the installation of the tower of the wind turbine. As shown in FIG.3, the pillar 240 is a hollow cylinder with a ring structure 241 at its top, and a cavity is formed beneath the ring structure 241, a plurality of holes are provided on the ring structure 241; and the foundation ring 260 and the tower installed on which are installed on the pillar by bolts inserted into the holes and fastened by nuts. The cavity is formed beneath the ring structure 241 for

: installing or replacing the bolts (the protruding elements of the top of the foundation ring 260 as shown in FIG. 3 are the bolts). The bottom of the ring structure 241 is also provided with an anchor plate 242 with a plurality of holes for passing the bolts through the holes into the holes of the ring structure 241.

A plurality of reinforcement members 250 are circumferentially arranged on the side wall of the pillar 240, one end of each reinforcement member 250 is connected with the side wall of the pillar 240 and the other end is connected with the ring beam 220; wherein the reinforcement members are used to support the pillar and transmit the load thereof. As shown in FIG.2, each reinforcement member 250 includes a radial support 251 and a cant beam 252 arranged in pairs, wherein one end of the radial support 251 is connected to the bottom of the side wall of the pillar 240, and the other end is connected to the inner wall of the ring beam 220; one end of the cant beam 252 is connected to the upper part of the side wall of the pillar 240, and the other end is connected to the connection part of the ring beam 220 and the radial support 251.

Optionally, as shown in FIGs. 4, 5, each reinforcement member 250 is a triangular support arranged on the roof plate 230, one side of which is connected to the side wall of the pillar 240, and the other side is connected to the ring beam 220.

Embodiment 2 Embodiment 2 provides an expanded wind power foundation on soft ground for the installation of the tower of the wind turbine.

As shown in FIGs. 4, 5, an expanded wind power foundation on soft ground, including a circular pile-group 210, a ring beam 220, an existing foundation, a pillar 240, a plurality of reinforcement members 250 and a foundation ring 260. As shown in FIG. 1, the existing wind power foundation includes a base 110 and a platform 120 arranged on the base 110. The shape of the base 110 is not limited, may be a circle as shown in FIG. 1 or a polygon (not shown in the drawings).

The structure of the expanded wind power foundation is similar to the embodiment 1, and will not be repeated here, and only the differences will be described below.

An expanded wind power foundation on soft ground, including a circular pile-group 210, a ring beam 220, a base 110, a platform 120, a pillar 240, a plurality of reinforcement members 250 and a foundation ring 260. The base 110 is of circular or polygonal shape.

The circular pile-group 210 is arranged along the outer periphery of the base 110, which includes more than four piles, one end of each pile extends into the soft ground, while the other end is connected with the ring beam 220, and the side walls of the pile are contacted with the side walls of the adjacent piles.

The ring beam 220 is arranged on the top of the piles of the circular pile- group 210, and is in contact with the top of the piles.

The base 110 is arranged in the inner side of the ring beam 220, and the outer peripheral side wall of the base 110 is connected with the inner peripheral side wall of the ring beam 220.

The pillar 240 is sleeved on the side wall of the platform 120, the top of the pillar 240 is fixed with a foundation ring 260 for the installation of the tower of the wind turbine; the distance from the top of the pillar to the top of the platform is in the range of 2m.

A plurality of reinforcement members 250 are circumferentially arranged on the side wall of the pillar 240, one end of each reinforcement member 250 is connected with the side wall of the pillar 240, and the other end is connected with the ring beam 220; wherein the reinforcement members are used to support the pillar 240 and transmit the load thereof.

The structure and the function of the pillar 240 of the expanded wind power foundation is similar to that of the newly-built wind power foundation in the embodiment 1, so it will not be repeated here.

The structure and the function of the reinforcement members 250 of the expanded wind power foundation are similar to those of the newly-built wind power foundation in the embodiment 1, so it will not be repeated here.

The structure and types of the circular pile-group 210 and the ring beam 220 are also the same as those in the embodiment 1, so they will not be repeated here.

Embodiment 3 As shown in FIG. 6, a construction method for a newly-built or expanded wind power foundation structure on soft ground, comprising: S1: according to the load parameters of the wind turbine and the ground bearing capacity of the soft ground where the wind power foundation to be built or expanded, determining the type of the piles of the circular pile-group, calculating the penetration depth of the piles, and determining the surrounding area of the circular pile-group 210 and the construction parameters for constructing the wind power foundation.

S2: constructing the circular pile-group 210 in the soft ground according to the determined surrounding area or constructing the circular pile-group 210 in the soft ground surrounding the existing foundation; Wherein, the step of “constructing the circular pile-group 210” comprising: | driving a plurality of piles into the soft ground by using a pile driving equipment or in-situ drilling and then pouring concrete to form concrete piles in the soft ground; the piles of the circular pile-group are selected from a group consisting of Larsen steel sheet piles, steel precast piles or concrete piles, wherein the concrete piles are bored concrete piles or precast concrete piles.

S3: constructing the ring beam 220 and roof plate 230 on the top of the piles of the circular pile-group 210, or constructing the ring beam 220 on the top of the piles of the circular pile-group 210 and connecting it with the base 110. | Wherein, the step S3 during constructing the newly-built wind power foundation comprising: S301: providing multi-layer shear nails on the top of the piles of the circular pile-group 210 or providing protruded embedded steel bars extended upwards of 20cm-50cm from the top of the piles of the circular pile-group 210;

S302: binding the steel bars of the ring beam, which are located on the top of the piles of the circular pile-group 210, and binding the steel bars of the roof plate inside the ring beam; providing a plurality of protruded steel joints, extending toward the axis of the ring beam, from the preset installation position on the inner wall of the ring beam 220 for connecting the ring beam with the reinforcement members; providing a plurality of protruded steel joints, extending upwardly, from the preset installation position of the roof plate 230 for connecting the roof plate 230 with the pillar 240; S303: building formworks of the ring beam and the roof plate, pouring concrete in the formworks so as to form the ring beam 220 and the roof plate 230, and pouring the shear nails or the protruded embedded steel bars so as to make the ring beam 220 and the roof plate 230 into a whole.

Wherein, the step S3 during constructing the expanded wind power foundation comprising: S301: providing multi-layer shear nails on the top of the piles of the circular pile-group 210 or providing protruded embedded steel bars extended upwards of 20cm-50cm from the top of the piles of the circular pile-group 210; and performing roughing treatment and embedding bars to the round edges or polygonal corner surfaces of the base to be connected to the ring beam 220; S302: binding the steel bars of the ring beam 220, which are located on the top of the piles of the circular pile-group 210; providing a plurality of protruded steel joints, extending toward the axis of the ring beam, from the preset installation position on the inner wall of the ring beam 220 for connecting the ring beam 220 with the reinforcement members 250; providing a plurality of protruded steel joints, extending upwardly, from the preset installation position of the base 110 for connecting the roof plate 230 with the pillar 240; S303: building formwork of the ring beam 220, pouring concrete in the formwork and pouring the shear nails or the embedded bars so as to make the ring beam 220 and the base 110 into a whole.

S4: constructing the pillar 240 axially on the roof plate 230 or the platform

120.

Wherein, the step S4 during constructing the newly-built wind power foundation comprising: S401: constructing steel bars of the pillar 240 axially on the roof plate 230; : binding the steel bars inside the pillar 240 and connecting with the reserved steel joints of the roof plate 230; meanwhile, providing a plurality of protruded steel joints, extending outward from the preset installation position of the side wall of the pillar 240 for connecting the side wall of the pillar with the reinforcement members 250; $402: building a formwork of the pillar, pouring concrete into the formwork so as to form the pillar 240.

Wherein, the step S4 during constructing the expanded wind power foundation comprising: S401: constructing steel bars of the pillar 240 axially on the platform 120; performing roughing treatment and embedding bars to side wall of the platform 120 and the partial surface of the base 110; and then binding the steel bars inside the pillar 240 and connecting with the embedded bars of the base 110; meanwhile, providing a plurality of protruded steel joints, extending outward from the preset installation position of the side wall of the pillar 240 for connecting the side wall of the pillar with the reinforcement members 250; | S402: building a formwork of the pillar 240, pouring concrete into the formwork so as to form the pillar 240.

S5: constructing a plurality of reinforcement members 250 for supporting the pillar and transmit the load thereof along the circumferential direction of the side wall of the pillar; wherein: S501: binding the steel bars inside the reinforcement members 250 and connecting with the protruded steel joints of the ring beam 220 and the protruded steel joints of the pillar 240, respectively; S502: building formworks of the reinforcement members 250, pouring concrete in the formworks so as to form the reinforcement members 250.

S6: providing the foundation ring 260 and the anchor plate 242 at the top and bottom of the ring structure of the pillar 240, respectively, and then fixing the foundation ring 260 and the anchor plate 242 on the ring structure 241 via bolts and nuts so as to complete the construction of the newly-built or expanded wind power foundation structure.

Optionally, in steps 3, 4, 5, the construction of the ring beam, roof plate, pillar and the reinforcement members adopt the following construction steps: providing multi-layer shear nails on the top of the piles of the circular pile- group 210 or providing protruded embedded steel bars extended upwards of 20cm-50cm from the top of the piles of the circular pile-group 210; meanwhile during the construction of the expanded wind power foundation, it is further required to performing roughing treatment and embedding bars to the round edges or polygonal corner surfaces of the base to be connected to the ring beam; binding the steel bars of the ring beam, the roof plate, the pillars and the reinforcement members, and reserving steel joints for each component to connect with other component; building formworks of the ring beam, the roof plate, the pillars and the reinforcement members; pouring concrete in the formworks, and connecting the ring beam, the roof plate, the pillars and the reinforcement members as a whole by shear nails.

Optionally, in steps 3,4,5, the ring beam, the roof plate, the pillar and the reinforcement members are prefabricated or partially prefabricated on land, all the prefabricated ring beam, the roof plate, the pillar and the reinforcement members are reserved with steel joints for connecting with each other; and then the prefabricated components are transported to the installation site, and the prefabricated components are connected with each other by the reserved steel joints, and then the joints are casted with concrete so as to complete the construction of ring beam, the roof plate, the pillar and the reinforcement members.

The present invention is to build a newly-built or expanded wind power foundation structure on soft ground, which being build under following sequence from bottom to top: arranging the circular pile-group in the soft ground or around the existing wind power foundation, providing the ring beam on the top of the circular pile-group, providing the roof plate inside the ring beam or surrounding the existing base by the ring beam, providing the pillar on the roof plate or the base, and providing reinforcement members between the ring beam and the pillar for supporting the pillar and transmit the load thereof, and then providing the foundation ring on the pillar for fixing the tower so as to complete the construction of the new or expanded wind power foundation and use the wind power foundation for fixing the tower, thus meeting the actual needs of construction of newly-built or expanded wind power foundation on soft ground; The present invention combines the advantages of traditional expanded foundation and cylindrical foundation, and is a novel pile-group cylindrical foundation structure formed by adding steel sheet piles or concrete piles on the periphery of traditional foundation; by using this construction method, the expanded foundation and the existing foundation are connected as a whole through the ring beam, the present invention makes full use of the top cover pressure of the expanded foundation and the active and passive earth pressure of the side wall of the existing cylindrical foundation to resist the large bending moment load generated during the operation of the wind turbine, which improves the bearing capacity of the foundation structure; the wind farms adopted the newly-built and or expanded foundation according to the present invention can fully utilize the land resources, reduce the land occupation area, reduce the resource occupation cost, avoid rock-socketed piling or complicated foundation treatment before construction, thus improving the constructing efficiency and effectively using the existing wind power foundation, having the advantages of safe, econornic, efficient and convenient, can effectively improve the economic benefits of the enterprise and obtain better social benefits

The forgoing description is just a preferred embodiment of the present invention and is not intended to limit the present invention.

Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention. :

Claims (9)

' LU102092 CLAIMS

1. A newly-built wind power foundation on soft ground, characterized in that the foundation includes the following from bottom to top: a circular pile-group, a ring beam, a roof plate, a pillar, a plurality of reinforcement members and a foundation ring; the circular pile-group including more than four piles, one end of each pile extends into the soft ground, while the other end is connected with the ring beam, and the side walls of the pile are contacted with the side walls of the adjacent piles; the ring beam being arranged on the top of the piles of the circular pile- group, and is in contact with the top of the piles; the roof plate being arranged along the circumferential direction of the inner side of the ring beam, and the outer peripheral side wall of the roof plate being at least partially connected with the inner peripheral side wall of the ring beam; | the pillar being axially arranged on the upper part of the roof plate, and a | foundation ring being arranged on the top of the pillar for the installation of the tower of the wind turbine; a plurality of reinforcement members being circumferentially arranged on the side wall of the pillar, one end of each reinforcement member being connected with the side wall of the pillar, and the other end being connected with the ring beam; wherein the reinforcement members are used to support the pillar and transmit the load thereof.

2. An expanded wind power foundation on soft ground, the expanded foundation refers to an expanded foundation built on the existing wind power foundation on soft ground; and the existing wind power foundation includes a base and a platform arranged on the base, characterized in that the expanded foundation includes the following from bottom to top: A circular pile-group, a ring beam, a pillar, a plurality of reinforcement members and a foundation ring;

the circular pile-group being arranged along the outer periphery of the base, which includes more than four piles, one end of each pile extends into the soft ground, while the other end is connected with the ring beam, and the side walls of the pile are contacted with the side walls of the adjacent piles; the ring beam being arranged on the top of the piles of the circular pile- group, and is in contact with the top of the piles; the base being arranged in the inner side of the ring beam, and the outer peripheral side wall of the base is at least partially connected with the inner peripheral side wall of the ring beam; the pillar being sleeved on the side wall of the platform, the top of the pillar is fixed with a foundation ring for the installation of the tower of the wind turbine: | the vertical distance from the top of the pillar to the top of the platform is in the range of 1m-3m; a plurality of reinforcement members being circumferentially arranged on the side wall of the pillar, one end of each reinforcement member being connected with the side wall of the pillar, and the other end being connected with the ring beam; wherein the reinforcement members are used to support | the pillar and transmit the load thereof.

3. The newly-built or expanded wind power foundation according to claim 1 or claim 2, characterized in that the reinforcement members include a plurality of pairs of radial supports and cant beams, wherein one end of the radial support is connected to the bottom of the side wall of the pillar, and the other end is connected to the inner wall of the ring beam; one end of the cant beam is connected to the upper part of the side wall of the pillar, and the other end is connected to the connection part of the ring beam and the radial support.

4. The newly-built or expanded wind power foundation according to claim 1 or claim 2, characterized in that the pillar is a hollow cylinder with a ring structure at its top, and a cavity is formed beneath the ring structure, and the foundation ring and the tower installed on the foundation ring are in detachable connection with the ring structure.

5. The newly-built or expanded wind power foundation according to claim 1 or claim 2, characterized in that the piles of the circular pile-group are selected from a group consisting of Larsen steel sheet piles, steel precast piles or concrete piles, wherein the concrete piles are bored concrete piles or precast concrete piles; the ring beam is a reinforced concrete beam.

6. The newly-built or expanded wind power foundation according to claim 5, characterized in that when the piles of the circular pile-group are Larsen steel sheet piles or steel precast piles, multi-layer shear nails are provided on the top of the piles; and when the piles of the circular pile-group are concrete piles, the top of the concrete piles have protruded embedded steel bars. |

7. A construction method for a newly-built or expanded wind power foundation structure on soft ground according to claim 1 or claim 2, characterized in that the method comprising: according to the load parameters of the wind turbine and the ground bearing capacity of the soft ground where the wind power foundation to be built or expanded, determining the type of the piles of the circular pile-group, calculating the penetration depth of the piles, and determining the surrounding area of the circular pile-group and the construction parameters for constructing the wind power foundation; constructing the circular pile-group, the ring beam, the pillar, the reinforcement members and the foundation ring sequentially from bottom to top in the soft ground; wherein, the piles of the circular pile-group are constructed in the following manner: piling a plurality of piles into the soft ground by using a pile driving equipment or in-situ drilling and then pouring concrete to form concrete piles in

| LU102092 the soft ground; wherein the side walls of each pile are contacted with the side walls of the adjacent piles.

8. The construction method according to claim 7, characterized in that the ring beam, the roof plate, the pillar and the reinforcement members are constructed by the following steps: providing multi-layer shear nails on the top of the piles or providing protruded embedded steel bars extended upwards of 20cm-50cm from the top of the piles; during the construction of the expanded wind power foundation, it is further required to performing roughing treatment and embedding bars to the round edges or polygonal corner surfaces of the base to be connected to the ring beam; binding the steel bars of the ring beam, the roof plate, the pillar and the reinforcement members, and reserving steel joints for each component to connect with other component; building formworks of the ring beam, the roof plate, the pillar and the reinforcement members; pouring concrete in the formworks, and connecting the ring beam, the roof plate, the pillar and the reinforcement members as a whole by shear nails.

9. The construction method according to claim 7 or claim 8, characterized in that the ring beam, the roof plate, the pillar and the reinforcement members are prefabricated or partially prefabricated on land, all the prefabricated ring beam, the roof plate, the pillar and the reinforcement members are reserved with steel joints for connecting with each other; and then the prefabricated components are transported to the installation site, and the prefabricated components are connected with each other by the reserved steel joints, and then the joints are casted with concrete so as to complete the construction of ring beam, the roof plate, the pillar and the reinforcement members.