CN-121976555-A - Pile-anchor combined land fan foundation structure and checking calculation method

CN121976555ACN 121976555 ACN121976555 ACN 121976555ACN-121976555-A

Abstract

The invention discloses a pile-anchor combined land fan foundation structure and a checking calculation method. The structure comprises a circular table type expansion foundation, a grouting anchor rod structure and a prefabricated circular tube pile group, wherein a connection mode of a foundation ring and an anchor bolt is adopted for being connected with a fan, light concrete is filled in the foundation ring to reduce the self weight of the expansion foundation, light sand concrete is filled in the prefabricated circular tube pile to reduce the self weight of a pile body, elastic pile shoes capable of elastically stretching and contracting are arranged at the pile bottom to reduce the influence of soil layer deformation on the fan foundation, and the pile anchor composite mode is adopted to improve the pulling resistance of the fan foundation. According to the checking method, pulling resistance and bearing capacity are checked for the pile-anchor composite type fan foundation structure, impact resistance cutting checking is performed for an expanded foundation, and local bearing checking is performed for the contact position of an expanded foundation anchor bolt and concrete. The expansion foundation part of the invention has lighter weight, good deformation resistance and pulling resistance, and can be used for land fan construction under all geological conditions.

Inventors

XU QIAN
ZHOU ZHUOWEN
ZHU HAITAO
SU JUNSHENG

Assignees

天津大学

Dates

Publication Date: 20260505
Application Date: 20260213

Claims (10)

1. The pile-anchor composite land fan foundation structure is characterized by comprising a circular table type expansion foundation, a grouting anchor rod structure and a prefabricated circular pipe pile group; The round platform type expansion foundation comprises configuration steel bars, a foundation ring, common concrete, light concrete and a prestress anchor bolt assembly which are arranged in the round platform type expansion foundation, wherein the configuration steel bars form a framework of the round platform type expansion foundation, the foundation ring is arranged at the middle lower part of the round platform type expansion foundation, the upper part of the foundation ring is connected with a fan structure through the prestress anchor bolt assembly, the light concrete is poured in the foundation ring, and the common concrete is poured in the rest part of the round platform type expansion foundation; the grouting anchor rod structure comprises a plurality of circumferentially arranged mortar foundations and anchor rod bundles, one ends of the anchor rod bundles are embedded into the mortar foundations, and the other ends of the anchor rod bundles are connected with the foundation ring; The precast circular pipe pile group comprises a plurality of precast concrete circular pipe piles and elastic pile shoes which are circumferentially distributed, light sand concrete is filled in the precast concrete circular pipe piles, the elastic pile shoes are connected to the bottoms of the precast concrete circular pipe piles through sealing welding, and the tops of the precast concrete circular pipe piles are rigidly connected with the circular truncated cone type extension foundation.
2. The pile-anchor composite land fan foundation structure of claim 1, wherein the foundation ring comprises an upper flange, a lower flange and a ring body connecting the upper flange and the lower flange, wherein a backing plate and a bolt cap are welded on the bottom end surface of the upper flange at the flange hole of the upper flange in sequence, and the lower flange is connected with the anchor rod bundle at the flange hole of the lower flange through a nut.
3. The pile-anchor composite land fan foundation structure of claim 2, wherein the inner side and the outer side of the ring body are respectively provided with a hidden beam, a plurality of side round holes are circumferentially formed in the ring body, radial, transverse and longitudinal three-layer perforated steel bars are arranged in the side round holes in a penetrating mode, a plurality of upper round holes are circumferentially formed in the upper flange, a plurality of lower round holes are circumferentially formed in the lower flange, the upper round holes correspond to the lower round holes one to one, and vertical perforated steel bars are arranged between the upper round holes and the lower round holes in a penetrating mode.
4. The pile-anchor composite land wind turbine foundation structure of claim 1, wherein the pre-stressed anchor assembly comprises a pre-stressed anchor that is sheathed with a PVC plastic pipe.
5. The pile-anchor composite land draught fan foundation structure of claim 4, wherein said prestressed anchor assemblies are peripherally provided with an indirect rebar grid.
6. A pile-anchor composite land wind turbine foundation structure as defined in claim 1, wherein the anchor tendons comprise steel strands and steel tendon bulbs, the anchor tendons being anchored in the mortar foundation by the steel tendon bulbs.
7. The pile-anchor composite land fan foundation structure of claim 1, wherein said elastic pile shoe comprises an inner sleeve, an outer sleeve and a spring, wherein two ends of said spring are respectively connected with said inner sleeve and said outer sleeve, and are connected with said outer sleeve and said inner sleeve by welding.
8. The pile-anchor composite land fan foundation structure of claim 7, wherein a plurality of pin heads are circumferentially arranged on the wall of the inner sleeve, grooves are correspondingly arranged on the wall of the outer sleeve, and the pin heads can freely slide in the grooves.
9. An inspection method based on the pile-anchor composite land-based fan foundation structure as set forth in any one of claims 1-8, and characterized by comprising the following inspection contents of carrying out inspection for the bearing capacity of the pile-anchor composite land-based fan foundation structure, inspection for the pulling resistance of the pile-anchor composite land-based fan foundation structure, impact-resistant cutting inspection for a circular table type expansion foundation and partial bearing inspection for the contact position of a prestressed anchor bolt and concrete of the circular table type expansion foundation.
10. The method of checking a pile-anchor composite land wind turbine foundation structure of claim 9, wherein, The bearing capacity of the pile-anchor combined land fan foundation structure is checked and calculated, and the concrete steps are as follows: obtaining an axial force N, a horizontal force V and a bending moment M which are transmitted from the upper fan to the upper top surface of the lower foundation structure under the basic combination, and further calculating the minimum value of the axial force born by the pile top of the single precast concrete round pipe pile And axial force maximum Calculating the minimum axial force at the end of the anchor rod bundle Calculating the vertical ultimate bearing capacity of a single precast concrete round pipe pile according to the geological parameters of the soil layer of the field If and only if ≤ The bearing capacity checking calculation is passed; checking and calculating the pulling resistance of the pile-anchor combined land fan foundation structure, wherein the pulling resistance is as follows: If it is >0 And 0, If not, not performing pulling resistance checking calculation, designing the prestressed anchor bolt according to the structural requirement, if <0 Or <0, Calculating the pulling resistance of the single precast concrete round pipe pile And pullout resistance of individual anchor beams If and only if < 、 < When the two kinds of the components are satisfied at the same time, checking the pulling resistance to meet the requirement; Impact resistance cutting checking calculation is carried out on a circular table type expansion foundation, and the method is specifically as follows: firstly, performing impact resistance cutting checking calculation on a variable-order part of a truncated cone type expansion foundation to obtain a punching force design value of the basic combination Then calculating the design value of the die-cut bearing capacity of the round table type expansion foundation according to the die-cut bearing capacity formula of the concrete If it meets < The impact resistance and cutting checking calculation at the variable-order position of the truncated cone-shaped expanded foundation meets the requirements, checking calculation is carried out on the impact resistance and cutting resistance of the diagonal pile, and the design value of the cutting force of the basic combination is calculated Design value of die-cut bearing capacity of concrete If it meets < The corner pile impact resistance, cutting and checking calculation meet the requirements; The method is characterized by comprising the following steps of checking and calculating local bearing of the contact part of the prestressed anchor bolt and the concrete of the circular table type expanded foundation: calculating partial pressure according to the stress of the top of the basic combination lower round table type expansion foundation Then calculating the local bearing resistance under the combined action of the indirect reinforcing mesh and the concrete in the local compression area according to the local bearing formula Ultimate bearing capacity If (if) > The size of the prestressed anchor bolt backing plate is enlarged or the label of the ordinary concrete poured outside the foundation ring is increased, if the requirements are met at the same time < And < And the local bearing checking calculation meets the requirement.

Description

Pile-anchor combined land fan foundation structure and checking calculation method Technical Field The invention relates to the field of wind power plants, in particular to a pile-anchor combined land fan foundation structure and an inspection method. Background Wind power generation is the most promising way of development scale and commercial development in various renewable energy utilization technologies, is a national important green energy investment project, and plays an important role in the national economic development of China. At present, china mainly has two forms of an onshore fan and an offshore fan, and the onshore fan gradually develops along with the wide application of wind power, but in areas with poor engineering characteristics such as cohesive soil, silt and filling soil, the natural foundation cannot meet the construction requirements of a fan foundation, and needs to construct a foundation form suitable for places with poor engineering geological conditions. The pile foundation is adopted, the foundation pile is stressed, and the large bending moment load of the wind turbine generator is converted into the vertical load of the foundation pile, so that the bearing capacity of the foundation can be effectively improved. However, in order to meet the requirement of bearing capacity of foundation piles, the traditional pile foundation needs to be provided with a plurality of foundation piles and poured with bearing platforms for combined action, and the problems of large engineering quantity, large earth excavation quantity, high overall construction cost and the like exist. Along with the application of the large-capacity wind turbine generator, popularization of a novel mixed foundation form and reduction of the manufacturing cost of a fan foundation become an important technical requirement under the wind power development background of the low price age. Disclosure of Invention Aiming at the problems of large engineering quantity, large earth excavation quantity, high overall construction cost and the like of the existing land fan foundation, the invention provides the pile-anchor composite land fan foundation structure and the checking method. In order to achieve the above purpose, the invention adopts the following technical scheme: A pile-anchor composite land fan foundation structure comprises a truncated cone type expansion foundation, a grouting anchor rod structure and a prefabricated circular pipe pile group; The round platform type expansion foundation comprises configuration steel bars, a foundation ring, common concrete, light concrete and a prestress anchor bolt assembly which are arranged in the round platform type expansion foundation, wherein the configuration steel bars form a framework of the round platform type expansion foundation, the foundation ring is arranged at the middle lower part of the round platform type expansion foundation, the upper part of the foundation ring is connected with a fan structure through the prestress anchor bolt assembly, the light concrete is poured in the foundation ring, and the common concrete is poured in the rest part of the round platform type expansion foundation; the grouting anchor rod structure comprises a plurality of circumferentially arranged mortar foundations and anchor rod bundles, one ends of the anchor rod bundles are embedded into the mortar foundations, and the other ends of the anchor rod bundles are connected with the foundation ring; The precast circular pipe pile group comprises a plurality of precast concrete circular pipe piles and elastic pile shoes which are circumferentially distributed, light sand concrete is filled in the precast concrete circular pipe piles, the elastic pile shoes are connected to the bottoms of the precast concrete circular pipe piles through sealing welding, and the tops of the precast concrete circular pipe piles are rigidly connected with the circular truncated cone type extension foundation. The foundation ring comprises an upper flange, a lower flange and a ring body for connecting the upper flange and the lower flange, wherein a backing plate and a bolt cap are welded on the bottom end face of the upper flange at the position of a flange hole of the upper flange in sequence, and the lower flange is connected with the anchor rod bundle at the position of the flange hole of the lower flange through a nut. Still further, the inside and outside of ring body all is provided with the hidden girder, and a plurality of side round hole is seted up to the ring body circumference, wears to establish radial, horizontal, vertical three-layer perforation reinforcing bar in the side round hole, upward the flange circumference sets up a plurality of round hole, and lower flange circumference sets up a plurality of round hole down, goes up the round hole and goes up the round hole one-to-one with lower round hole, wears to establish vertical perforation reinforcing bar between going up the round h