Construction method for mass concrete structure of wind power foundation

Abstract

The wind power foundation mass concrete structure construction method comprises the following steps that S1, a foundation pit is excavated, specifically, the foundation pit needed by a wind power foundation is excavated in a target place; s2, a formwork is erected, and a supporting formwork is erected in the foundation pit according to construction requirements; s3, reinforcing steel bars are bundled according to construction requirements; s4, temperature measuring points are arranged, the temperature measuring points are arranged at the designed positions, and temperature measuring lines are pre-buried; and S5, concrete pouring is conducted, specifically, pouring is conducted in sequence in different areas, real-time temperature measurement is conducted in the pouring process, and temperature control and moisture preservation are conducted well. According to the method, through tight temperature monitoring and a reasonable pouring mode, the problem of structural cracking in the pouring process can be effectively avoided.

Description

Technical Field

[0001] This invention relates to the field of engineering construction technology, specifically to a construction method for large-volume concrete structures for wind power foundations. Background Technology

[0002] The wind turbine foundation is the base of the wind turbine tower, bearing its entire weight and undertaking all stresses, including support, earthquake resistance, and resistance to strong winds. Its sturdiness and durability play a crucial role in the safe and stable operation of the wind turbine, directly determining its survival.

[0003] The characteristics of wind turbine concrete structures are their large size and volume, classifying them as mass-produced concrete. Furthermore, they are exposed to humid or water-contact environments for extended periods. In addition to meeting strength requirements, they must also possess excellent durability and impermeability. Moreover, due to the large cement content per unit volume of mass-produced concrete, hydration heat and shrinkage can easily cause structural cracking, leading to structural damage. Controlling the temperature during concrete pouring is a major challenge in construction. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, this invention proposes a construction method for large-volume concrete structures for wind power foundations. Through strict temperature monitoring and reasonable pouring methods, structural cracking during the pouring process can be effectively avoided.

[0005] To achieve the above objectives, the present invention provides a construction method for a large-volume concrete structure for wind power foundations, comprising the following steps: S1: Excavate the foundation pit, excavate the foundation pit required for the wind power foundation at the target site; S2: Erect formwork, and build supporting formwork in the foundation pit according to construction requirements; S3: Reinforcement, binding steel bars according to construction requirements; S4: Set up temperature measurement points, arrange the temperature measurement points at the designed locations, and pre-embed the temperature measurement wires; S5: Concrete pouring, pouring in the designated areas in sequence, monitoring the temperature in real time during the pouring process, and ensuring proper temperature control and moisture retention.

[0006] Furthermore, in step S1, the foundation pit includes a trapezoidal cross-section at the bottom and a rectangular cross-section at the top. The top of the trapezoidal cross-section has the same width as the bottom of the rectangular cross-section, and a concrete cushion layer is provided at the bottom of the foundation pit.

[0007] Furthermore, in step S2, the outer side of the support template is close to the inner wall of the foundation pit, and the inner side of the support template encloses the cavity inside the wind power foundation.

[0008] Furthermore, in step S3, the reinforcing bars of the annular wall portion of the wind power foundation include several vertical bars, ring bars, and longitudinal bars. The ring bars are arranged around the circumference, the longitudinal bars are arranged radially on the horizontal plane, and the vertical bars are set vertically. The reinforcing bars of the cantilever slab portion of the wind power foundation include several vertical bars, ring bars, and diagonal bars. The reinforcing bars at the bottom of the wind power foundation include two layers of mesh reinforcing bars, with several upright reinforcing bars between the two layers of mesh reinforcing bars.

[0009] Furthermore, a pre-reserved pipe is provided in the suspended part inside the wind turbine foundation ring wall, and prestressing tendons are provided in the pre-reserved pipe. The prestressing tendons are evenly distributed in the circumference of the wind turbine foundation. The prestressing tendons include embedded steel pipes. The top of the embedded steel pipe protrudes from the top of the wind turbine foundation ring wall. An anchor plate is provided at the bottom of the embedded steel pipe. Spiral reinforcement is sleeved on the embedded steel pipe and connected to the anchor plate. The top of the embedded steel pipe is inclined towards the inside of the wind turbine foundation ring wall. One side of the wedge-shaped surface of the anchor plate faces downward. The thickness of the side of the anchor plate closest to the inside of the wind turbine foundation ring wall is less than the thickness of the other side.

[0010] Furthermore, the top surface of the wind turbine foundation has an annular top surface groove located inside the prestressing tendons. Several pre-embedded positioning parts are provided in the top surface groove. The positioning pre-embedded parts are evenly distributed along the top surface groove and are set at the bottom of the top surface groove. The positioning pre-embedded parts are used to position the concrete tower of the wind turbine equipment.

[0011] Further, step S4 includes the following steps: S401: Arrange temperature measurement points. Temperature measurement points are set at the junction of the suspended part of the wind turbine foundation ring wall, the middle of the wind turbine foundation cantilever slab, and the bottom of the wind turbine foundation. Three temperature measurement points are set at each location, one at the top, one at the middle, and one at the bottom. S402: Determine the depth of the temperature measurement point. The upper temperature measurement point is located within 50mm below the concrete surface, the middle temperature measurement point is located at the center of the concrete thickness, and the lower temperature measurement point is located within 50mm above the bottom surface of the concrete. S403: Select a suitable temperature sensing wire, and extend the length of the temperature sensing wire by more than 200mm from the depth of the temperature sensing point; S404: Pre-embed the temperature measuring wire, tie the temperature measuring wire to the steel bar, and before pouring concrete, tie the steel bar with the temperature measuring wire to the main reinforcement of the foundation. The temperature sensor is located at the temperature measuring point, and the plug is left outside the concrete and covered with a plastic bag to avoid moisture and keep it clean.

[0012] Furthermore, in step S5, the wind power foundation is divided into a first block, a second block, and a third block from bottom to top. The horizontal direction is advanced in parallel, and the vertical direction adopts a continuous pouring method of diagonal layering, thin layer pouring, natural flow, sequential advancement, and one-time completion. The concrete moist curing time shall not be less than 28 days, and water shall be sprayed no less than twice a day to ensure that the concrete surface is in a moist state.

[0013] Furthermore, the temperature of the concrete was monitored from the start of pouring, including the entire process of the internal temperature of the concrete rising, cooling, approaching the ambient temperature, and entering a safe range after the insulation layer was removed. Temperature was measured 6 times per day for the first 3 days, and 4 times per day after the 3 days, with the monitoring period lasting for 14 days.

[0014] Furthermore, in step S5, the temperature control parameters include: The concrete pouring temperature should be between 5℃ and 30℃. The temperature rise of the concrete pouring body from the initial pouring temperature shall not exceed 50℃. The temperature difference between the inside and outside of the concrete pouring body shall not exceed 25℃. The cooling rate of the concrete pouring body shall not exceed 2℃ / d; When removing the insulation cover, the temperature difference between the surface of the concrete pouring body and the ambient temperature should not exceed 20℃.

[0015] The construction method for large-volume concrete structures for wind power foundations of the present invention is applicable to large-volume concrete structures. Through strict temperature monitoring and reasonable pouring methods, structural cracking during the pouring process can be effectively avoided. Attached Figure Description

[0016] The invention will now be further described and explained with reference to the accompanying drawings.

[0017] Figure 1 This is a schematic diagram of the overall structure of the wind power foundation according to the preferred embodiment of the present invention.

[0018] Figure 2 This is a schematic diagram of the steel reinforcement in a wind turbine foundation.

[0019] Figure 3 This is a plan view of a wind turbine foundation.

[0020] Figure 4 This is a structural schematic diagram used to illustrate prestressed tendons.

[0021] Figure 5 This is a diagram showing the sequence of concrete pouring in step 5.

[0022] Attached reference numerals: 1. Wind turbine foundation; 11. Vertical reinforcement; 12. Circular reinforcement; 13. Longitudinal reinforcement; 14. Diagonal reinforcement; 15. Mesh reinforcement; 16. Stirrup reinforcement; 17. Subbase; 21. Prestressed tendons; 22. Anchor plate; 23. Spiral reinforcement; 24. Annular groove; 25. Embedded positioning component; 3. Temperature measuring point. Detailed Implementation

[0023] The technical solution of the present invention will be more clearly and completely explained below with reference to the accompanying drawings and through the description of preferred embodiments of the present invention.

[0024] A preferred embodiment of the present invention provides a construction method for a large-volume concrete structure of a wind power foundation, comprising the following steps: S1: Excavate the foundation pit. Excavate the foundation pit required for wind power foundation 1 at the target site.

[0025] S2: Erect formwork. Erect supporting formwork in the foundation pit according to construction requirements.

[0026] S3: As Figure 2 As shown, reinforcement is provided, and the steel bars are tied according to construction requirements.

[0027] S4: As Figure 1 As shown, set temperature measurement point 3, arrange temperature measurement point 3 at the designed location, and pre-embed temperature measurement wire; S401: Arrange temperature measurement points 3. Temperature measurement points 3 are respectively set at the junction of the suspended part of the ring wall of the wind power foundation 1, the middle of the cantilever plate of the wind power foundation 1, and the bottom of the wind power foundation 1. Each temperature measurement point 3 is set up with three points in total, one at the top, one at the middle, and one at the bottom. S402: Determine the depth of temperature measuring point 3. The upper temperature measuring point 3 is located within 50mm below the concrete surface, the middle temperature measuring point 3 is located at the center of the concrete thickness, and the lower temperature measuring point 3 is located within 50mm above the bottom surface of the concrete. S403: Select a suitable temperature sensing wire, and extend the length of the temperature sensing wire by more than 200mm from the depth of temperature sensing point 3; S404: Pre-embed the temperature measuring wire, tie the temperature measuring wire to the steel bar, and before pouring concrete, tie the steel bar with the temperature measuring wire to the main reinforcement of the foundation. The temperature sensor is located at temperature measuring point 3. The plug is left outside the concrete and covered with a plastic bag to avoid moisture and keep it clean.

[0028] S5: Concrete pouring, pouring in the designated areas in sequence, monitoring the temperature in real time during the pouring process, and ensuring proper temperature control and moisture retention.

[0029] Specifically, in step S1, the foundation pit includes a trapezoidal cross-section at the bottom and a rectangular cross-section at the top. The top of the trapezoidal cross-section has the same width as the bottom of the rectangular cross-section, and a concrete cushion layer 17 is provided at the bottom of the foundation pit.

[0030] In step S2, the outer side of the support template is close to the inner wall of the foundation pit, and the inner side of the support template encloses the cavity inside the wind power foundation 1.

[0031] In step S3, as Figure 2As shown, the reinforcing bars of the annular wall portion of the wind power foundation 1 include several vertical bars 11, ring bars 12, and longitudinal bars 13. The ring bars 12 are arranged around the circumference, the longitudinal bars 13 are arranged radially on the horizontal plane, and the vertical bars 11 are set vertically. The reinforcing bars of the cantilever slab portion of the wind power foundation 1 include several vertical bars 11, ring bars 12, and diagonal bars 14. The reinforcing bars at the bottom of the wind power foundation 1 include two layers of mesh reinforcing bars 15, and several upright reinforcing bars 16 are provided between the two layers of mesh reinforcing bars 15.

[0032] like Figure 3 and Figure 4 As shown, a pre-reserved pipe is provided in the suspended part inside the annular wall of the wind turbine foundation 1. The pre-stressed tendons 21 are provided in the pre-reserved pipe. The pre-stressed tendons 21 are evenly distributed in the circumference of the wind turbine foundation 1. The pre-stressed tendons 21 include embedded steel pipes. The top of the embedded steel pipes protrudes from the top of the annular wall of the wind turbine foundation 1. An anchor plate 22 is provided at the bottom of the embedded steel pipes. Spiral reinforcement 23 is sleeved on the embedded steel pipes. The spiral reinforcement 23 is connected to the anchor plate 22. The top of the embedded steel pipes is inclined towards the inner side of the annular wall of the wind turbine foundation 1. One side of the wedge-shaped surface of the anchor plate 22 faces downward. The thickness of the side of the anchor plate 22 closest to the inner side of the annular wall of the wind turbine foundation 1 is less than the thickness of the other side.

[0033] like Figure 3 and Figure 4 As shown, the top surface of the wind power foundation 1 has an annular top surface groove located inside the prestressing tendon 21. Several pre-embedded positioning parts 25 are provided in the top surface groove. The positioning pre-embedded parts are evenly distributed along the top surface groove and are set at the bottom of the top surface groove. The positioning pre-embedded parts are used to position the concrete tower of the wind turbine equipment.

[0034] In step S4, a building electronic thermometer is used for temperature measurement. This instrument is a professional temperature measuring instrument developed according to the construction characteristics and relevant technical specifications of the national construction industry. It can display the measured temperature intuitively, accurately, and quickly, and has high reliability, a wide range of applications, wide operating temperature range, small size, light weight, and simple operation. The instrument consists of a main unit and temperature measuring wires. The main unit is a portable instrument equipped with a power switch, a lighting switch, a socket, and an LCD screen, which can digitally display the measured temperature value. The temperature measuring wires are pre-embedded and are made of a plug, wires, and a temperature sensor. Each temperature measuring wire can measure the temperature of one point. When measuring the temperature, press the main unit's power switch, insert the temperature measuring wire plug into the main unit's socket, and the main unit's display screen will show the temperature of the corresponding measuring point 3.

[0035] In step S5, as Figure 5As shown, the wind turbine foundation is divided into three sections from bottom to top: the first section, the second section, and the third section. Horizontally, the pouring is parallel, while vertically, a continuous pouring method is used, employing diagonal layering, thin-layer pouring, natural flow, sequential advancement, and a one-time completion. During pouring, direct impact of concrete onto the formwork is strictly prohibited to prevent significant damage. Vibration must also be strictly controlled, with precise timing to prevent over-vibration, which could cause formwork misalignment, and to prevent under-vibration, which could result in inadequate bonding and become weak points. The concrete must be kept moist for at least 28 days, with watering at least twice daily to ensure the concrete surface remains consistently moist.

[0036] The temperature of the concrete was monitored from the start of pouring, including the entire process of internal temperature rise, fall, approaching ambient temperature, and removal of the insulation layer, entering a safe range. Temperature was measured 6 times per 24 hours for the first 3 days, and 4 times per 24 hours thereafter, for a total of 14 days. Temperature control indicators included: concrete pouring temperature between 5℃ and 30℃; temperature rise of the concrete pouring body from the pouring temperature not exceeding 50℃; temperature difference between the inner and outer surfaces of the concrete pouring body not exceeding 25℃; cooling rate of the concrete pouring body not exceeding 2℃ / day; and temperature difference between the surface of the concrete pouring body and the ambient temperature when removing the insulation layer not exceeding 20℃.

[0037] The above-described specific embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Various modifications, substitutions, and improvements made by those skilled in the art to the technical solutions of the present invention based on the provided textual description and drawings, without departing from the design concept and spirit of the present invention, should all fall within the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

Claims

1. A construction method for large-volume concrete structures for wind turbine foundations, characterized in that, Includes the following steps: S1: Excavate the foundation pit, excavate the foundation pit required for the wind power foundation at the target site; S2: Erect formwork, and build supporting formwork in the foundation pit according to construction requirements; S3: Reinforcement, binding steel bars according to construction requirements; S4: Set up temperature measurement points, arrange the temperature measurement points at the designed locations, and pre-embed the temperature measurement wires; S5: Concrete pouring, pouring in the designated areas in sequence, monitoring the temperature in real time during the pouring process, and ensuring proper temperature control and moisture retention.

2. The construction method for a large-volume concrete structure for wind power foundations according to claim 1, characterized in that, In step S1, the foundation pit includes a trapezoidal cross-section at the bottom and a rectangular cross-section at the top. The top of the trapezoidal cross-section has the same width as the bottom of the rectangular cross-section, and a concrete cushion layer is provided at the bottom of the foundation pit.

3. The construction method for a large-volume concrete structure for wind power foundations according to claim 2, characterized in that, In step S2, the outer side of the support template is close to the inner wall of the foundation pit, and the inner side of the support template encloses the cavity inside the wind power foundation.

4. The construction method for a large-volume concrete structure for wind power foundations according to claim 1, characterized in that, In step S3, the reinforcing bars of the ring wall portion of the wind power foundation include several vertical bars, ring bars, and longitudinal bars. The ring bars are arranged around the circumference, the longitudinal bars are arranged radially on the horizontal plane, and the vertical bars are set vertically. The reinforcing bars of the cantilever slab portion of the wind power foundation include several vertical bars, longitudinal bars, and diagonal bars. The reinforcing bars at the bottom of the wind power foundation include two layers of mesh reinforcing bars, with several upright reinforcing bars between the two layers of mesh reinforcing bars.

5. The construction method for a large-volume concrete structure for wind power foundations according to claim 4, characterized in that, The suspended portion inside the wind turbine foundation ring wall is provided with a reserved pipe, and a prestressing tendon is provided inside the reserved pipe. The prestressing tendons are evenly distributed equidistantly in the circumference of the wind turbine foundation. The prestressing tendon includes a pre-embedded steel pipe, the top of which protrudes from the top of the wind turbine foundation ring wall. An anchor plate is provided at the bottom of the pre-embedded steel pipe. A spiral reinforcement is sleeved on the pre-embedded steel pipe and connected to the anchor plate. The top of the pre-embedded steel pipe is inclined towards the inside of the wind turbine foundation ring wall. One side of the wedge-shaped surface of the anchor plate faces downward. The thickness of the side of the anchor plate closest to the inside of the wind turbine foundation ring wall is less than the thickness of the other side.

6. The construction method for a large-volume concrete structure for wind power foundations according to claim 5, characterized in that, The top surface of the wind turbine foundation has an annular groove inside the prestressing tendons. Several pre-embedded positioning components are provided in the top surface groove. The positioning components are evenly distributed along the top surface groove and are set at the bottom of the groove. The positioning components are used to position the concrete tower of the wind turbine equipment.

7. The construction method for a large-volume concrete structure for wind power foundations according to claim 1, characterized in that, Step S4 includes the following steps: S401: Arrange temperature measurement points. Temperature measurement points are set at the junction of the suspended part of the wind turbine foundation ring wall, the middle of the wind turbine foundation cantilever slab, and the bottom of the wind turbine foundation. Three temperature measurement points are set at each location, one at the top, one at the middle, and one at the bottom. S402: Determine the depth of the temperature measurement point. The upper temperature measurement point is located within 50mm below the concrete surface, the middle temperature measurement point is located at the center of the concrete thickness, and the lower temperature measurement point is located within 50mm above the bottom surface of the concrete. S403: Select a suitable temperature sensing wire, and extend the length of the temperature sensing wire by more than 200mm from the depth of the temperature sensing point; S404: Pre-embed the temperature measuring wire, tie the temperature measuring wire to the steel bar, and before pouring concrete, tie the steel bar with the temperature measuring wire to the main reinforcement of the foundation. The temperature sensor is located at the temperature measuring point, and the plug is left outside the concrete and covered with a plastic bag to avoid moisture and keep it clean.

8. The construction method for a large-volume concrete structure for wind power foundations according to claim 1, characterized in that, In step S5, the wind power foundation is divided into a first block, a second block, and a third block from bottom to top. The horizontal direction is advanced in parallel, and the vertical direction adopts a continuous pouring method of oblique layering, thin layer pouring, natural flow, sequential advancement, and one-time completion. The concrete moist curing time shall not be less than 28 days, and water shall be sprinkled no less than twice a day to ensure that the concrete surface is in a moist state.

9. A construction method for a large-volume concrete structure for wind power foundations according to claim 8, characterized in that, The temperature of the concrete was monitored from the start of pouring, including the entire process of the internal temperature of the concrete rising, cooling, approaching the ambient temperature, and entering a safe range after the insulation layer was removed. The temperature was measured 6 times per day for the first 3 days, and 4 times per day after the 3 days, with the monitoring period lasting for 14 days.

10. A construction method for a large-volume concrete structure for wind power foundations according to claim 9, characterized in that, In step S5, the temperature control parameters include: The concrete pouring temperature should be between 5℃ and 30℃. The temperature rise of the concrete pouring body from the initial pouring temperature shall not exceed 50℃. The temperature difference between the inside and outside of the concrete pouring body shall not exceed 25℃. The cooling rate of the concrete pouring body shall not exceed 2℃ / d; When removing the insulation cover, the temperature difference between the surface of the concrete pouring body and the ambient temperature should not exceed 20℃.

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