Winter construction method for secondary grouting of fan foundation in alpine region

Abstract

The invention discloses a winter construction method for secondary grouting of a fan foundation in an alpine region, and relates to the technical field of winter construction of wind power station foundations. The winter construction method for secondary grouting of the fan foundation in the alpine region comprises the following steps that S1, a heat preservation shed is built at the position of the fan foundation to limit an operation space; s2, heat supply equipment and a temperature measurement assembly are arranged in the working space, and the environment in the working space is heated; s3, a grouting material is prepared, secondary grouting is conducted on the fan foundation, the grouting work needs to be conducted continuously, and primary grouting is completed; s4, when the grouting material reaches the grouting height, the grouting surface is slightly troweled and flattened, and the exposed grouting part is subjected to heat preservation and moisture locking treatment; and S5, the grouting formwork is dismantled, and concrete is cured. According to the winter construction method for secondary grouting of the fan foundation in the alpine region, the pouring effect of secondary grouting can be guaranteed, cracks on a grouting component are reduced, the engineering attractiveness is improved, and the engineering quality is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of winter construction of wind power station foundations, and in particular to a winter construction method for secondary grouting of wind turbine foundations in high-cold areas. Background Art

[0002] Secondary grouting materials are key items in the construction of wind power projects. Generally, materials with higher strength and early strength enhancement blocks are used. However, the volume of secondary grouting is extremely small and is easily affected by the surrounding environment, especially the ambient temperature. This is especially true when construction is carried out in winter in high-altitude cold areas. Because the climate conditions in high-altitude cold areas are relatively cold in winter, during the construction process, traditional pouring methods are easily affected by environmental factors. After the concrete is exposed to the external cold environment, the temperature drops rapidly, which will reduce the fluidity of the self-compacting concrete and make it impossible to ensure dense pouring. After the pouring is completed, the grouting components will have extension or even through cracks, which will affect the appearance of the project and cannot guarantee the quality of the project. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention proposes a winter construction method for secondary grouting of a wind turbine foundation in a high-cold area. The winter construction method for secondary grouting of a wind turbine foundation in a high-cold area can ensure the pouring effect of the secondary grouting, reduce the generation of cracks on the grouting components, improve the aesthetics of the project and ensure the quality of the project.

[0005] The secondary grouting winter construction method for a wind turbine foundation in a high-cold region according to an embodiment of the present invention comprises the following steps:

[0006] S1: Build a heat preservation shed at the foundation of the fan, and limit the working space for secondary grouting in the heat preservation shed;

[0007] S2: Install heating equipment and temperature measurement components in the working space to heat the working space environment and make the temperature in the working space not lower than 15°C, and heat the foundation contact surface and grouting template contact surface in the slurry pouring space to make the temperature not lower than 10°C;

[0008] S3: Use water with a temperature of not less than 30℃ and not more than 65℃ to prepare grouting materials, and perform secondary grouting on the fan foundation. The grouting work needs to be carried out continuously and completed in one grouting.

[0009] S4: When the grouting material reaches the pouring height, the grouting surface is lightly smoothed and the exposed part of the grouting is treated with heat preservation and moisture lock;

[0010] S5: Remove the grouting formwork and cure the concrete.

[0011] The winter construction method for secondary grouting of a wind turbine foundation in a high-cold region according to the embodiment of the present invention can ensure the pouring effect of the secondary grouting, reduce the generation of cracks on the grouting components, improve the aesthetics of the project and ensure the quality of the project.

[0012] In some embodiments, in step S3, when preparing the grouting material, a vertical mixer is used, and first half of the grouting material and all the water in the corresponding batch are added for stirring. After stirring evenly, the other half of the grouting material is added for stirring. After all the grouting material is stirred evenly, the steel fiber is added and stirred evenly.

[0013] In some embodiments, when preparing the grouting material, the ratio of the grouting material, water and steel fiber is 25:2.875:0.375.

[0014] In some embodiments, the heating equipment includes multiple air heaters, which are arranged at intervals along the circumference of the air heater base, and an air supply pipe is connected to the air supply end of at least one air heater, and the air supply pipe is surrounded around the circumference of the air heater base, and the warm air discharged from the air heater is transported to the ground through the air supply pipe.

[0015] In some embodiments, one end of the air supply pipe away from the heater is blocked, and a plurality of air supply holes are opened on the air supply pipe along the extension direction so that the air supply holes face the ground.

[0016] In some embodiments, in step S3, when the slurry is poured, the grouting material is poured in from a single input port, a grouting booster is used to push the drainage along the bottom of the slurry flow direction during the grouting process, and a leather hammer is used to appropriately knock the upper anchor plate during the grouting process.

[0017] In some embodiments, in step S3, before the secondary grouting, the concrete surface in contact with the grouting material should be roughened to ensure that the roughened surface of the concrete is fully moistened within 24 hours before grouting, and the accumulated water is removed 1 hour before grouting. When the secondary grouting is performed on the fan foundation, the temperature of the foundation contact surface and the grouting template contact surface in the slurry pouring space is not lower than 15°C.

[0018] In some embodiments, in step S1, before building the insulation shed, a circular installation pit is dug along the periphery of the fan foundation, a supporting frame is fixed in the installation pit, and an insulation quilt is fixed on the supporting frame so that multiple quilts are tightly overlapped without leaks, and an insulation plastic sheet is applied to the inner surface of the quilt so that the bottom of the quilt and the insulation plastic sheet are buried in the installation pit.

[0019] In some embodiments, a self-limiting temperature electric heating tape is installed on a supporting frame corresponding to the thermal insulation plastic sheet, and the self-limiting temperature electric heating tape is laid on the floor of the working space.

[0020] In some embodiments, in step S4, the exposed grouting part is first tightly covered with a plastic film, and then covered with cotton cloth for heat preservation, and / or,

[0021] In step S5, during the concrete curing period, the internal temperature of the working space is monitored and adjusted in real time for 24 hours to ensure that the curing environment temperature is not lower than 20°C. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a flow chart of a winter construction method for secondary grouting of a wind turbine foundation in a high-cold region according to an embodiment of the present invention. DETAILED DESCRIPTION

[0023] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0024] like Figure 1 As shown, the secondary grouting winter construction method for wind turbine foundation in high-cold areas of the embodiment of the present invention comprises the following steps:

[0025] S1: Build a heat preservation shed at the foundation of the fan, and limit the working space for secondary grouting in the heat preservation shed;

[0026] S2: Install heating equipment and temperature measurement components in the working space to heat the working space environment and make the temperature in the working space not lower than 15°C, and heat the foundation contact surface and grouting template contact surface in the slurry pouring space to make the temperature not lower than 10°C;

[0027] S3: Use water with a temperature of not less than 30℃ and not more than 65℃ to prepare grouting materials, and perform secondary grouting on the fan foundation. The grouting work needs to be carried out continuously and completed in one grouting.

[0028] S4: When the grouting material reaches the pouring height, the grouting surface is lightly smoothed to ensure the flatness of the grouting component, close the shrinkage and dehydration cracks on the initial surface, and perform insulation and moisture-locking treatment on the exposed grouting part;

[0029] S5: Remove the grouting formwork and cure the concrete.

[0030] The winter construction method for secondary grouting of wind turbine foundations in high-cold areas according to an embodiment of the present invention sets up a heat-insulating shed to limit the working space used for pouring the wind turbine foundation. An environment suitable for slurry pouring can be created by heating the working space. By heating the working space and increasing the temperature of the foundation contact surface and the grouting template contact surface, the grouting material after the secondary grouting is easily solidified, thereby ensuring the pouring effect of the secondary grouting, reducing the occurrence of cracks on the grouting components, improving the aesthetics of the project and ensuring the quality of the project.

[0031] Specifically, the secondary grouting of the wind turbine foundation needs to be completed uninterruptedly within 2 hours at one time to minimize the heat loss of the grouting during the mixing and pouring process, and the temperature entering the mold is maintained at no less than 15°C. By controlling the temperature of the water body, after the water body and the grouting material are mixed, the water body and the grouting material are heat exchanged to increase the temperature of the stirred slurry, further prevent frost damage, and reduce the temperature difference hazards caused by the heat of cement hydration, ensure the initial fluidity of the slurry, facilitate the pouring of the slurry, and at the same time provide a good foundation for maintenance and reducing the occurrence of cracks.

[0032] In some embodiments, in step S3, when preparing the grouting material, a vertical mixer is used. According to the set ratio, half of the grouting material and all the water in the corresponding batch are first added and stirred. After stirring evenly, the other half of the grouting material is added and stirred. After all the grouting materials are stirred evenly, steel fibers are added and stirred evenly.

[0033] The addition of an appropriate amount of steel fiber and its random distribution after stirring can effectively hinder the expansion of microcracks inside the grouting material and the formation of macrocracks, significantly improve the tensile, bending, impact and fatigue resistance of the grouting material, and have good ductility.

[0034] In some embodiments, when configuring the grouting material, the ratio of the grouting material, water and steel fiber is 25:2.875:0.375, so that the initial fluidity of the slurry obtained is 295 mm, and the vertical expansion rate is 0.2%, so that the key indicators such as the actual strength, fluidity and micro-expansion of the slurry all reach the effects during the trial mixing, laying a good foundation for the pouring and maintenance of the secondary grouting, and reducing the crack length of the structure itself.

[0035] In some embodiments, the heating equipment includes multiple air heaters, which are arranged at intervals along the circumference of the fan foundation, and an air supply pipe is connected to the air supply end of at least one of the air heaters, and the air supply pipe is surrounded around the circumference of the fan foundation. The warm air discharged from the heater is transported to the ground through the air supply pipe, and the flow direction of the warm air is constrained by the air supply pipe, and an annular belt exchange zone is formed around the fan foundation to heat up the foundation in the belt exchange zone, and to heat up the foundation contact surface and the grouting template contact surface in the slurry pouring space.

[0036] Optionally, the air heater may be an air heater that uses electricity as energy, or an air heater that uses diesel as energy, or both types of air heaters.

[0037] In some embodiments, one end of the air supply pipe away from the heater is blocked, and a plurality of air supply holes are opened on the air supply pipe along the extension direction so that the air supply holes face the ground.

[0038] Specifically, two rows of air supply holes are arranged circumferentially along the air supply duct, and the air supply duct is placed on the ground. The two rows of air supply holes are respectively located on both sides of the belt exchange zone. When the heater is working, the warm air is transported to the corresponding ground through the air supply holes to exchange heat and heat the ground around the fan foundation, thereby creating conditions for heating the foundation contact surface and the grouting template contact surface in the slurry pouring space, and the operation is convenient and reliable.

[0039] In some embodiments, in step S3, when the slurry is poured, the grouting material is poured in from a single input port to prevent the entrainment of air and water. Vibration is strictly prohibited during the grouting process. A grouting booster is used to push the drainage along the bottom of the slurry flow direction to ensure the fluidity and compaction effect of the grouting. During the grouting process, a leather hammer is used to appropriately knock the upper anchor plate to eliminate bubbles on the surface of the plate and make the grouting material filling more dense.

[0040] In some embodiments, the temperature measurement assembly includes multiple environmental thermometers and temperature guns. The multiple environmental thermometers are hung symmetrically in the working space. The temperature of the foundation contact surface and the grouting template contact surface is detected by the temperature gun. The working space is measured at multiple points by the multiple environmental thermometers to ensure that the temperature in the working space meets the grouting regulation. The temperature of the foundation contact surface and the grouting template contact surface is measured by a movable temperature gun to ensure the grouting effect.

[0041] In some embodiments, in step S3, before the secondary grouting, the concrete surface in contact with the grouting material should be roughened to ensure that the roughened surface of the concrete is fully moistened within 24 hours before grouting, and the accumulated water is removed 1 hour before grouting to ensure the connection effect between the secondary pouring structure and the original concrete structure. When the fan foundation is subjected to secondary grouting, the temperature of the foundation contact surface and the grouting template contact surface in the slurry pouring space is not lower than 15°C, providing a suitable condensation temperature for the grouting after pouring, facilitating the rapid condensation of the grouting, ensuring the structural quality after the grouting condensation, and effectively reducing the occurrence of cracks.

[0042] In some embodiments, in step S1, before building the insulation shed, a circular installation pit is dug along the side of the fan foundation, a supporting frame is fixed in the installation pit, and an insulation quilt is fixed on the supporting frame so that multiple quilts are tightly overlapped without leaks, and an insulation plastic sheet is applied to the inner surface of the quilt. After the quilt and the insulation plastic sheet are installed, the installation pit is backfilled so that the bottom of the quilt and the insulation plastic sheet are buried in the installation pit.

[0043] By setting up the installation pit, it is convenient to fix and seal the bottom of the thermal insulation quilt and the thermal insulation plastic sheet, thereby reducing the heat loss in the thermal insulation shed from the contact point between the thermal insulation quilt and the ground. At the same time, the thermal insulation quilt part and the thermal insulation plastic sheet part in the installation pit can form an annular isolation and insulation belt, which is convenient for the thermal insulation and heating operations in the thermal insulation shed. Insulation is carried out through the quilt, and thermal insulation plastic sheet is set on the inside of the thermal insulation quilt, which can further reduce the heat exchange of the air inside and outside the thermal insulation shed, thereby ensuring that the temperature in the working space is much higher than the ambient temperature outside the thermal insulation shed.

[0044] In some embodiments, a self-limiting temperature electric heating tape is installed on a supporting frame corresponding to the thermal insulation plastic sheet, and the self-limiting temperature electric heating tape is laid on the floor of the working space.

[0045] Specifically, the self-limiting temperature electric heating belt is laid along a spiral ring on the ground of the working space, and a set distance is set between two adjacent ring belts. A protective plate is placed through the distance, and a working platform for personnel to walk and place equipment is formed above the self-limiting temperature electric heating belt through the protective plate to prevent personnel or equipment from causing damage to the self-limiting temperature electric heating belt.

[0046] By setting up a self-limiting temperature electric heating tape, the heating temperature can be automatically limited, and the output power can be automatically adjusted according to the temperature of the heated object to prevent overheating. It is safe and reliable, and can be shortened or extended within a certain length range, saving insulation materials, easy to use and maintain, and saving electricity.

[0047] In some embodiments, in step S4, the exposed grouting part is first covered tightly with a plastic film to keep condensed water in the plastic film, and then covered with cotton cloth for insulation to ensure moisture retention and temperature locking after the secondary grouting is completed.

[0048] In some embodiments, in step S5, during concrete curing, the internal temperature of the working space is monitored and adjusted in real time for 24 hours to ensure that the curing environment temperature is not lower than 20°C, thereby ensuring that the ambient temperature during concrete curing meets the requirements to reduce the occurrence of cracks after concrete solidification.

[0049] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0051] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0052] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0053] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0054] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A secondary grouting winter construction method for wind turbine foundation in high-cold areas, characterized in that: The following steps are involved: S1: Build a heat preservation shed at the foundation of the fan, and limit the working space for secondary grouting in the heat preservation shed; S2: Install heating equipment and temperature measurement components in the working space to heat the working space environment and make the temperature in the working space not lower than 15°C, and heat the foundation contact surface and grouting template contact surface in the slurry pouring space to make the temperature not lower than 10°C; S3: Use water with a temperature of not less than 30℃ and not more than 65℃ to prepare grouting materials, and perform secondary grouting on the fan foundation. The grouting work needs to be carried out continuously and completed in one grouting. S4: When the grouting material reaches the pouring height, the grouting surface is lightly smoothed and the exposed part of the grouting is treated with heat preservation and moisture lock; S5: Remove the grouting formwork and cure the concrete.

2. The secondary grouting winter construction method for wind turbine foundation in high-cold areas according to claim 1 is characterized in that: In step S3, when preparing the grouting material, a vertical mixer is used. First, half of the grouting material and all the water in the corresponding batch are added and stirred. After stirring evenly, the other half of the grouting material is added and stirred. After all the grouting materials are stirred evenly, the steel fiber is added and stirred evenly.

3. The secondary grouting winter construction method for wind turbine foundation in high-cold areas according to claim 2 is characterized in that: When preparing the grouting material, the ratio of grouting material, water and steel fiber is 25:2.875:0.

375.

4. The secondary grouting winter construction method for wind turbine foundation in high-cold areas according to claim 1 is characterized in that: The heating equipment includes multiple air heaters, which are arranged at intervals along the circumference of the fan base, and an air supply pipe is connected to the air supply end of at least one of the air heaters. The air supply pipe is surrounded around the circumference of the fan base, and the warm air discharged from the heater is transported to the ground through the air supply pipe.

5. The secondary grouting winter construction method for wind turbine foundation in high-cold areas according to claim 4 is characterized in that: The end of the air supply pipe away from the heater is blocked, and a plurality of air supply holes are opened on the air supply pipe along the extension direction so that the air supply holes face the ground.

6. The secondary grouting winter construction method for wind turbine foundation in high-cold areas according to claim 1 is characterized in that: In step S3, when the grout is poured, the grout is poured in from a single input port, and a grouting booster is used to push the drainage along the bottom of the slurry flow direction during the grouting process, and a leather hammer is used to appropriately knock the upper anchor plate during the grouting process.

7. The secondary grouting winter construction method for wind turbine foundation in high-cold areas according to claim 1 is characterized in that: In step S3, before the secondary grouting, the concrete surface in contact with the grouting material should be roughened to ensure that the roughened concrete surface is fully moistened within 24 hours before grouting, and the accumulated water is removed 1 hour before grouting. When the secondary grouting is performed on the fan foundation, the temperature of the foundation contact surface and the grouting template contact surface in the slurry pouring space shall not be lower than 15°C.

8. The secondary grouting winter construction method for wind turbine foundation in high-cold areas according to claim 1 is characterized in that: In step S1, before building the insulation shed, a circular installation pit is dug along the side of the fan foundation, a supporting frame is fixed in the installation pit, and an insulation quilt is fixed on the supporting frame so that multiple quilts are tightly overlapped without leaks, and an insulation plastic sheet is applied to the inner surface of the quilt so that the bottom of the quilt and the insulation plastic sheet are buried in the installation pit.

9. The secondary grouting winter construction method for wind turbine foundation in high-cold areas according to claim 8 is characterized in that: A self-limiting temperature electric heating tape is installed on the supporting frame corresponding to the thermal insulation plastic sheet, and the self-limiting temperature electric heating tape is laid on the ground of the working space.

10. The secondary grouting winter construction method for wind turbine foundation in high-cold areas according to claim 1 is characterized in that: In step S4, the exposed grouting part is firstly covered tightly with a plastic film, and then covered with cotton cloth for heat preservation, and / or, In step S5, during the concrete curing period, the internal temperature of the working space is monitored and adjusted in real time for 24 hours to ensure that the curing environment temperature is not lower than 20°C.

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