Construction method of tower pile foundation in frozen earth region

Abstract

The disclosure provides a construction method of a tower pile foundation in a frozen soil area, and relates to the technical field of photovoltaics. The construction method comprises the following steps: selecting a target frozen soil area, and forming a pile foundation hole in the target frozen soil area by using a rotary drilling rig dry hole forming technology; controlling the temperature of the concrete during transportation of the concrete to maintain the concrete at a first preset temperature; controlling the temperature of the environment around the pile foundation hole during pouring of the pile foundation in the pile foundation hole to maintain the environment around the pile foundation hole at a second preset temperature; controlling the temperature of the concrete poured in the pile foundation hole during pouring of the pile foundation in the pile foundation hole to maintain the concrete poured in the pile foundation hole at a third preset temperature; after the concrete in the pile foundation hole is poured, the temperature of the concrete in the pile foundation hole and the environment around the pile foundation hole is controlled for a preset time; and after the concrete in the pile foundation hole is poured, the pile foundation hole is backfilled with frozen soil having a temperature difference with the frozen soil temperature of the target frozen soil area within a preset temperature range.

Description

Technical Field

[0001] This disclosure relates to the field of photovoltaic technology, and more specifically, to a construction method for tower pile foundations in permafrost regions. Background Technology

[0002] With the transformation of the global energy structure, photovoltaic power generation, as a clean and renewable energy form, has been widely used around the world. Because it takes place in regions such as the Gobi Desert and other arid areas, which have abundant sunshine resources, it provides a good foundation for photovoltaic power generation.

[0003] However, when fixing iron towers and photovoltaic power generation equipment, it is necessary to set up stable and reliable pile foundations for the iron towers and photovoltaic power generation equipment in areas such as the Gobi Desert and deserts.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this disclosure is to provide a construction method for iron tower pile foundations in permafrost regions.

[0006] According to one aspect of this disclosure, a construction method for steel tower pile foundations in permafrost regions is provided, the method comprising: Select a target frozen soil area, and use rotary drilling rig dry drilling technology to form pile foundation holes in the target frozen soil area; Temperature control is implemented during concrete transportation to maintain the concrete at a first preset temperature. During the process of pouring the pile foundation in the pile foundation hole, the temperature of the environment around the pile foundation hole is controlled so that the environment around the pile foundation hole is maintained at a second preset temperature. During the process of pouring the pile foundation in the pile foundation hole, the concrete poured in the pile foundation hole is temperature controlled so that the concrete poured in the pile foundation hole is maintained at a third preset temperature. After the concrete in the pile foundation hole is poured, the temperature of the concrete in the pile foundation hole and the surrounding environment is controlled for a preset time. After the concrete in the pile foundation hole is poured, the pile foundation hole is backfilled with frozen soil whose temperature difference with the frozen soil in the target frozen soil area is within a preset temperature range.

[0007] In one exemplary embodiment of this disclosure, after the concrete pouring in the pile foundation hole is completed, the pile foundation hole is backfilled with frozen soil whose temperature difference with the frozen soil of the target frozen soil area is within a preset temperature range, including: When the pile foundation hole is formed in the target frozen soil area, the frozen soil excavated to form the pile foundation hole is temperature controlled so that the temperature difference between the excavated frozen soil and the frozen soil in the target frozen soil area is within a preset temperature range. After the concrete in the pile foundation hole is poured, the excavated frozen soil is used for backfilling.

[0008] In one exemplary embodiment of this disclosure, the excavated frozen soil is temperature-controlled using an air-cooling device.

[0009] In one exemplary embodiment of this disclosure, after the concrete pouring in the pile foundation hole is completed, the pile foundation hole is backfilled with frozen soil whose temperature difference with the frozen soil of the target frozen soil area is within a preset temperature range, including: Frozen soil is excavated around the pile foundation hole in the target frozen soil area. After the concrete in the pile foundation hole is poured, the frozen soil excavated around the pile foundation hole is used to backfill the pile foundation hole.

[0010] In one exemplary embodiment of this disclosure, during the process of pouring the pile foundation in the pile foundation hole, temperature control is performed on the concrete poured into the pile foundation hole, including: A heating structure is installed inside the pile foundation hole, and then concrete is poured into the pile foundation hole. The temperature of the concrete poured into the pile foundation hole is controlled by the heating structure.

[0011] In one exemplary embodiment of this disclosure, the heating structure includes an electric heating element disposed in the pile foundation hole, the concrete poured in the pile foundation hole covers the electric heating element, and the electric heating element controls the temperature of the concrete poured in the pile foundation hole.

[0012] In one exemplary embodiment of this disclosure, the heating structure includes a cylindrical heating element, and concrete is poured into the cylindrical heating element to form a concrete pile foundation; The cylindrical heating element is equipped with an electric heating element, which controls the temperature of the concrete poured into the pile foundation hole.

[0013] In one exemplary embodiment of this disclosure, the electric heating element includes a reinforcing bar, and the heating structure further includes a current controller, which is connected to the reinforcing bar and controls the heat generation of the reinforcing bar.

[0014] In one exemplary embodiment of this disclosure, temperature control of the concrete during transportation includes: Concrete is transported using a hopper, and heating and insulation components are installed on the hopper to maintain the concrete in the hopper at the first preset temperature.

[0015] In one exemplary embodiment of this disclosure, during the process of casting the pile foundation in the pile foundation hole, temperature control is performed on the environment surrounding the pile foundation hole, including: An insulated room is built in the target permafrost area, and the insulated room serves as the insulated room for the pouring construction area. Heating equipment and temperature detection equipment are installed in the insulation room to maintain the temperature of the insulation room at a second preset temperature.

[0016] The technical advantages of the construction method for iron tower pile foundations in permafrost regions disclosed in this paper are as follows: I. Dry drilling using rotary drilling rigs eliminates the need for mud slurry wall protection. Relying on the cutting and squeezing action of the rotary drilling bucket, the frozen soil is directly cut into the hole, while the weight of the bucket itself and its rotational force maintain the stability of the hole wall. Since no external mud slurry is introduced, the problem of wall protection failure caused by mud freezing is avoided, effectively preventing hole wall collapse and ensuring that key parameters such as hole diameter, depth, and verticality meet design requirements, laying a solid foundation for subsequent concrete pouring and pile formation. Furthermore, during dry drilling, only the frozen soil in the target area is cut and removed, without altering the physical and mechanical properties of the surrounding frozen soil, avoiding problems such as frozen soil thawing and strength reduction caused by mud infiltration. The removed frozen soil can also be used for backfilling the pile foundation hole, achieving resource recycling, reducing construction waste, and meeting environmental protection requirements. In desert and Gobi areas where water resources are scarce, wet drilling requires large amounts of water to prepare the mud slurry, while dry drilling requires no water, perfectly adapting to the resource situation in these areas and reducing construction costs and difficulty. In addition, rotary drilling rigs offer fast dry drilling speed and a high degree of automation. Compared with traditional manual or wet drilling, they can significantly shorten drilling time and improve construction efficiency. They are especially suitable for winter construction in permafrost areas (where temperatures are extremely low, water resources are frozen, and wet drilling is not feasible), ensuring that construction progress is not limited by the season.

[0017] II. The strength formation of concrete depends on the hydration reaction, and the rate of the hydration reaction is closely related to temperature. Excessively high or low temperatures can lead to uneven hydration, affecting the uniformity and stability of concrete strength. Temperature control ensures that concrete is maintained at a suitable initial preset temperature (e.g., 5℃-25℃, dynamically adjusted according to ambient temperature) during transportation, guaranteeing a smooth hydration reaction and preventing reduced fluidity and premature setting due to excessively low temperatures. This ensures that the concrete can be smoothly poured and densely fill the pile foundation holes after arrival at the construction site, reducing pouring defects such as honeycomb, pitting, and voids, and guaranteeing the quality of pile foundation formation. Furthermore, in winter construction scenarios with frozen soil, temperature control prevents concrete from freezing during transportation, ensuring normal hydration and guaranteeing that the concrete's strength and durability meet design requirements. In addition, the diurnal temperature range in desert and Gobi regions can reach over 20℃, and the temperature difference between winter and summer can exceed 60℃. Traditional concrete transportation methods cannot adapt to such extreme temperature changes, easily leading to fluctuations in concrete quality. This disclosure allows for dynamic adjustment of the first preset temperature based on ambient temperature, adapting to temperature changes in different seasons and time periods, ensuring stable quality during concrete transportation, and improving the adaptability and reliability of construction.

[0018] Third, in desert and Gobi regions, the large diurnal temperature range means that excessive temperature fluctuations during pouring can cause rapid changes in the concrete surface temperature while the internal temperature changes more slowly, creating a temperature difference between the inside and outside and leading to surface shrinkage cracks. By controlling the ambient temperature to maintain a stable second preset temperature, temperature fluctuations are reduced, excessive temperature differences between the inside and outside of the concrete are avoided, surface cracks are prevented, and the quality of concrete pouring is guaranteed. The hydration reaction of concrete is affected not only by its own temperature but also by the external ambient temperature. If the external ambient temperature is too low, it will inhibit the hydration reaction, resulting in slow strength growth; if the temperature is too high, it will accelerate the hydration reaction, easily leading to cracks. By controlling the ambient temperature to the second preset temperature, stable external conditions are provided for the concrete hydration reaction, ensuring its normal progress and guaranteeing normal strength growth.

[0019] Fourth, by controlling the temperature of the concrete inside the borehole and maintaining a third preset temperature (which matches the first preset temperature to ensure the continuity of concrete temperature and avoid sudden temperature changes), the internal temperature distribution of the concrete becomes uniform, reducing the temperature difference between the inside and outside and effectively inhibiting the formation of temperature cracks. Especially in permafrost areas, where the temperature inside the borehole is low, temperature control can prevent the hydration reaction from stalling due to excessively low concrete temperature, while also preventing the heat released by the hydration reaction from accumulating and causing the internal temperature to become too high, thus achieving a dynamic balance of concrete temperature. Furthermore, in winter permafrost construction scenarios, the low temperature inside the borehole slows down the concrete hydration reaction and strength gain, leading to prolonged curing time and impacting the construction cycle. By controlling the temperature of the concrete inside the borehole, the concrete temperature is increased, accelerating the hydration reaction, promoting rapid strength gain, shortening curing time, and consequently shortening the overall construction cycle and reducing construction costs.

[0020] Fifth, by continuously controlling the temperature, the concrete and its surrounding environment are maintained within a suitable temperature range, ensuring that the hydration reaction proceeds fully and steadily, allowing the concrete strength to gradually increase and ultimately meet the design requirements, satisfying the load-bearing capacity of the pile foundation. Especially in frozen soil regions, continuous temperature control prevents the concrete from freezing, ensuring the normal progress of the hydration reaction and avoiding insufficient strength. Simultaneously, after pouring, the concrete is in a shrinkage phase; temperature fluctuations exacerbate shrinkage and cause cracks. Continuous temperature control maintains temperature stability, reducing the impact of temperature fluctuations on concrete shrinkage, effectively inhibiting the formation of shrinkage and temperature cracks, improving the integrity and durability of the concrete, and extending the service life of the tower pile foundation. A stable temperature environment reduces stress concentration within the concrete, preventing crack propagation and further ensuring the quality of the pile foundation. Furthermore, continuous temperature control accelerates the concrete hydration reaction, shortens curing time, and consequently shortens the overall construction cycle. Continuous temperature control also avoids concrete quality problems caused by improper curing, reducing rework and re-piling costs, and lowering the overall construction cost.

[0021] VI. The temperature difference between the backfill frozen soil and the target area frozen soil is controlled within a preset range (e.g., within ±2℃, which can be adjusted according to the actual frozen soil temperature). This avoids heat transfer caused by excessive temperature difference, prevents the surrounding frozen soil from melting and the backfill frozen soil from freezing, reduces the generation of temperature stress, avoids cracking and settlement of the backfill layer, ensures the stability of the backfill layer, and thus guarantees the overall stability of the pile foundation. Simultaneously, the backfill frozen soil and the surrounding frozen soil have consistent physical and mechanical properties and similar temperatures, allowing them to quickly fuse and form an integral load-bearing structure. This improves the bonding strength between the backfill layer and the surrounding frozen soil, enhances the pile foundation's pull-out and overturning resistance, and meets the requirements of the tower pile foundation to withstand various loads. The integrated backfill layer can effectively disperse the load on the pile foundation and transfer it to the surrounding frozen soil, improving the bearing efficiency of the pile foundation. In addition, once the backfilled frozen soil forms a whole with the surrounding frozen soil, it can adapt to the temperature changes in the frozen soil area, and shrink and expand synchronously with the temperature changes. This avoids pile foundation displacement and settlement caused by the deformation difference between the backfill layer and the frozen soil, ensuring the long-term stability of the iron tower and photovoltaic power generation equipment pile foundation, and extending the service life of the iron tower and photovoltaic power generation equipment pile foundation.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0024] Figure 1 This is a flowchart illustrating a construction method for a steel tower pile foundation in a frozen soil region, as provided in one embodiment of this disclosure.

[0025] Figure 2 This is a flowchart of temperature control for concrete during transportation, provided as an embodiment of the present disclosure.

[0026] Figure 3 This is a flowchart illustrating temperature control of the environment surrounding the pile foundation hole during the pouring of the pile foundation in the pile foundation hole, as provided in one embodiment of the present disclosure.

[0027] Figure 4 This is a flowchart illustrating temperature control of the concrete poured into the pile foundation hole during the process of pouring a pile foundation in the pile foundation hole, as provided in one embodiment of the present disclosure.

[0028] Figure 5This is a flowchart illustrating an embodiment of the present disclosure of backfilling pile foundation holes with frozen soil whose temperature difference with the target frozen soil area is within a preset temperature range.

[0029] Figure 6 This is a flowchart illustrating another embodiment of the present disclosure, showing the backfilling of pile foundation holes with frozen soil whose temperature difference with the target frozen soil area is within a preset temperature range. Detailed Implementation

[0030] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided to make this disclosure more comprehensive and complete, and to fully convey the concept of example embodiments to those skilled in the art. The described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of embodiments of this disclosure. However, those skilled in the art will recognize that the technical solutions of this disclosure can be practiced with one or more of these specific details omitted, or other methods, apparatus, steps, etc., can be employed. In other instances, well-known technical solutions are not shown or described in detail to avoid obscuring various aspects of this disclosure.

[0031] Furthermore, the accompanying drawings are merely illustrative of this disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. The terms “a,” “an,” “the,” and “the” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and mean that additional elements / components / etc. may exist in addition to those listed; the terms “first,” “second,” etc., are used only as labels and are not a limitation on the number of objects.

[0032] Against the backdrop of global energy structure transformation, photovoltaic power generation is widely used in areas with abundant solar resources, such as the Gobi Desert and other desert regions. These areas require the installation of pile foundations to fix the towers and photovoltaic power generation equipment. However, there are two major technical challenges in desert and Gobi areas: first, the large temperature difference leads to poor quality of concrete after solidification (such as cracks and insufficient strength); second, the thawing of permafrost during construction damages the stability of the pile foundation, thereby affecting its bearing capacity, shortening the service life of the tower cover and the photovoltaic power generation equipment pile foundation, and even causing safety hazards.

[0033] In response, this disclosure provides a construction method for steel tower pile foundations in permafrost regions, such as... Figure 1As shown, it includes: Step S100: Select the target frozen soil area and form pile foundation holes in the target frozen soil area using dry drilling technology with rotary drilling rig; Step S200: Temperature control is performed on the concrete during transportation to maintain the concrete at a first preset temperature. Step S300: During the process of pouring the pile foundation in the pile foundation hole, the temperature of the environment around the pile foundation hole is controlled so that the environment around the pile foundation hole is maintained at a second preset temperature. Step S400: During the process of pouring the pile foundation in the pile foundation hole, the concrete poured in the pile foundation hole is temperature controlled so that the concrete poured in the pile foundation hole is maintained at the third preset temperature. Step S500: After the concrete in the pile foundation hole is poured, the temperature of the concrete in the pile foundation hole and the surrounding environment is controlled for a preset time. Step S600: After the concrete pouring in the pile foundation hole is completed, the pile foundation hole is backfilled with frozen soil whose temperature difference with the frozen soil in the target frozen soil area is within the preset temperature range.

[0034] The technical advantages of the construction method for iron tower pile foundations in permafrost regions disclosed in this paper are as follows: I. Dry drilling using rotary drilling rigs eliminates the need for mud slurry wall protection. Relying on the cutting and squeezing action of the rotary drilling bucket, the frozen soil is directly cut into the hole, while the weight of the bucket itself and its rotational force maintain the stability of the hole wall. Since no external mud slurry is introduced, the problem of wall protection failure caused by mud freezing is avoided, effectively preventing hole wall collapse and ensuring that key parameters such as hole diameter, depth, and verticality meet design requirements, laying a solid foundation for subsequent concrete pouring and pile formation. Furthermore, during dry drilling, only the frozen soil in the target area is cut and removed, without altering the physical and mechanical properties of the surrounding frozen soil, avoiding problems such as frozen soil thawing and strength reduction caused by mud infiltration. The removed frozen soil can also be used for backfilling the pile foundation hole, achieving resource recycling, reducing construction waste, and meeting environmental protection requirements. In desert and Gobi areas where water resources are scarce, wet drilling requires large amounts of water to prepare the mud slurry, while dry drilling requires no water, perfectly adapting to the resource situation in these areas and reducing construction costs and difficulty. In addition, rotary drilling rigs offer fast dry drilling speed and a high degree of automation. Compared with traditional manual or wet drilling, they can significantly shorten drilling time and improve construction efficiency. They are especially suitable for winter construction in permafrost areas (where temperatures are extremely low, water resources are frozen, and wet drilling is not feasible), ensuring that construction progress is not limited by the season.

[0035] II. The strength formation of concrete depends on the hydration reaction, and the rate of the hydration reaction is closely related to temperature. Excessively high or low temperatures can lead to uneven hydration, affecting the uniformity and stability of concrete strength. Temperature control ensures that concrete is maintained at a suitable initial preset temperature (e.g., 5℃-25℃, dynamically adjusted according to ambient temperature) during transportation, guaranteeing a smooth hydration reaction and preventing reduced fluidity and premature setting due to excessively low temperatures. This ensures that the concrete can be smoothly poured and densely fill the pile foundation holes after arrival at the construction site, reducing pouring defects such as honeycomb, pitting, and voids, and guaranteeing the quality of pile foundation formation. Furthermore, in winter construction scenarios with frozen soil, temperature control prevents concrete from freezing during transportation, ensuring normal hydration and guaranteeing that the concrete's strength and durability meet design requirements. In addition, the diurnal temperature range in desert and Gobi regions can reach over 20℃, and the temperature difference between winter and summer can exceed 60℃. Traditional concrete transportation methods cannot adapt to such extreme temperature changes, easily leading to fluctuations in concrete quality. This disclosure allows for dynamic adjustment of the first preset temperature based on ambient temperature, adapting to temperature changes in different seasons and time periods, ensuring stable quality during concrete transportation, and improving the adaptability and reliability of construction.

[0036] Third, in desert and Gobi regions, the large diurnal temperature range means that excessive temperature fluctuations during pouring can cause rapid changes in the concrete surface temperature while the internal temperature changes more slowly, creating a temperature difference between the inside and outside and leading to surface shrinkage cracks. By controlling the ambient temperature to maintain a stable second preset temperature, temperature fluctuations are reduced, excessive temperature differences between the inside and outside of the concrete are avoided, surface cracks are prevented, and the quality of concrete pouring is guaranteed. The hydration reaction of concrete is affected not only by its own temperature but also by the external ambient temperature. If the external ambient temperature is too low, it will inhibit the hydration reaction, resulting in slow strength growth; if the temperature is too high, it will accelerate the hydration reaction, easily leading to cracks. By controlling the ambient temperature to the second preset temperature, stable external conditions are provided for the concrete hydration reaction, ensuring its normal progress and guaranteeing normal strength growth.

[0037] Fourth, by controlling the temperature of the concrete inside the borehole and maintaining a third preset temperature (which matches the first preset temperature to ensure the continuity of concrete temperature and avoid sudden temperature changes), the internal temperature distribution of the concrete becomes uniform, reducing the temperature difference between the inside and outside and effectively inhibiting the formation of temperature cracks. Especially in permafrost areas, where the temperature inside the borehole is low, temperature control can prevent the hydration reaction from stalling due to excessively low concrete temperature, while also preventing the heat released by the hydration reaction from accumulating and causing the internal temperature to become too high, thus achieving a dynamic balance of concrete temperature. Furthermore, in winter permafrost construction scenarios, the low temperature inside the borehole slows down the concrete hydration reaction and strength gain, leading to prolonged curing time and impacting the construction cycle. By controlling the temperature of the concrete inside the borehole, the concrete temperature is increased, accelerating the hydration reaction, promoting rapid strength gain, shortening curing time, and consequently shortening the overall construction cycle and reducing construction costs.

[0038] Fifth, by continuously controlling the temperature, the concrete and its surrounding environment are maintained within a suitable temperature range, ensuring that the hydration reaction proceeds fully and steadily, allowing the concrete strength to gradually increase and ultimately meet the design requirements, satisfying the load-bearing needs of the photovoltaic pile foundation. Especially in permafrost regions, continuous temperature control prevents the concrete from freezing, ensuring the normal progress of the hydration reaction and avoiding insufficient strength. Simultaneously, after pouring, the concrete is in a shrinkage phase; temperature fluctuations exacerbate shrinkage and cause cracks. Continuous temperature control maintains temperature stability, reducing the impact of temperature fluctuations on concrete shrinkage, effectively inhibiting the formation of shrinkage and temperature cracks, improving the integrity and durability of the concrete, and extending the service life of the tower pile foundation. A stable temperature environment reduces stress concentration within the concrete, preventing crack propagation and further ensuring the quality of the pile foundation. Furthermore, continuous temperature control accelerates the concrete hydration reaction, shortens curing time, and consequently shortens the overall construction cycle. Continuous temperature control also avoids concrete quality problems caused by improper curing, reducing rework and pile replacement costs, and lowering the overall construction cost.

[0039] VI. The temperature difference between the backfill frozen soil and the target area frozen soil is controlled within a preset range (e.g., within ±2℃, which can be adjusted according to the actual frozen soil temperature). This avoids heat transfer caused by excessive temperature difference, prevents the surrounding frozen soil from melting and the backfill frozen soil from freezing, reduces the generation of temperature stress, avoids cracking and settlement of the backfill layer, ensures the stability of the backfill layer, and thus guarantees the overall stability of the pile foundation. Simultaneously, the backfill frozen soil and the surrounding frozen soil have consistent physical and mechanical properties and similar temperatures, allowing them to quickly fuse and form an integral load-bearing structure. This improves the bonding strength between the backfill layer and the surrounding frozen soil, enhances the pile foundation's pull-out and overturning resistance, and meets the requirements of the tower pile foundation to withstand various loads. The integrated backfill layer can effectively disperse the load on the pile foundation and transfer it to the surrounding frozen soil, improving the bearing efficiency of the pile foundation. In addition, once the backfilled frozen soil forms a whole with the surrounding frozen soil, it can adapt to the temperature changes in the frozen soil area, shrinking and expanding synchronously with the temperature changes. This avoids pile foundation displacement and settlement caused by the deformation difference between the backfill layer and the frozen soil, ensuring the long-term stability of the iron tower and photovoltaic power generation equipment pile foundation, and extending the service life of the iron tower and photovoltaic power generation equipment pile foundation.

[0040] In one embodiment of this disclosure, such as Figure 2 As shown, in step S200, temperature control of the concrete during transportation includes: Step S210: Concrete is transported using a hopper, and heating and insulation components are installed on the hopper to maintain the concrete in the hopper at a first preset temperature.

[0041] In desert and Gobi regions, the foundation piles for power transmission towers and photovoltaic power generation equipment are typically distributed, with each pile hole requiring a small amount of concrete. Traditional large concrete mixer trucks offer poor transportation flexibility and high costs. Bulldozers, with their moderately sized and mobile hoppers, can adjust transportation routes and volumes according to the distribution of pile holes, adapting to the needs of decentralized pile foundation construction. This avoids the inconvenience of large concrete mixer trucks in dispersed construction scenarios and improves transportation efficiency. Simultaneously, heating elements provide heat when the concrete temperature is too low, preventing freezing; insulation elements reduce heat exchange between the concrete in the hopper and the external environment, preventing rapid temperature fluctuations and ensuring the concrete remains at the preset temperature. The combined effect of heating and insulation elements effectively prevents concrete freezing, ensuring the concrete retains good fluidity upon arrival at the construction site, allowing for smooth pouring and dense filling of the pile holes, avoiding construction interruptions due to concrete freezing.

[0042] In one embodiment of this disclosure, a through hole can be provided at the bottom of the hopper, and a valve can be installed on the through hole to control the unloading. When the hopper is transporting concrete, a tarpaulin can be used to cover the concrete in the hopper to reduce the influence of external temperature on the concrete temperature. An electric heating element can be installed at the bottom outer side of the hopper to heat the hopper itself, thereby heating the concrete in the hopper.

[0043] In one embodiment of this disclosure, such as Figure 3 As shown, in step S300, during the process of pouring the pile foundation in the pile foundation hole, temperature control is performed on the environment surrounding the pile foundation hole, including: Step S310: Construct an insulated room in the target frozen soil area, and use the insulated room as an insulated room for the pouring construction area; Step S320: Install heating equipment and temperature detection equipment in the insulation room to maintain the temperature of the insulation room at the second preset temperature.

[0044] During the pouring of pile foundations in permafrost regions, the surrounding environment experiences extreme temperatures and large diurnal temperature variations, and is susceptible to severe weather conditions such as wind, sandstorms, rain, and snow. Fluctuations in ambient temperature directly affect the temperature of the concrete inside the borehole, leading to failure in concrete temperature control. This can also cause the permafrost around the pile hole to thaw, compromising the stability of the borehole wall and potentially causing collapse. Constructing an insulated enclosure effectively isolates the area from external low temperatures, preventing the impact of external temperature fluctuations on the pouring area and maintaining the temperature inside the enclosure at a pre-set second temperature. A suitable ambient temperature promotes the hydration reaction of the concrete, ensuring it proceeds fully, increasing the concrete's strength and density, and ensuring consistent concrete quality for each batch and section of the pile foundation, thus improving the overall stability of the pile foundation. The insulated enclosure can be constructed using a combination of fabric covering and steel pipe supports, offering convenient and cost-effective construction.

[0045] The heating equipment can flexibly provide heat according to the temperature inside the insulation room. When the temperature inside the insulation room is lower than the second preset lower limit, the heating equipment starts to supplement heat and quickly raise the temperature to the preset range. When the temperature reaches the preset upper limit, the heating equipment shuts off to prevent the temperature from becoming too high and to achieve dynamic temperature balance. For example, during winter construction, when the temperature inside the insulation room drops below 10℃, the heating equipment (such as electric heaters or hot air furnaces) starts to provide heat to the insulation room, allowing the temperature to quickly rise back to the second preset temperature.

[0046] Temperature detection equipment (such as temperature sensors and thermometers) can monitor the temperature inside the insulation chamber in real time and provide feedback to construction personnel. Based on this data, personnel can adjust the operation of the heating equipment to ensure the temperature remains stable within the second preset range. Furthermore, the temperature detection equipment can perform multi-point monitoring, not only monitoring the overall temperature inside the insulation chamber but also the temperature at key locations such as the pile foundation borehole and the pouring area. This ensures uniform temperature distribution and prevents localized temperature fluctuations from affecting construction quality. For example, by deploying multiple temperature sensors inside the insulation chamber to monitor the temperature at the borehole, the pouring area, and corners, if the temperature deviation at any location exceeds ±1℃, the arrangement or operating power of the heating equipment can be adjusted promptly to ensure overall temperature stability.

[0047] By combining heating and temperature detection equipment, a closed-loop temperature control system is formed, eliminating the need for continuous manual monitoring. This automates temperature control, reduces the difficulty of manual operation, and prevents temperature control failures caused by human error. For example, the temperature detection equipment monitors the temperature in real time. When the temperature falls below a preset value, it automatically triggers the heating equipment to start; when the temperature reaches the preset value, it automatically shuts down, achieving automatic temperature adjustment and ensuring continuous and stable temperature control to guarantee construction quality.

[0048] In one embodiment of this disclosure, such as Figure 4 As shown, in step S400, during the process of pouring the pile foundation in the pile foundation hole, temperature control is performed on the concrete poured into the pile foundation hole, including: Step S410: Install a heating structure inside the pile foundation hole, then pour concrete into the pile foundation hole, and use the heating structure to control the temperature of the concrete poured into the pile foundation hole.

[0049] The heating structure is directly installed inside the pile foundation hole, in direct contact with the concrete. This allows for direct heat transfer to the concrete interior, avoiding the low heat transfer efficiency of external temperature control methods. This ensures that the concrete inside the hole (including deep sections) maintains a third preset temperature, achieving uniform temperature control. Simultaneously, the heating structure dynamically adjusts the heating power and heating time based on the actual temperature of the concrete inside the hole, ensuring the concrete temperature remains consistently at the third preset temperature, preventing excessively high or low temperatures and adapting to temperature changes during the pouring process (such as exothermic hydration reactions and fluctuations in the borehole's ambient temperature). Uniform heating ensures a uniform temperature distribution within the concrete, reducing internal and external temperature differences, effectively suppressing temperature and shrinkage cracks, improving the integrity and durability of the concrete, adapting to the extreme environments of frozen soil regions, and extending the service life of photovoltaic power generation equipment pile foundations.

[0050] In one embodiment of this disclosure, the heating structure includes an electric heating element disposed in the pile foundation hole, the electric heating element being covered by concrete poured in the pile foundation hole, and the temperature of the concrete poured in the pile foundation hole being controlled by the electric heating element.

[0051] Pile foundation holes are closed or semi-closed spaces. During pouring, the concrete temperature is affected by various factors, including the ambient temperature inside the hole, the exothermic reaction of hydration, and the conduction of external ambient temperature, making temperature control extremely difficult. Electric heating elements generate heat immediately upon connection to the power supply, eliminating the need for preheating. They can quickly transfer heat to the concrete, rapidly raising its temperature to a preset level (e.g., 5℃~15℃, suitable for winter construction in frozen soil regions). In extreme winter temperatures in frozen soil regions (ambient temperatures can reach below -20℃, and the temperature inside the hole is even lower), if the concrete cannot be rapidly heated after pouring, it will freeze quickly, halting the hydration reaction. This prevents the concrete from reaching its design strength, rendering it a waste pile, resulting in wasted construction costs and project delays. The rapid response of electric heating elements effectively avoids this problem, ensuring the concrete is quickly maintained at a suitable temperature after pouring, guaranteeing the normal initiation of the hydration reaction and laying a solid foundation for concrete strength growth. Furthermore, the hydration reaction of concrete is extremely sensitive to temperature. Excessive temperature fluctuations (above ±2℃) can lead to uneven hydration, resulting in temperature cracks and affecting the concrete's strength and durability. The electric heating element can precisely control the heat generation by adjusting parameters such as the power supply voltage and current, thereby achieving precise temperature control of the concrete. This ensures that the concrete temperature remains stable within a third preset temperature range, with an error controlled within ±1℃, far exceeding the temperature control accuracy of traditional heating methods. For example, when the concrete temperature inside the hole rises to the upper limit of the third preset temperature due to the exothermic hydration reaction, the power supply current can be reduced by the current controller to decrease the heat generation of the electric heating element. Conversely, when the temperature inside the hole drops to the lower limit of the preset temperature due to external low-temperature conduction, the current can be increased to enhance the heat generation, achieving dynamic temperature balance and effectively suppressing the formation of temperature cracks. This precise temperature control capability ensures uniform temperature distribution within the concrete, avoiding excessively high or low temperatures in certain areas, and guaranteeing the uniformity and stability of the concrete strength.

[0052] In one embodiment of this disclosure, the heating structure includes a cylindrical heating element, in which concrete is poured to form a concrete pile foundation; the cylindrical heating element is provided with an electric heating element, which controls the temperature of the concrete poured in the pile foundation hole.

[0053] Cylindrical heating elements can be directly inserted into the pile foundation borehole, fitting snugly against the borehole wall. They effectively support and protect the borehole wall, dispersing stress and preventing collapse, thus providing a stable and safe construction environment for concrete pouring. For example, cylindrical heating elements made of high-strength steel have strong load-bearing capacity, capable of withstanding the pressure of the soil around the borehole wall and preventing collapse due to disturbance or temperature changes. This is particularly suitable for frozen soil areas with poor borehole wall stability. Simultaneously, as a pouring template, the cylindrical heating element guides the uniform filling of concrete, preventing segregation and flow during pouring, ensuring a dense and well-formed concrete pour.

[0054] The cylindrical heating element creates a closed heating space, concentrating heat and reducing heat conduction to the borehole walls and deeper underground layers, thus minimizing heat loss and improving temperature control efficiency. Simultaneously, the cylindrical heating element is integrally arranged along the depth of the pile foundation borehole, with electric heating elements evenly distributed within the cylindrical structure. Heat is uniformly transferred to the concrete throughout the entire depth via the cylindrical structure, effectively eliminating temperature differences between the top and bottom layers and ensuring that the concrete temperature at different depths remains consistently at the third preset temperature, guaranteeing uniform overall strength of the pile foundation. Furthermore, the cylindrical heating element can be flexibly customized according to the depth and diameter of the pile foundation borehole, adapting to both shallow and deep pile foundations, as well as small and large diameter pile foundations.

[0055] In one embodiment of this disclosure, the electric heating element includes a reinforcing bar, and the heating structure further includes a current controller. The current controller is connected to the reinforcing bar and controls the heat generation of the reinforcing bar through the current controller.

[0056] Reinforcing steel bars are the core reinforcing material for pile foundation concrete, enhancing the tensile and compressive strength and toughness of the concrete, and improving the bearing capacity and deformation resistance of the pile foundation. Using them as electric heating elements eliminates the need for separately purchasing specialized equipment such as heating wires and heating plates, saving on the cost of electric heating equipment. This is particularly suitable for large-scale pile foundation construction, significantly reducing the overall construction cost. The arrangement of reinforcing steel bars simultaneously meets the needs of structural reinforcement and temperature control, simplifying the construction process, reducing construction steps, and improving construction efficiency. After construction, the reinforcing steel bars remain an integral part of the pile foundation, forming a unified whole with the concrete, generating no construction waste. This achieves full utilization of materials, meets environmental protection construction requirements, and aligns with the core requirements of clean and environmentally friendly photovoltaic power generation.

[0057] The reinforcing bars are evenly distributed within the pile foundation hole (e.g., evenly arranged along the circumference and depth of the hole). As an electric heating element, they can evenly transfer heat to the surrounding concrete, preventing localized overheating or underheating and achieving uniform temperature control of the concrete. The large heat transfer area and uniform heat transfer of the reinforcing bars ensure that the concrete temperature of the entire pile foundation is maintained at a preset third temperature, with temperature deviation controllable within ±0.5℃, further improving temperature control accuracy. A current controller is connected to the reinforcing bars, allowing precise control of the heat generated by the reinforcing bars by adjusting parameters such as current magnitude and energizing time, achieving dynamic temperature control.

[0058] In one embodiment of this disclosure, such as Figure 5 As shown, in step S600, after the concrete pouring in the pile foundation hole is completed, the pile foundation hole is backfilled with frozen soil whose temperature difference with the target frozen soil area is within a preset temperature range, including: Step S610: When forming pile foundation holes in the target frozen soil area, temperature control is performed on the frozen soil excavated to form the pile foundation holes so that the temperature difference between the excavated frozen soil and the frozen soil in the target frozen soil area is within a preset temperature range. Step S620: After the concrete in the pile foundation hole is poured, the excavated frozen soil is used for backfilling.

[0059] Once excavated from the ground, the frozen soil is immediately exposed to the external environment, causing rapid temperature changes. By simultaneously controlling the temperature of the excavated frozen soil during the drilling process, its temperature can be stabilized in a timely manner, preventing significant temperature increases or decreases due to ambient temperature fluctuations. This ensures that the temperature of the backfill frozen soil consistently meets requirements, with the temperature difference between the backfill and the target frozen soil area controlled within a preset range (e.g., ±3℃). Precisely controlling the temperature difference between the backfill and the target frozen soil area effectively reduces temperature stress, preventing cracking and settlement of the backfill layer. It also ensures rapid fusion of the backfill frozen soil with the surrounding frozen soil, forming a unified load-bearing structure, improving the bonding strength and stability of the backfill layer, and thus enhancing the pile foundation's pull-out and overturning resistance. Furthermore, the excavated frozen soil is directly piled around the pile foundation hole and can be used directly for backfilling after pouring, eliminating the need for long-distance transportation. This reduces the investment in transportation vehicles and energy consumption during transportation, lowering transportation costs. It also avoids temperature changes in the frozen soil during long-distance transportation (such as thawing upon heating and freezing upon cooling), ensuring that the temperature of the backfill frozen soil meets requirements. Meanwhile, the air-cooling equipment can precisely control the airflow speed by adjusting parameters such as fan speed and air outlet direction, thereby precisely controlling the temperature change of the frozen soil. This ensures that the temperature difference between the excavated frozen soil and the target frozen soil area is controlled within a preset range, avoiding excessive temperature fluctuations and guaranteeing the quality of the backfilled frozen soil.

[0060] In one embodiment of this disclosure, the excavated frozen soil is temperature-controlled using air-cooling equipment. For example, a fan is used to cool the excavated frozen soil using cool air from the environment, ensuring that the temperature difference between the excavated frozen soil and the target frozen soil area is within a preset temperature range. Desert and Gobi regions are rich in wind resources; air-cooling equipment can utilize natural wind to accelerate airflow, improve heat exchange efficiency, reduce temperature control energy consumption, and simultaneously speed up temperature control, ensuring that the excavated frozen soil quickly reaches the preset temperature to meet construction schedule requirements.

[0061] It is understandable that electric cooling devices can also be used to control the temperature of the excavated frozen soil, for example, by inserting a semiconductor cooling rod into the frozen soil and then energizing the rod to control its temperature.

[0062] In one embodiment of this disclosure, such as Figure 6 As shown, in step S600, after the concrete pouring in the pile foundation hole is completed, the pile foundation hole is backfilled with frozen soil whose temperature difference with the target frozen soil area is within a preset temperature range, including: Step S630: Excavate frozen soil around the pile foundation hole in the target frozen soil area. After the concrete in the pile foundation hole is poured, use the frozen soil excavated around the pile foundation hole to backfill the pile foundation hole.

[0063] The temperature of the surrounding frozen soil is completely identical to that of the target frozen soil area, with an almost zero temperature difference. This eliminates the need for additional temperature control measures, reducing construction difficulty and costs. It also completely avoids heat transfer and temperature stress caused by temperature differences, effectively preventing cracking and settlement of the backfill layer and ensuring its stability. Furthermore, the surrounding frozen soil is identical to the frozen soil around the pile foundation holes in terms of particle composition, density, and frost resistance. After backfilling, it fuses rapidly to form a unified load-bearing structure with a bonding strength far exceeding that achieved using external frozen soil or other backfill materials. This further enhances the pile foundation's pull-out and overturning resistance, ensuring its long-term stability. In addition, the surrounding frozen soil contracts and expands synchronously with the surrounding soil, avoiding deformation differences between the backfill layer and the surrounding soil. This prevents pile foundation displacement and settlement, ensuring the long-term stable operation of the tower and photovoltaic power generation equipment pile foundations, and allowing them to adapt to extreme temperature changes in the frozen soil region.

[0064] It should be noted that this disclosure does not limit the specific values ​​of the first preset temperature, the second preset temperature, the third preset temperature, and the preset temperature range of the temperature difference, and these values ​​can be set according to the specific conditions of the construction site. Each of the above parameters can be a single value or a range of values, and this disclosure does not limit this.

[0065] Furthermore, although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0066] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A construction method for iron tower pile foundations in permafrost regions, characterized in that, include: Select a target frozen soil area, and use rotary drilling rig dry drilling technology to form pile foundation holes in the target frozen soil area; Temperature control is implemented during concrete transportation to maintain the concrete at a first preset temperature. During the process of pouring the pile foundation in the pile foundation hole, the temperature of the environment around the pile foundation hole is controlled so that the environment around the pile foundation hole is maintained at a second preset temperature. During the process of pouring the pile foundation in the pile foundation hole, the concrete poured in the pile foundation hole is temperature controlled so that the concrete poured in the pile foundation hole is maintained at a third preset temperature. After the concrete in the pile foundation hole is poured, the temperature of the concrete in the pile foundation hole and the surrounding environment is controlled for a preset time. After the concrete in the pile foundation hole is poured, the pile foundation hole is backfilled with frozen soil whose temperature difference with the frozen soil in the target frozen soil area is within a preset temperature range.

2. The construction method according to claim 1, characterized in that, After the concrete pouring in the pile foundation hole is completed, the pile foundation hole is backfilled with frozen soil whose temperature difference with the target frozen soil area is within a preset temperature range, including: When the pile foundation hole is formed in the target frozen soil area, the frozen soil excavated to form the pile foundation hole is temperature controlled so that the temperature difference between the excavated frozen soil and the frozen soil in the target frozen soil area is within a preset temperature range. After the concrete in the pile foundation hole is poured, the excavated frozen soil is used for backfilling.

3. The construction method according to claim 2, characterized in that, The temperature of the excavated frozen soil is controlled using air-cooling equipment.

4. The construction method according to claim 1, characterized in that, After the concrete pouring in the pile foundation hole is completed, the pile foundation hole is backfilled with frozen soil whose temperature difference with the target frozen soil area is within a preset temperature range, including: Frozen soil is excavated around the pile foundation hole in the target frozen soil area. After the concrete in the pile foundation hole is poured, the frozen soil excavated around the pile foundation hole is used to backfill the pile foundation hole.

5. The construction method according to claim 1, characterized in that, During the process of pouring the pile foundation in the pile foundation hole, temperature control is performed on the concrete poured into the pile foundation hole, including: A heating structure is installed inside the pile foundation hole, and then concrete is poured into the pile foundation hole. The temperature of the concrete poured into the pile foundation hole is controlled by the heating structure.

6. The construction method according to claim 5, characterized in that, The heating structure includes an electric heating element disposed in the pile foundation hole. The concrete poured in the pile foundation hole covers the electric heating element, and the electric heating element controls the temperature of the concrete poured in the pile foundation hole.

7. The construction method according to claim 5, characterized in that, The heating structure includes a cylindrical heating element, and concrete is poured into the cylindrical heating element to form a concrete pile foundation; The cylindrical heating element is equipped with an electric heating element, which controls the temperature of the concrete poured into the pile foundation hole.

8. The construction method according to claim 6 or 7, characterized in that, The electric heating element includes a steel bar, and the heating structure also includes a current controller. The current controller is connected to the steel bar and controls the heat generation of the steel bar.

9. The construction method according to claim 1, characterized in that, Temperature control of concrete during transportation includes: Concrete is transported using a hopper, and heating and insulation components are installed on the hopper to maintain the concrete in the hopper at the first preset temperature.

10. The construction method according to claim 1, characterized in that, During the process of pouring the pile foundation in the pile foundation hole, temperature control is performed on the environment surrounding the pile foundation hole, including: Insulated rooms are built in the target permafrost area, and these insulated rooms serve as insulation rooms for the pouring construction area. Heating equipment and temperature detection equipment are installed in the insulation room to maintain the temperature of the insulation room at a second preset temperature.

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