Temperature-controlled pile-supported embankment structure with tie beam and construction method thereof

Abstract

The application provides a temperature control type pile-bearing embankment structure with tie beams and a construction method thereof, which comprises, from bottom to top, a threaded pile layer, a connecting layer, a cushion layer, a geogrid layer and an embankment layer; the threaded pile layer comprises a plurality of vertical threaded piles, and each threaded pile comprises a pile body, a pile cap, a pile tip and a heat exchange channel arranged in the pile body; the connecting layer comprises a grid structure formed by tie beams connecting adjacent pile caps and has a built-in grouting pipe network; the application further comprises an energy supply module, an active temperature control module and a monitoring and control module. The threaded pile body cavity and the refrigeration assembly form a closed loop circulation system through the heat exchange pipe, and the coolant flows through the heat exchange pipe to absorb the heat of the soil around the pile under the driving of the compressor; in cooperation with the temperature sensor and the threshold control of the microcontroller, the refrigeration assembly can be automatically started and stopped, the frozen soil temperature can be effectively maintained stable, and the frost-heave settlement can be inhibited.

Description

Technical Field

[0001] This invention belongs to the field of frozen soil road engineering technology, specifically a temperature-controlled pile-supported embankment structure with tie beams and its construction method. Background Technology

[0002] In road construction in permafrost regions, foundation treatment technologies face stability challenges due to temperature sensitivity, freeze-thaw cycles, and long-term loads. Pile-supported embankments, as an efficient foundation reinforcement method, transfer the embankment load to deep, stable soil layers through pile foundations, significantly reducing the risk of foundation settlement. Meanwhile, temperature control technology is becoming increasingly common in permafrost engineering, regulating foundation temperature through heat pipes, insulation materials, or ventilation systems to suppress the destructive effects of freeze-thaw cycles on soil mechanical properties. The combination of these two technologies forms temperature-controlled pile-supported embankment technology, considered an important development direction for improving the durability of embankments in permafrost regions.

[0003] However, with the increasing frequency of extreme weather events and the long-term effects of traffic loads, existing technologies have gradually revealed the following key technical shortcomings in practical engineering:

[0004] 1. Existing pile-supported embankment structures lack active temperature regulation capabilities and a heat exchange mechanism with permafrost, making it impossible to actively maintain the low temperature state of the permafrost near the pile foundation. This leads to a decrease in the pull-out resistance at the pile-soil interface and a decline in the bearing capacity of the pile foundation over time. At the same time, under the background of climate warming, the temperature of the permafrost around the piles rises, resulting in a decrease in the shear strength of the soil and accelerating the creep settlement of the pile foundation. This problem is particularly prominent in high-temperature permafrost areas and directly affects the long-term service performance of the embankment structure.

[0005] 2. Under long-term cyclic traffic loads, the soil arch structure between piles is prone to progressive failure, leading to a decrease in soil pressure at the pile top and uneven cumulative settlement of the embankment. Traditional pile-supported embankments typically employ passive repair methods such as ground grouting or pile-side reinforcement after settlement occurs. However, these methods rely on visual inspection or manual monitoring data, resulting in problems such as delayed response and blind reinforcement scope. Furthermore, they cannot be repaired promptly and effectively when problems arise, further exacerbating the damage to the pile-supported embankment.

[0006] 3. Existing temperature control technologies often rely on external power grids or diesel generators to maintain the operation of refrigeration equipment, which faces challenges such as poor power supply stability and high maintenance costs in remote areas like polar regions and high-altitude frigid zones. While temperature control solutions using structures such as steel pipe threaded piles can reduce energy consumption, they cannot achieve real-time monitoring and dynamic adjustment of permafrost temperatures. Furthermore, the lack of an integrated monitoring and control system means that equipment start-up and shutdown depend on manual intervention, making it unable to respond to transient fluctuations in permafrost temperatures, thus exacerbating energy waste and temperature control lag.

[0007] In summary, existing temperature-controlled pile-supported embankment technology has systemic shortcomings in areas such as active temperature control of frozen soil, pile-soil synergistic bearing capacity, energy self-sufficiency, and intelligent reinforcement. These problems severely restrict the large-scale application of temperature-controlled pile-supported embankments in high-altitude and cold regions, and technological breakthroughs are urgently needed through innovation. Summary of the Invention

[0008] The main objective of this invention is to provide a temperature-controlled pile-bearing embankment structure with tie beams that can actively adjust the temperature of the frozen soil around the pile foundation, and its construction method.

[0009] The present invention provides a temperature-controlled pile-supported embankment structure with tie beams, comprising, from bottom to top, a threaded pile layer, a connecting layer, a cushion layer, a geogrid layer, and an embankment layer; the threaded pile layer includes multiple vertical threaded piles, each including a pile body, a pile cap, a pile tip, and a heat exchange channel inside the pile body; the connecting layer includes a grid structure formed by tie beams connecting adjacent pile caps, with an internal grouting network; it also includes an energy supply module, an active temperature control module, and a monitoring and control module; the energy supply module includes a power generation unit and an energy storage unit to supply power to each module; the active temperature control module includes a coolant circulation system connected to the heat exchange channels; the monitoring and control module includes an earth pressure sensor array, a temperature sensor array, and a control unit connected to the sensors; the control unit regulates the operation of the active temperature control module based on temperature sensor data and performs grouting reinforcement based on earth pressure sensor data.

[0010] In one embodiment of the above structure, the connecting layer includes a connecting cap, a tie beam, a main grouting pipe, and branch grouting pipes; both the connecting cap and the tie beam are made of reinforced concrete; the connecting cap is square and wraps around and fixes each pile cap; the tie beam connects adjacent connecting caps; each tie beam has a main grouting pipe embedded along its length; the inlet end of the grouting pipe extends to the outside of the embankment slope; multiple branch grouting pipes are evenly arranged on the main grouting pipe in the tie beam.

[0011] In one embodiment of the above structure, the cushion layer includes a fine sand layer and a crushed stone cushion layer; the fine sand layer is laid on the upper surface of the connecting layer; the crushed stone cushion layer is laid on the fine sand layer, wherein a soil pressure sensor is embedded; the soil pressure sensor is correspondingly set at the upper center and four corners of the connecting cap.

[0012] In one embodiment of the above structure, the energy supply module includes a solar panel, a charging controller, and a battery pack connected in series; the solar panel is placed on the ground and is a monocrystalline silicon solar panel; the charging controller is a PWM type charging controller in solar charging controllers; and the battery pack is an iron carbonate battery pack.

[0013] In one embodiment of the above structure, the active temperature control module includes a refrigeration circuit consisting of a compressor, a condenser, and a throttling device; the outlet of the throttling device and the inlet of the compressor are respectively connected to a heat exchange tube.

[0014] In one embodiment of the above structure, the temperature sensor array includes temperature sensors buried in the frozen soil around each threaded pile, each temperature sensor is connected to a microcontroller, and the microcontroller is connected to a compressor.

[0015] In one embodiment of the above structure, the threaded pile body is a hollow cylinder, with a smooth upper section and a threaded lower section. The top is connected to the pile cap, and the bottom is connected to the pile tip. The pile cap is a cylindrical structure with openings on both sides through which heat exchange pipes pass and liquid inlet holes are provided. The pile tip is a conical structure. A heat exchange pipe is installed inside the hollow cavity of the threaded pile body. The heat exchange pipe is a copper pipe, and coolant flows through the pipe. The liquid inlet pipe of the heat exchange pipe passes through the hole on the pile cap, extends through the pile top interface to the pile bottom interface, and then vertically upwards through the hole on the other side of the pile cap. The remaining space of the hollow cavity of the steel pipe threaded pile body is filled with coolant.

[0016] In one embodiment of the above structure, the pile body is a hollow cylinder with a diameter that gradually decreases from top to bottom, with the pile cap connected to the top and the pile tip connected to the bottom; the pile cap is a cylindrical structure with inlet and outlet holes on both sides; the pile tip is a conical structure; the pile body is also provided with spiral threads that are fixed around the pile body, and the cross-section of the threads is a hollow triangle; a heat exchange pipe is embedded in the cavity of the threads; the heat exchange pipe is a copper pipe covered with an insulation layer; the water inlet pipe of the heat exchange pipe passes through the inlet hole, extends through the pile top interface to the pile bottom interface, and then extends vertically upward through the outlet hole.

[0017] A method for constructing the above-mentioned structure, comprising the following specific steps:

[0018] S1. Geological exploration and layout of threaded pile points

[0019] Conduct site geological surveys, and determine the vertical placement points of the threaded piles based on the survey results and design loads; the spacing of the threaded piles is arranged in a grid pattern with a fixed center distance.

[0020] S2. Threaded pile driving construction

[0021] A static pressure boosting type rotary pile machine is used to vertically screw the threaded pile into the foundation, and the verticality deviation is monitored in real time during the screwing process; the top of the pile is above the ground, and the liquid inlet and outlet holes on both sides of the pile cap are exposed.

[0022] S3, Temperature Sensing Component Installation

[0023] First, temperature sensors are buried in the soil around the threaded piles, and measuring points are arranged at fixed intervals along the depth direction; then, the signal lines of the temperature sensors are led to the side of the connecting layer and connected to the microcontroller; finally, the sensor sensitivity is calibrated and the temperature threshold is set.

[0024] S4, Installation of power generation and cooling components

[0025] Connect the heat exchanger inlet pipe to the throttle outlet through the pile cap hole, and connect the outlet pipe to the compressor inlet through the other hole; inject coolant into the pile cavity through the pile cap inlet hole and seal it; check for leaks to ensure the sealing of the circulation pipeline and the pile cavity; fix the solar panel to the sunny side of the embankment and connect it to the battery pack through the charging controller; finally, complete the electrical connection between the compressor and the microcontroller.

[0026] S5, Construction of connecting layer pouring

[0027] Erect connecting caps and tie beam formwork at the top of the threaded piles, and tie the reinforcing cage; pre-embed the main and branch grouting pipes, with the main pipe inlet extending to the outside of the embankment slope; pour concrete, vibrate it to compact it, cover and cure it, and remove the formwork after the strength reaches the design requirements.

[0028] S6. Layered filling construction

[0029] A fine sand leveling layer is laid on the surface of the connecting layer, which is then manually leveled and mechanically compacted; a graded crushed stone cushion layer is laid, and earth pressure sensors are buried with a fixed spacing grid arrangement; a two-way plastic geogrid layer is laid, and U-shaped nails are used to anchor the joints; the embankment fill is filled in 5 layers, and the next layer can only be constructed after the compaction degree of each layer has been tested and qualified.

[0030] S7, System Integration and Verification

[0031] A comprehensive inspection was conducted on the helical pile, refrigeration components, power generation components, and temperature sensing components; the refrigeration components were started, and the circulation of coolant in the heat exchange tubes was observed; temperature sensor readings were monitored; temperature threshold triggering conditions were simulated to verify that the microcontroller could automatically start the compressor when the temperature was lower than the set temperature threshold; and finally, a pre-run verification was performed.

[0032] S8, Subsequent dynamic grouting reinforcement

[0033] The soil pressure sensor continuously monitors the pressure data, and the embankment structure is reinforced by grouting in stages based on the pressure data.

[0034] A method for dynamically grouting and reinforcing the above-mentioned embankment structure includes the following specific steps:

[0035] A pressure-time curve is generated based on continuously monitored pressure data, and a curvature threshold is preset; the curvature of the pressure-time curve is calculated using the following formula:

[0036]

[0037] In the formula: k is the curvature of the pressure-time curve; P i+1 P represents the grouting pressure at time i+1; i P represents the grouting pressure at time i; i-1 Let P be the grouting pressure at time i-1; max(P) is the maximum pressure value that occurs during the grouting process.

[0038] The threshold was determined by experimental calibration. Multiple grouting tests were conducted in the test section, and the complete pressure-time curve was recorded. The moment when obvious grout return or pressure surge occurred was determined, the corresponding curvature was calculated, and the results of multiple grouting tests were statistically analyzed to obtain the empirical curvature threshold.

[0039] When the curvature of the pressure-time curve is less than the curvature threshold, a reinforcement indicator point is identified, and grouting reinforcement is initiated by injecting grout through the main and branch pipes. The curvature change of the curve is monitored in real time. When the curvature of the pressure-time curve is greater than or equal to the curvature threshold, the grouting reinforcement operation ends. When the curvature of the pressure-time curve is less than the curvature threshold again, the next round of grouting reinforcement operation is started. The monitoring-grouting process is repeated until the curvature of the curve is stably greater than or equal to the curvature threshold, confirming that the reinforcement is complete.

[0040] The beneficial effects of this invention are as follows:

[0041] 1. Through the closed-loop circulation system of heat exchange pipes and refrigeration components inside the threaded pile body, the coolant flows through the heat exchange pipes under the drive of the compressor to absorb heat from the soil around the pile. With the real-time monitoring of temperature sensors and threshold control of microcontrollers, the refrigeration components can be automatically started and stopped, effectively maintaining the stability of frozen soil temperature and inhibiting freeze-thaw settlement.

[0042] 2. A grid-like rigid structure is formed by connecting adjacent pile caps with reinforced concrete tie beams, and a network of main and branch grouting pipes is pre-embedded. Based on the monitoring data of the soil pressure sensor, grouting reinforcement is triggered by determining the curvature threshold of the pressure-time curve, so as to realize the adaptive reinforcement of the pile foundation system and enhance the stability of the embankment under cyclic load.

[0043] 3. The power generation component, consisting of solar panels and battery packs, continuously supplies power to the cooling component. Combined with the linkage control of temperature sensors and microcontrollers, a closed loop of all-weather temperature monitoring and cooling regulation is formed to ensure the autonomous operation of the device in the polar environment. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the front structure of an embankment according to an embodiment of the present invention.

[0045] Figure 2 This is a schematic diagram of the threaded pile in Example 1.

[0046] Figure 3 for Figure 2 A schematic diagram of the cross-sectional structure.

[0047] Figure 4 for Figure 1 A schematic diagram of the intermediate connecting layer.

[0048] Figure 5 This is a schematic diagram of the arrangement structure of the earth pressure sensor.

[0049] Figure 6 This is a flowchart of the construction method for embankment structures.

[0050] Figure 7 This is a schematic diagram of the front structure of an embankment structure according to another embodiment.

[0051] Figure 8 for Figure 7 A schematic diagram of the structure of a spiral pile.

[0052] Figure 9 for Figure 8 A schematic diagram of the cross-sectional structure.

[0053] Figure 10 for Figure 9 A schematic diagram of the structure of the heat exchange tube.

[0054] The attached figures are labeled as follows:

[0055] 1. Threaded pile layer; 11. Pile body; 12. Pile cap; 13. Pile tip drill bit; 14. Thread; 15. Heat exchange pipe; 16. Liquid inlet hole; 17. Pile body cavity; 2. Connecting layer; 21. Connecting cap; 22. Tie beam; 23. Main grouting pipe; 24. Branch grouting pipe; 3. Subbase; 31. Earth pressure sensor; 4. Geogrid layer; 5. Embankment layer. Detailed Implementation

[0056] The relevant technical solutions will now be clearly and completely described with reference to the accompanying drawings of the embodiments of the present invention. The described embodiments are only a part of the embodiments, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] Example 1, such as Figure 1 As shown, the temperature-controlled pile-supported embankment structure with tie beams disclosed in this embodiment includes, from bottom to top, a helical pile layer 1, a connecting layer 2, a cushion layer 3, a geogrid layer 4, and an embankment layer 5.

[0058] The threaded pile layer 1 is used to support the overall structure of this embankment. The threaded pile layer includes several steel pipe threaded piles that are set vertically relative to the ground.

[0059] like Figure 2 As shown, the steel pipe threaded pile is made of high-strength steel and includes a pile body 11, a pile cap 12, a pile tip 13, threads 14, and a heat exchange pipe 15.

[0060] The pile body 11 is a hollow cylinder with a smooth upper section and a threaded lower section. The top is connected to the pile cap 12, and the bottom is connected to the pile tip 13. The internal cavity of the pile body 11 is the pile body cavity 17, which is used to contain the coolant and the heat exchange pipe 15 to achieve uniform heat exchange throughout the entire pile body.

[0061] The pile cap 12 is a cylindrical structure with heat exchange pipe inlet and outlet holes and pile body cavity liquid inlet holes on both sides. It also has a separate liquid inlet hole 16 for the pile body cavity to inject coolant into the pile body cavity 17. After injection, it is sealed.

[0062] The pile tip 13 is a tapered drill bit, which is easy to screw into the frozen soil layer. The thread 14 is threaded around the pile body 11 and welded in place; the cross-section of the thread is triangular.

[0063] like Figure 3 As shown, the heat exchange pipe 15 is built into the cavity of the pile body. The heat exchange pipe is a copper pipe. The liquid inlet pipe of the heat exchange pipe passes through the hole on the pile cap, extends through the pile top interface to the pile bottom interface, and then extends vertically upward through the hole on the other side of the pile cap to form a closed loop.

[0064] The helical pile in this embodiment is made of Q235B steel, with a pile length of 4m, an outer diameter of 220mm, a wall thickness of 10mm, a thread bottom thickness of 5mm, a thread width of 25mm, a thread spacing of 100mm, a thread inclination angle of 80°, a thread distribution length of 2.7m (approximately 2 / 3 of the pile length), and a cone end length of 800mm. The ratio of the pile modulus to the soil modulus is greater than 75, allowing for factory prefabrication of steel piles followed by on-site welding. The pile is then connected to the connecting layer 2 by on-site concrete pouring.

[0065] like Figure 4 As shown, the connecting layer 2 includes a connecting cap 21, a tie beam 22, a main grouting pipe 23, and a branch grouting pipe 24.

[0066] Both the connecting cap 21 and the tie beam 22 are made of reinforced concrete; the connecting cap is square and wraps around and fixes each pile cap; the tie beam connects adjacent connecting caps.

[0067] Each tie beam 22 is equipped with a main grouting pipe 23 along its length, and the connection node of each main pipe is located in the connection cap; after the tie beam is poured, the outlet of the branch grouting pipe is exposed outside the tie beam template, while the inlet of the main grouting pipe is reserved on the outside of the embankment.

[0068] In this embodiment, the connecting cap has a side length of 1m and a thickness of 0.25m, and the center-to-center distance between each pile cap is 2.5m; the tie beam is 1.5m long, and the cross-section of the tie beam is a rectangle with a length of 0.5m and a width of 0.25m; both the main grouting pipe and the branch grouting pipe are made of PU material, the outer diameter of the main grouting pipe is 100mm, and the outer diameter of the branch grouting pipe is 25mm; a branch grouting pipe is arranged every 0.5m along the length of the tie beam.

[0069] The subbase 3 includes a fine sand layer and a crushed stone layer. The fine sand layer is laid on the upper surface of the connecting layer 2 and serves to level and diffuse pressure. Figure 5 As shown, a crushed stone cushion layer is laid on a fine sand layer, with 31 soil pressure sensors embedded within it. The soil pressure sensors are positioned at the upper center and four corners of the connecting cap. The thickness of the crushed stone cushion layer is no more than 250 mm, and in this embodiment, it is preferably 100 mm.

[0070] The geogrid layer 4 includes a bidirectional plastic geogrid laid on top of the crushed stone cushion layer. In this embodiment, the long-term tensile stiffness of the geogrid layer is greater than 5000 kN / m.

[0071] The embankment is divided into 5 layers and each layer is compacted, with each layer being 0.5m thick.

[0072] The embankment structure also includes power generation components, cooling components, and temperature sensing components.

[0073] The power generation assembly includes solar panels, a charge controller, and a battery pack connected in series.

[0074] The solar panels are placed on the ground and use monocrystalline silicon solar cells. The conversion efficiency of the photovoltaic modules generally reaches more than 20%, which is the mainstream product for commercial and industrial production. The charging controller adopts the PWM type charging controller in solar charging controllers to optimize charging and discharging efficiency. The battery pack adopts the commonly used iron carbonate battery pack on the market to ensure continuous power supply in polar environments.

[0075] The refrigeration assembly includes a compressor, a condenser, and a throttle connected in series, with the outlet of the throttle connected to the heat exchange tube 15.

[0076] In this refrigeration system, the liquid coolant is pressurized by the compressor and then liquefied in the condenser. It flows through the throttle into the heat exchange tube 15 of the helical pile 1, and then returns to the compressor to complete the cycle. This cools the coolant in the pile cavity, thereby absorbing heat from the soil around the pile, reducing the temperature of the frozen soil, and preventing thermal thawing settlement.

[0077] The compressor in this embodiment is a screw compressor, which has a simple structure, few vulnerable parts, low exhaust temperature, and high pressure ratio; the coolant used is ethylene glycol coolant.

[0078] The temperature sensing component includes an interconnected microcontroller and a temperature sensor. The temperature sensor is buried in the frozen soil around the pile, and the microcontroller is connected to the compressor to regulate the compressor's operating status.

[0079] When the soil temperature around the pile exceeds a set threshold, the microcontroller starts the compressor, driving the circulation of ethylene glycol coolant to lower the soil temperature. Once the temperature stabilizes below the set value, the compressor stops working, achieving temperature control. The component supports multiple start-stop cycles to ensure long-term stability of the frozen soil.

[0080] The microcontroller in this embodiment uses the Microchip PIC series, and the temperature sensor uses a commonly available thermocouple temperature sensor.

[0081] The battery pack of the power generation component is connected to the compressor and microcontroller to supply power.

[0082] It should be noted that the present invention is not limited to the above embodiments, and the heat exchange tube material, refrigerant type and power generation component configuration can be adjusted according to actual engineering needs.

[0083] like Figure 6 As shown, the specific steps for constructing and installing this embankment structure are as follows:

[0084] S1. Geological exploration and layout of threaded pile points

[0085] Conduct a site geological survey to clarify the distribution of soil and permafrost. Based on the survey results and design load, determine the vertical placement points of the steel pipe threaded piles to ensure effective reduction of permafrost temperature; the spacing of the helical piles is arranged in a grid pattern with fixed center distances.

[0086] S2. Threaded pile driving construction

[0087] A static pressure boosting type rotary pile machine is used to vertically screw the threaded pile into the foundation. The verticality deviation is monitored in real time during the screwing process to ensure that the pile body is not tilted or loose. The top of the pile is above the ground and the pile cap hole is exposed.

[0088] S3, Temperature Sensing Component Installation

[0089] First, temperature sensors are buried in the soil around the threaded pile, and measuring points are arranged at fixed intervals along the depth direction to ensure accurate monitoring of the surrounding soil temperature; then, the signal lines of the temperature sensors are led to the side of the connecting layer and connected to the microcontroller; finally, the sensor sensitivity is calibrated and the temperature threshold is set.

[0090] S4, Installation of power generation and cooling components

[0091] Connect the heat exchanger inlet pipe to the throttle outlet through the pile cap hole, and connect the outlet pipe to the compressor inlet through the other hole; inject coolant into the pile cavity through the pile cap inlet hole and seal it; check for leaks to ensure the sealing of the circulation pipeline and the pile cavity; fix the solar panel at a 20° tilt angle on the sunny side of the embankment and connect it to the battery pack through the charging controller; finally, complete the electrical connection between the compressor and the microcontroller.

[0092] S5, Construction of connecting layer pouring

[0093] Erect connecting caps and tie beam formwork at the top of the piles, and tie the reinforcing cage; pre-embed the main and branch grouting pipes, with the main pipe inlet extending to the outside of the embankment slope; pour concrete, vibrate it to compact it, cover and cure it, and remove the formwork after the strength reaches the design requirements.

[0094] S6. Layered filling construction

[0095] A fine sand leveling layer is laid on the surface of the connecting layer, which is then manually leveled and mechanically compacted; a graded crushed stone cushion layer is laid, and soil pressure sensors are installed with a fixed spacing grid; a two-way plastic geogrid layer is laid, and U-shaped nails are used to anchor the joints; the embankment fill is constructed in 5 layers, and the next layer can only be constructed after the compaction degree of each layer has been tested and qualified.

[0096] S7, System Integration and Verification

[0097] A comprehensive inspection was conducted on the threaded piles, cooling components, power generation components, and temperature sensing components to ensure that all components were installed correctly. The cooling components were started, and the circulation of coolant in the heat exchange pipes was observed to ensure good heat exchange performance. Temperature sensor readings were monitored to ensure that they could accurately reflect changes in soil temperature around the threaded piles. Temperature threshold triggering conditions were simulated to verify that the microcontroller could automatically start the compressor when the temperature was lower than the set temperature threshold. Finally, the system was run continuously for 48 hours to ensure that the soil temperature around the threaded piles remained within the expected temperature range.

[0098] S8, Subsequent dynamic grouting reinforcement

[0099] The embankment structure is reinforced by grouting in stages based on the pressure data obtained by continuously monitoring pressure data using earth pressure sensors. The specific steps are as follows:

[0100] A pressure-time curve is generated based on the pressure data obtained from continuous monitoring, and a curvature threshold is preset.

[0101] The curvature of the pressure-time curve is calculated using the finite difference method, as shown in the following formula:

[0102]

[0103] In the formula: k is the curvature of the pressure-time curve; P i+1 P represents the grouting pressure at time i+1; iP represents the grouting pressure at time i; i-1 Let P be the grouting pressure at time i-1; max(P) is the maximum pressure value that occurs during the grouting process.

[0104] The threshold was determined by experimental calibration. Multiple grouting tests were conducted in the test section, and the complete pressure-time curve was recorded. The moment when obvious grout return or pressure surge occurred was determined, the corresponding curvature was calculated, and the results of multiple grouting tests were statistically analyzed to obtain the empirical curvature threshold.

[0105] When the curvature of the pressure-time curve is less than the curvature threshold, a reinforcement indicator point is identified, and grouting reinforcement operation is performed by injecting grout through the main and branch pipes of the grouting pipe; the change in the curvature of the curve is monitored in real time, and the grouting reinforcement operation ends when the curvature of the pressure-time curve is greater than or equal to the curvature threshold.

[0106] When the curvature of the pressure-time curve is less than the curvature threshold again, the next round of grouting reinforcement operation is started.

[0107] Repeat the monitoring of the grouting process until the curvature of the curve is stable and greater than or equal to the curvature threshold, confirming that the reinforcement is complete.

[0108] The advantages of using this embankment structure are:

[0109] 1. The refrigeration components in this structure use liquid coolant circulation to reduce the temperature of the surrounding frozen soil through the heat exchange pipes inside the threaded pile, thereby reducing the temperature of the permafrost around the threaded pile, preventing the foundation from melting, maintaining stability, and thus achieving the function of regulating the soil temperature.

[0110] 2. The heat exchange pipes inside the threaded pile can effectively transfer heat, reduce the temperature of frozen soil, and transfer heat to other parts, thereby realizing heat exchange between the inside of the pile and the outside soil.

[0111] 3. By utilizing solar panels on the ground to convert solar energy into electrical energy, the power generation components provide energy to the compressor in the refrigeration components, ensuring the energy self-sufficiency of the device;

[0112] 4. The temperature sensing component automatically controls the start and stop of the compressor through a temperature sensor and a microcontroller to ensure that the temperature around the threaded pile is maintained within the set range. The temperature sensor monitors the ambient temperature in real time. When the temperature is lower than the set value, the microcontroller starts the compressor and automatically adjusts the temperature of the frozen soil around the helical pile, thereby controlling the start and stop of the equipment.

[0113] Example 2, as follows Figure 7 , Figure 8 , Figure 9 and Figure 10As shown, the temperature-controlled pile-supported embankment structure with tie beams disclosed in this embodiment is completely consistent with that in Embodiment 1, except for the pile layer and the supporting heat exchange structure. The other connecting layer, cushion layer, geogrid layer, embankment layer, three major functional modules, main construction process, and dynamic grouting reinforcement method are all completely consistent with those in Embodiment 1. This embodiment focuses on explaining the core difference structure, and the general content will not be repeated.

[0114] In this embodiment, the pile body 11 of the helical pile is a hollow cylinder with a diameter that gradually decreases from top to bottom. The top is connected to the pile cap 12, and the bottom is connected to the pile tip 13. The pile cap is a cylindrical structure with water inlet and outlet holes on both sides. The pile tip is a conical structure to facilitate screwing into the frozen soil layer.

[0115] The threaded thread 14 spirals around the pile body 11 and is welded in place; the cross-section of the threaded thread is a hollow triangle.

[0116] The heat exchange pipe 15 is embedded in the cavity of the thread 14 and wound around the pile body along a spiral path. The heat exchange pipe is a copper pipe with an outer insulation layer to ensure heat exchange efficiency. The water inlet pipe of the heat exchange pipe passes through the water inlet hole, extends through the pile top interface to the pile bottom interface, and then extends vertically upwards through the water outlet hole to form a closed loop.

[0117] The helical pile in this embodiment is made of Q235B steel, with a pile length of 4m, an outer diameter of 220mm, and a wall thickness of 10mm.

[0118] The advantages of the threaded pile and internal heat exchange tube structure in this embodiment are higher heat transfer efficiency. The indirect heat exchange structure of "heat exchange tube built into the pile cavity and coolant filled into the pile cavity" in Embodiment 1 is adjusted to a direct heat exchange structure of "heat exchange tube embedded in the threaded hollow cavity". The heat exchange tube is spirally wound around the pile body along the thread, which completely changes the heat exchange path and heat exchange form. Its disadvantage is that the processing precision of the threaded heat exchange tube is higher and the production cost is higher. It is suitable for high-precision and long-cycle projects.

[0119] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A temperature-controlled pile-supported embankment structure with tie beams, characterized in that: It includes, from bottom to top, a layer of threaded piles, a connecting layer, a cushion layer, a geogrid layer, and an embankment layer; The threaded pile layer contains multiple vertical threaded piles, each including a pile body, pile cap, pile tip, and heat exchange channels inside the pile body. The connecting layer includes a grid structure formed by tie beams connecting adjacent pile caps, with an internal grouting pipe network; It also includes an energy supply module, an active temperature control module, and a monitoring and control module; The energy supply module includes a power generation unit and an energy storage unit, which supply power to each module; The active temperature control module includes a coolant circulation system connected to the heat exchange channel; The monitoring and control module includes an array of earth pressure sensors, an array of temperature sensors, and a control unit connected to the sensors. The control unit controls the operation of the active temperature control module based on the temperature sensor data and performs grouting reinforcement based on the earth pressure sensor data.

2. The temperature-controlled pile-supported embankment structure with tie beams as described in claim 1, characterized in that: The connecting layer includes a connecting cap, a tie beam, a main grouting pipe, and branch grouting pipes; both the connecting cap and the tie beam are made of reinforced concrete; the connecting cap is square and wraps around and fixes each pile cap; the tie beam connects adjacent connecting caps; each tie beam has a main grouting pipe embedded along its length; the inlet end of the grouting pipe extends to the outside of the embankment slope; multiple branch grouting pipes are evenly arranged on the main grouting pipe in the tie beam.

3. The temperature-controlled pile-supported embankment structure with tie beams as described in claim 1, characterized in that: The cushion layer includes a fine sand layer and a crushed stone cushion layer; the fine sand layer is laid on the upper surface of the connecting layer; the crushed stone cushion layer is laid on the fine sand layer, and soil pressure sensors are embedded therein; the soil pressure sensors are correspondingly set at the upper center and four corners of the connecting cap.

4. The temperature-controlled pile-supported embankment structure with tie beams as described in claim 1, characterized in that: The energy supply module includes a solar panel, a charging controller, and a battery pack connected in series; the solar panel is placed on the ground and is a monocrystalline silicon solar panel; the charging controller is a PWM type charging controller in solar charging controllers; the battery pack is an iron carbonate battery pack.

5. The temperature-controlled pile-supported embankment structure with tie beams as described in claim 1, characterized in that: The active temperature control module includes a refrigeration circuit consisting of a compressor, a condenser, and a throttling device; the outlet of the throttling device and the inlet of the compressor are respectively connected to the heat exchange tube.

6. The temperature-controlled pile-supported embankment structure with tie beams as described in claim 1, characterized in that: The temperature sensor array includes temperature sensors buried in the frozen soil around each threaded pile, each temperature sensor is connected to a microcontroller, and the microcontroller is connected to a compressor.

7. The temperature-controlled pile-supported embankment structure with tie beams as described in claim 1, characterized in that: The threaded pile body is a hollow cylinder, with a smooth upper section and a threaded lower section. The top is connected to the pile cap, and the bottom is connected to the pile tip. The pile cap is a cylindrical structure with openings on both sides through which heat exchange pipes pass and liquid inlet holes are provided. The pile tip is a conical structure. A heat exchange pipe is installed inside the hollow cavity of the threaded pile body. The heat exchange pipe is a copper pipe, and coolant flows through the pipe. The liquid inlet pipe of the heat exchange pipe passes through the hole on the pile cap, extends through the pile top interface to the pile bottom interface, and then extends vertically upward through the hole on the other side of the pile cap. The remaining space in the hollow cavity of the steel pipe threaded pile body is filled with coolant.

8. The temperature-controlled pile-supported embankment structure with tie beams as described in claim 1, characterized in that: The pile body is a hollow cylinder with a diameter that gradually decreases from top to bottom, with the pile cap connected to the top and the pile tip connected to the bottom. The pile cap is a cylindrical structure with inlet and outlet holes on both sides. The pile tip is a conical structure. The pile body is also provided with spiral threads that are fixed around the pile body. The cross-section of the threads is a hollow triangle. A heat exchange pipe is embedded in the cavity of the threads. The heat exchange pipe is a copper pipe covered with an insulation layer. The water inlet pipe of the heat exchange pipe passes through the inlet hole, extends through the pile top interface to the pile bottom interface, and then extends vertically upwards out of the outlet hole.

9. A method for constructing a temperature-controlled pile-supported embankment structure with tie beams as described in any one of claims 1-7, comprising the following specific steps: S1. Geological exploration and layout of threaded pile points Conduct site geological surveys, and determine the vertical placement points of the threaded piles based on the survey results and design loads; the spacing of the threaded piles is arranged in a grid pattern with a fixed center distance. S2. Threaded pile driving construction A static pressure boosting type rotary pile machine is used to vertically screw the threaded pile into the foundation, and the verticality deviation is monitored in real time during the screwing process; the top of the pile is above the ground, and the liquid inlet and outlet holes on both sides of the pile cap are exposed. S3, Temperature Sensing Component Installation First, temperature sensors are buried in the soil around the threaded piles, and measuring points are arranged at fixed intervals along the depth direction; then, the signal lines of the temperature sensors are led to the side of the connecting layer and connected to the microcontroller; finally, the sensor sensitivity is calibrated and the temperature threshold is set. S4, Installation of power generation and cooling components Connect the heat exchanger inlet pipe to the throttle outlet through the pile cap hole, and connect the outlet pipe to the compressor inlet through the other hole; inject coolant into the pile cavity through the pile cap inlet hole and seal it; check for leaks to ensure the sealing of the circulation pipeline and the pile cavity; fix the solar panel to the sunny side of the embankment and connect it to the battery pack through the charging controller; finally, complete the electrical connection between the compressor and the microcontroller. S5, Construction of connecting layer pouring Erect connecting caps and tie beam formwork at the top of the threaded piles, and tie the reinforcing cage; pre-embed the main and branch grouting pipes, with the main pipe inlet extending to the outside of the embankment slope; pour concrete, vibrate it to compact it, cover and cure it, and remove the formwork after the strength reaches the design requirements. S6. Layered filling construction A fine sand leveling layer is laid on the surface of the connecting layer, which is then manually leveled and mechanically compacted; a graded crushed stone cushion layer is laid, and earth pressure sensors are buried with a fixed spacing grid arrangement; a two-way plastic geogrid layer is laid, and U-shaped nails are used to anchor the joints; the embankment fill is filled in 5 layers, and the next layer can only be constructed after the compaction degree of each layer has been tested and qualified. S7, System Integration and Verification A comprehensive inspection was conducted on the helical pile, refrigeration components, power generation components, and temperature sensing components; the refrigeration components were started, and the circulation of coolant in the heat exchange tubes was observed; temperature sensor readings were monitored; temperature threshold triggering conditions were simulated to verify that the microcontroller could automatically start the compressor when the temperature was lower than the set temperature threshold; and finally, a pre-run verification was performed. S8, Subsequent dynamic grouting reinforcement The soil pressure sensor continuously monitors the pressure data, and the embankment structure is reinforced by grouting in stages based on the pressure data.

10. A method for dynamically grouting and reinforcing an embankment structure as described in claim 9, comprising the following specific steps: A pressure-time curve is generated based on continuously monitored pressure data, and a curvature threshold is preset; the curvature of the pressure-time curve is calculated using the following formula: In the formula: k is the curvature of the pressure-time curve; P i+1 P represents the grouting pressure at time i+1; i P represents the grouting pressure at time i; i-1 Let P be the grouting pressure at time i-1; max(P) is the maximum pressure value that occurs during the grouting process. The threshold was determined by experimental calibration. Multiple grouting tests were conducted in the test section, and the complete pressure-time curve was recorded. The moment when obvious grout return or pressure surge occurred was determined, the corresponding curvature was calculated, and the results of multiple grouting tests were statistically analyzed to obtain the empirical curvature threshold. When the curvature of the pressure-time curve is less than the curvature threshold, a reinforcement indication point is identified, and grouting reinforcement operation is performed by injecting grout through the main and branch pipes of the grouting pipe. The curvature change of the pressure-time curve is detected in real time. When the curvature of the pressure-time curve is greater than or equal to the curvature threshold, the grouting reinforcement operation is terminated. When the curvature of the pressure-time curve is less than the curvature threshold again, the next round of grouting reinforcement operation is started. Repeat the monitoring of the grouting process until the curvature of the curve is stable and greater than or equal to the curvature threshold, confirming that the reinforcement is complete.

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