Self-adaptive feedback anti-expansive soil intelligent pile foundation system

Abstract

The self-adaptive feedback type anti-expansive soil intelligent pile foundation system comprises a piezoelectric-hydraulic energy collecting device, a cathode drainage plate, an anode sleeve and a control module. The anode sleeve is arranged on the peripheral face of the foundation pile in a sleeving mode, the energy collecting device is installed between the foundation pile and the ground beam, and the cathode drainage plate is arranged around the foundation pile and opposite to the anode sleeve. When the pore water content of the expansive soil is higher than a threshold value, a direct-current electric field can be applied to a soil body by utilizing an electroosmotic flow principle to enable pore water to directionally migrate to a cathode and be discharged, so that the conversion from passive resistance to active steady-state regulation is realized; besides, a self-excited oscillation valve with a special structure is arranged in the energy collecting device, high-frequency vibration mechanical energy generated in the soil expansion process can be converted into high-frequency pulse alternating current through the piezoelectric effect, electric energy conversion and storage are completed through a control module, self-sufficiency of system electric energy is achieved, and the energy collecting device is high in energy utilization rate. The problem that traditional electroosmosis reinforcement needs to continuously consume a large amount of external electric energy is solved.

Description

Technical Field

[0001] This invention belongs to the field of expansive soil treatment technology, specifically relating to an adaptive feedback intelligent pile foundation system for anti-expansive soil. Background Technology

[0002] Expansive soil, rich in hydrophilic minerals such as montmorillonite, undergoes dramatic volume expansion and contraction under changes in moisture (its volume expands rapidly when exposed to water and shrinks significantly when dehydrated), leading to foundation deformation and infrastructure damage. It is known as a "hidden disaster" and causes enormous economic losses.

[0003] Traditional remediation techniques for expansive soils mainly focus on passive defense measures such as replacement and rigid cushion methods, as well as simple avoidance strategies like conventional pile foundations. Replacement involves excavating all or part of the expansive soil within a certain depth below the foundation, then backfilling in layers with high-strength, low-compressibility, non-expansive materials and compacting them to design requirements; this method is massive and subject to site limitations. Rigid cushion methods involve placing a layer of concrete or reinforced concrete slabs (cushions) with sufficient strength and rigidity on the expansive soil foundation, using its own rigidity to suppress uneven expansion and contraction deformation of the underlying soil. However, it often fails under strong expansion pressure due to stress redistribution. Conventional pile foundations, by driving or grouting concrete piles through the expansive soil layer, transfer the building load to deeper, stable, non-expansive soil or rock layers. However, they are easily sheared by the uplift force generated by soil heave.

[0004] Given the fundamental shortcomings of the aforementioned passive resistance strategies, the engineering community has shifted its research focus to proactive improvement, aiming to fundamentally alter or stabilize the soil itself. Examples include electro-osmotic reinforcement, chemical grout injection, and helical anchor reinforcement. However, current electro-osmotic reinforcement technologies require a continuous external DC power supply, resulting in enormous energy consumption and electrode corrosion; chemical grouts exhibit poor diffusion uniformity in low-permeability clays and pose environmental pollution risks; and helical anchor reinforcement technologies experience a gradual decrease in anchoring force under soil creep caused by continuous wet-dry cycles, lacking the ability to proactively sense and maintain steady-state regulation in response to environmental changes. Summary of the Invention

[0005] To overcome the aforementioned problems in the existing technology, this invention provides an adaptive feedback intelligent pile foundation system for expansive soil. By setting up an anode sleeve and a cathode drainage plate, when the pore water content of the expansive soil is higher than a threshold, the principle of electroosmosis can be used to apply a DC electric field in the soil to cause the pore water to migrate directionally to the cathode and be discharged, thereby realizing the transformation from passive resistance to active steady-state regulation. At the same time, by setting up a self-excited oscillation valve with a special structure, the high-frequency vibration mechanical energy generated during the soil expansion process can be converted into high-frequency pulsed alternating current using the piezoelectric effect. The energy conversion and storage are completed by the control module, realizing the self-sufficiency of the system's electrical energy and solving the problem that traditional electroosmotic reinforcement requires a large amount of external electrical energy to be continuously consumed.

[0006] The technical solution of this application is as follows:

[0007] An adaptive feedback intelligent pile foundation system for anti-expansion soil includes an anode sleeve, a cathode drainage plate, and a piezoelectric-hydraulic energy harvesting device. The anode sleeve is fitted onto the outer circumference of the pile, the energy harvesting device is installed between the pile and the ground beam, and the cathode drainage plate is arranged around the pile. The energy harvesting device includes a mounting base and a self-excited oscillation valve mounted on the mounting base. The self-excited oscillation valve includes a valve body and a strong magnetic element within the valve body. A magnetic threshold plate is attracted to the strong magnetic element, dividing the interior of the valve body into a hydraulic chamber and a pressure relief chamber. The hydraulic chamber... An internal spring is provided, with one end of the spring connected to the valve body via a mounting plate and the other end connected to a magnetic threshold plate via a moving rod. Impact heads and piezoelectric stacks are distributed opposite each other within the pressure relief chamber. The impact heads are fixed to the magnetic threshold plate, and the piezoelectric stacks are fixed to the valve body. The valve body has an inlet for connecting the hydraulic chamber and the hydraulic bearing bladder, and a pressure relief port for connecting the pressure relief chamber and the recovery tank. The recovery tank is connected to the hydraulic bearing bladder via a one-way valve circuit. The anode sleeve, cathode drain plate, and piezoelectric stack are respectively connected to the control module.

[0008] When the expansive soil around the pile absorbs water and bulges, it squeezes the hydraulic bearing bladder, causing the hydraulic oil inside to flow into the hydraulic chamber of the valve body, pushing the magnetic threshold plate. When the hydraulic thrust exceeds the magnetic attraction threshold, the magnetic threshold plate disconnects from the strong magnetic element. At this moment, the impact head violently strikes the piezoelectric stack, exciting it to generate high-frequency inherent resonance, modulating low-frequency mechanical energy into high-frequency pulsed AC and inputting it into the control module. The control module converts the AC to DC and stores it. Simultaneously, the hydraulic oil in the hydraulic chamber rushes into the pressure relief chamber and flows back to the oil tank from the pressure relief port, causing the pressure inside the chamber to drop. The magnetic threshold plate is reset under the action of the spring and is once again attracted and locked by the strong magnetic element, entering the next cycle.

[0009] Compared with existing technologies, the adaptive feedback intelligent pile foundation system for expansive soil of this application, by setting up an anode sleeve and a cathode drainage plate, can apply a DC electric field to the soil when the pore water content of the expansive soil is higher than the threshold, using the principle of electroosmosis to cause the pore water to migrate directionally to the cathode and be discharged. This realizes the transformation of expansive soil treatment technology from passive resistance to active steady-state regulation. At the same time, by setting up a self-excited oscillation valve with a special structure, the expansive damage energy of the soil itself can be converted into treatment energy (specifically, the high-frequency vibration mechanical energy generated during the soil expansion process is converted into high-frequency pulsed AC power, and then converted into DC power and stored by the control module), realizing the self-sufficiency of the system's electrical energy. This solves the problem that traditional electroosmotic reinforcement requires a large amount of external electrical energy to be continuously consumed, and makes the system green, environmentally friendly and zero-carbon operation.

[0010] As an optimization, in the aforementioned adaptive feedback intelligent pile foundation system for expansive soil, the control module includes a rectifier circuit, a voltage regulator circuit, and a supercapacitor module. This module converts the high-frequency pulsed AC power input from the piezoelectric stack into DC power and stores it in the supercapacitor module. Supercapacitor modules offer advantages such as long charge-discharge cycle life, slow performance degradation, and strong environmental adaptability. Using a supercapacitor module to store DC power results in high power density, enables rapid charging and discharging of large currents, adapts to high-frequency pulsed energy input, and offers high reliability, meeting the long-term operational requirements of the system.

[0011] As an optimization, in the aforementioned adaptive feedback anti-expansion soil intelligent pile foundation system, the anode sleeve is equipped with a temperature-sensitive variable friction self-healing layer made of geotextile grafted with poly(N-isopropylacrylamide) temperature-sensitive hydrogel, and a resistance wire heating mesh is embedded inside; the resistance wire heating mesh is connected to the control module. Thus, the phase transition characteristics of the temperature-sensitive hydrogel around its lowest critical dissolution temperature (LCST) can be utilized to switch between "lubrication / locking" modes: when the soil moisture content increases with an upward pull-out tendency, the low-temperature swelling characteristics of the temperature-sensitive hydrogel form a super-hydrophilic lubricating layer, reducing the friction coefficient at the pile-soil interface, causing the pile to "slip" when the soil heaves, thereby decoupling the upward pull-out force and protecting the pile from cracking. Under load-bearing conditions, the resistance wire heating mesh is energized, raising the interface temperature of the temperature-sensitive variable friction self-healing layer above the LCST, causing the temperature-sensitive hydrogel to lose water, shrink, and harden, restoring high friction and locking the pile body; thus effectively avoiding pull-out damage to the pile caused by expansive soil while ensuring the necessary bearing capacity. Furthermore, a set of limiting protrusions are spaced apart on the outer surface of the anode sleeve, and a temperature-sensitive friction self-healing layer is provided between two adjacent limiting protrusions. This results in a simple structure, convenient assembly, and avoids the anode sleeve being completely covered by the insulating temperature-sensitive friction self-healing layer.

[0012] As an optimization, the aforementioned adaptive feedback anti-expansion soil smart pile foundation system also includes an external power supply module, which is used to supplement the system with power when the supercapacitor module's energy storage is insufficient, thereby ensuring the reliable operation of the system under special working conditions such as insufficient energy collection.

[0013] As an optimization, in the aforementioned adaptive feedback anti-expansion soil intelligent pile foundation system, the piezoelectric stack consists of a set of PZT piezoelectric ceramics and metal electrodes stacked alternately. The piezoelectric stack adopts the above-mentioned layered structural design, which can achieve cumulative large displacement output under low driving voltage, avoiding the problem of insufficient displacement of a single piezoelectric ceramic. Furthermore, the overall structure is compact, and the energy conversion and transfer stability is good.

[0014] As an optimization, in the aforementioned adaptive feedback anti-expansion soil intelligent pile foundation system, the anode sleeve is made of conductive carbon fiber composite material, and the cathode drainage board is made of conductive plastic material. The anode sleeve, made of conductive carbon fiber composite material, possesses excellent conductivity and mechanical strength, outstanding resistance to acid and alkali corrosion, and superior deformation resistance. The cathode drainage board, made of conductive plastic material, ensures conductive pathways while also considering the formability and toughness of the drainage structure, and its low material density and ease of processing contribute to improved overall system performance and reduced operation and maintenance costs.

[0015] As an optimization, in the aforementioned adaptive feedback anti-expansion soil intelligent pile foundation system, the mounting base is disc-shaped and fixed to the top of the pile, the hydraulic bearing bladder is annular and fitted over the pile, and the self-excited oscillation valve is located between the mounting base and the hydraulic bearing bladder. This design facilitates assembly and reduces implementation difficulty.

[0016] As an optimization, the aforementioned adaptive feedback anti-expansion soil intelligent pile foundation system uses sensors embedded in the soil to monitor the moisture content of the expansive soil around the pile in real time during use, and sends the data to the control module. When the moisture content exceeds the warning threshold, the control module applies intermittent pulsed DC current to the anode sleeve and cathode drainage plate. Based on the principle of electroosmosis, the pore water around the pile is driven to migrate directionally from the anode sleeve to the cathode drainage plate for discharge. When the moisture content continues to decrease, the control module energizes the resistance wire heating mesh, raising the interface temperature of the temperature-sensitive variable friction self-healing layer above the minimum critical dissolution temperature. The temperature-sensitive hydrogel loses water, shrinks, and hardens, increasing the surface roughness of the pile side. This increases the pile body locking by increasing the pile-soil interfacial friction resistance, thereby enhancing the bearing stability of the pile. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the adaptive feedback anti-expansion soil intelligent pile foundation system in the embodiments of this application;

[0018] Figure 2This is a schematic diagram of the assembly of the anode sleeve and the temperature-sensitive friction self-healing layer in the embodiments of this application;

[0019] Figure 3 This is a schematic diagram of the structure of the self-excited oscillation valve in the embodiments of this application.

[0020] The markings in the attached diagram are as follows: 1-foundation pile; 2-anode sleeve; 21-limiting ridge; 3-cathode drainage plate; 4-mounting base; 5-self-excited oscillation valve; 51-valve body; 52-strong magnetic element; 53-magnetic threshold plate; 54-spring; 55-mounting plate; 56-moving rod; 57-impact head; 58-piezoelectric stack; 501-hydraulic chamber; 502-pressure relief chamber; 503-inlet; 504-pressure relief port; 6-hydraulic bearing bladder; 7-recovery box; 8-temperature-sensitive friction self-healing layer. Detailed Implementation

[0021] The present application will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present application. Contents not described in detail in the following embodiments are all common knowledge in the art.

[0022] To address the technical problems in existing expansive soil remediation technologies, such as poor passive defense effects, high energy consumption and unsustainable active remediation methods, and the inability of the pile-soil interface to adapt to the dynamic expansion and contraction of the soil, this invention provides an adaptive feedback intelligent pile foundation system for expansive soil remediation. This system requires no external power supply, converts the soil's own expansion and destructive energy into remediation energy, and adaptively adjusts pile side friction and removes pore water based on soil moisture content. This transforms expansive soil remediation technology from passive resistance to active steady-state regulation. The specific structure is as follows.

[0023] Example:

[0024] See Figures 1 to 3The adaptive feedback anti-expansion soil intelligent pile foundation system in this embodiment includes an anode sleeve 2, a cathode drainage plate 3, and a piezoelectric-hydraulic energy harvesting device. The anode sleeve 2 is sleeved on the outer circumferential surface of the pile 1, the energy harvesting device is installed between the pile 1 and the ground beam, and the cathode drainage plate 3 is arranged around the pile 1 and distributed opposite to the anode sleeve 2. The energy harvesting device includes a mounting base 4 and a self-excited oscillation valve 5 (multiple self-excited oscillation valves 5 are provided on the mounting base 4 and are evenly distributed at circumferential intervals at the bottom of the mounting base 4). The self-excited oscillation valve 5 includes a valve body 51 and a strong magnetic element 52 (e.g., a magnet) fixed on the inner wall of the valve body 51. A magnetic threshold plate 53 is attracted and connected to the strong magnetic element 52, dividing the interior of the valve body 51 into a hydraulic chamber 501 and a pressure relief chamber 502 (initially, the hydraulic chamber 501 and the pressure relief chamber 502 are not connected). A spring 54 is provided inside the hydraulic chamber 501. One end of the spring 54 is connected to the valve body 51 via a mounting plate 55 (the end of the spring 54 is fixed to the mounting plate 55, which is fixed to the inner wall of the valve body 51), and the other end is connected to the magnetic threshold plate 53 via a moving rod 56. An impact head 57 and a piezoelectric stack 58 are distributed opposite each other in the pressure relief chamber 502. The impact head 57 is fixed to the magnetic threshold plate 53, and the piezoelectric stack 58 is fixed to the valve body 51. The valve body 51 has an inlet 503 for connecting the hydraulic chamber 501 and the hydraulic bearing bladder 6, and a pressure relief port 504 for connecting the pressure relief chamber 502 and the recovery box 7. The recovery box 7 is connected to the hydraulic bearing bladder 6 via a one-way valve circuit. The anode sleeve 2, the cathode drain plate 3, and the piezoelectric stack 58 are respectively connected to the control module (the control module can be installed inside the mounting base 4).

[0025] Working principle: When the expansive soil around the pile absorbs water and bulges, it squeezes the hydraulic bearing bladder 6, causing the hydraulic oil inside to flow from the inlet 503 of the valve body 51 into the hydraulic chamber 501, pushing the magnetic threshold plate 53 (because the magnetic threshold plate 53 is attracted and fixed by the strong magnetic element 52, it prevents the hydraulic oil from pushing; at this time, the slow quasi-static mechanical work of the soil will be converted into the accumulation of fluid potential energy); when the hydraulic thrust breaks through the magnetic attraction threshold, the magnetic threshold plate 53 is pushed and disconnected from the strong magnetic element 52. At this time, the impact head 57 uses the accumulated potential energy to accelerate and eject instantly, thereby violently impacting the piezoelectric stack 58, exciting it to generate high-frequency inherent resonance, modulating the low-frequency mechanical energy into high-frequency pulse AC and inputting it into the control module. The control module converts the AC to DC and stores it. At the same time, the hydraulic oil in the hydraulic chamber 501 will rush into the pressure relief chamber 502 and flow into the return oil tank 7 from the pressure relief port 504 (the hydraulic oil flow direction is as follows). Figure 3As shown; after the hydraulic oil enters the recovery tank 7, it flows back to the hydraulic bearing bladder 6 through the one-way valve circuit, causing the pressure inside the cavity to drop. The magnetic threshold plate 53 is reset under the action of the spring 54 and is once again attracted and locked by the strong magnetic element 52, entering the next cycle. This process can achieve self-sufficiency of system electrical energy.

[0026] In this embodiment, the control module includes a rectifier circuit, a voltage regulator circuit, and a supercapacitor module, which is used to convert the high-frequency pulse AC power input from the piezoelectric stack 58 into DC power and store it in the supercapacitor module.

[0027] In this embodiment, the anode sleeve 2 is provided with a temperature-sensitive variable friction self-healing layer 8, which is made of geotextile grafted with poly(N-isopropylacrylamide) temperature-sensitive hydrogel (PNIPAM temperature-sensitive hydrogel; the minimum critical dissolution temperature is about 32°C) (that is, a high-strength geotextile is used as the skeleton, and PNIPAM temperature-sensitive hydrogel is grafted onto the fiber surface), and a resistance wire heating mesh is embedded inside; the resistance wire heating mesh is connected to the control module and is used to regulate the interface temperature of the temperature-sensitive variable friction self-healing layer 8. Therefore, when the soil moisture content increases (during low temperature / humid period, T<32°C; the power supply to the resistance wire heating mesh is off), the PNIPAM thermosensitive hydrogel absorbs water and swells, forming a super-hydrophilic lubricating layer. This reduces the friction coefficient at the pile-soil interface, causing the pile to "slip" when the soil heaves, thus decoupling the pull-out force and protecting the pile foundation from cracking. When the soil is in the water loss and shrinkage period, the control module uses stored electrical energy to activate the resistance wire heating mesh, raising the interface temperature to above 32°C. At this time, the PNIPAM thermosensitive hydrogel undergoes a phase change, shrinking drastically and draining water. This hardens the surface of the thermosensitive variable friction self-healing layer 8 and increases its roughness, thereby restoring the pile side friction resistance and locking the pile body. This effectively avoids pull-out damage to the pile 1 caused by expansive soil while ensuring the necessary bearing capacity. See also Figure 2 The outer surface of the anode sleeve 2 is provided with four circumferentially spaced limiting protrusions 21 (the limiting protrusions 21 have a structure that is narrow at the top and wide at the root), and a temperature-sensitive friction self-healing layer 8 is provided between two adjacent limiting protrusions 21. At this time, the structure is simple, the assembly is convenient, and the anode sleeve 2 can be prevented from being completely covered by the insulating temperature-sensitive friction self-healing layer 8.

[0028] In this embodiment, an external power supply module is also included to provide supplemental power to the system when the supercapacitor module has insufficient energy storage, thereby ensuring the reliable operation of the system under special conditions such as insufficient energy harvesting.

[0029] In this embodiment, the piezoelectric stack 58 is composed of a set of alternating stacked PZT piezoelectric ceramics and metal electrodes. The piezoelectric stack 58 adopts a multi-layer PZT piezoelectric ceramics and metal electrode alternating stacked structure design, which can achieve cumulative large displacement output under low driving voltage, avoid the problem of insufficient displacement of a single piezoelectric ceramic, and has a compact overall structure with good energy conversion and transfer stability.

[0030] In this embodiment, the anode sleeve 2 is made of conductive carbon fiber composite material, and the cathode drainage plate 3 is made of conductive plastic material. The anode sleeve 2, made of conductive carbon fiber composite material, possesses excellent conductivity and mechanical strength, outstanding resistance to acid and alkali corrosion, and superior deformation resistance. The cathode drainage plate 3, made of conductive plastic material, ensures a conductive path while also considering the formability and toughness of the drainage structure, and its low material density and ease of processing contribute to improved overall system performance and reduced maintenance costs.

[0031] In this embodiment, the mounting base 4 is disc-shaped and fixed to the top of the foundation pile 1; the hydraulic bearing bladder 6 is annular and sleeved on the outside of the foundation pile 1; the self-excited oscillation valve 5 is located between the mounting base 4 and the hydraulic bearing bladder 6; the top of the mounting base 4 is also provided with an installation component for connecting to the ground beam. This design facilitates assembly and reduces implementation difficulty.

[0032] In this embodiment, the adaptive feedback anti-expansion soil intelligent pile foundation system uses sensors pre-embedded in the soil (the sensors are pre-embedded during the foundation treatment construction process) to monitor the moisture content of the expansive soil around the pile 1 in real time and send the data to the control module. When the moisture content exceeds the warning threshold, the control module applies intermittent pulsed DC current to the anode sleeve 2 and the cathode drainage plate 3. Based on the principle of electroosmosis, the pore water around the pile is driven to migrate directionally from the anode sleeve 2 to the cathode drainage plate 3 for discharge. When the moisture content continues to decrease, the control module energizes the resistance wire heating mesh, raising the interface temperature of the temperature-sensitive variable friction self-healing layer 8 to above the minimum critical dissolution temperature, causing the temperature-sensitive hydrogel to lose water, shrink, and harden, thereby improving the surface roughness of the pile side.

[0033] The foregoing general description of the invention and its specific embodiments should not be construed as a limitation on the technical solution of the invention. Those skilled in the art, based on the disclosure of this application, can add, reduce, or combine the disclosed technical features in the foregoing general description and / or specific embodiments (including examples) without departing from the constituent elements of the invention, to form other technical solutions within the scope of protection of this application.

Claims

1. An adaptive feedback-based intelligent pile foundation system for anti-expansion soil, characterized in that: The device includes an anode sleeve (2), a cathode drainage plate (3), and a piezoelectric-hydraulic energy harvesting device. The anode sleeve (2) is fitted onto the outer circumference of the foundation pile (1), the energy harvesting device is installed between the foundation pile (1) and the ground beam, and the cathode drainage plate (3) is arranged around the foundation pile (1). The energy harvesting device includes a mounting base (4) and a self-excited oscillation valve (5) mounted on the mounting base (4). The self-excited oscillation valve (5) includes a valve body (51) and a strong magnetic element (52) inside the valve body (51). A magnetic threshold plate (53) is attached to the strong magnetic element (52), dividing the interior of the valve body (51) into a hydraulic chamber (501) and a pressure relief chamber (502). A spring (54) is provided inside the hydraulic chamber (501), and one end of the spring (54) is connected to a mounting base. The mounting plate (55) is connected to the valve body (51), and the other end is connected to the magnetic threshold plate (53) via the moving rod (56); the pressure relief chamber (502) contains an impact head (57) and a piezoelectric stack (58) distributed opposite to each other; the impact head (57) is fixed on the magnetic threshold plate (53), and the piezoelectric stack (58) is fixed on the valve body (51); the valve body (51) has an inlet (503) for connecting the hydraulic chamber (501) and the hydraulic bearing bladder (6), and a pressure relief port (504) for connecting the pressure relief chamber (502) and the recovery box (7); the recovery box (7) is connected to the hydraulic bearing bladder (6) via a one-way valve circuit; the anode sleeve (2), the cathode drain plate (3), and the piezoelectric stack (58) are respectively connected to the control module.

2. The adaptive feedback-type anti-expansion soil intelligent pile foundation system according to claim 1, characterized in that: The control module includes a rectifier circuit, a voltage regulator circuit, and a supercapacitor module, which is used to convert the high-frequency pulse AC power input from the piezoelectric stack (58) into DC power and store it in the supercapacitor module.

3. The adaptive feedback-type anti-expansion soil intelligent pile foundation system according to claim 2, characterized in that: The anode sleeve (2) is provided with a temperature-sensitive friction self-healing layer (8), which is made of geotextile grafted with poly(N-isopropylacrylamide) temperature-sensitive hydrogel, and has a resistance wire heating mesh embedded inside; the resistance wire heating mesh is connected to the control module.

4. The adaptive feedback-type anti-expansion soil intelligent pile foundation system according to claim 3, characterized in that: A set of limiting protrusions (21) are provided at intervals on the outer surface of the anode sleeve (2), and a temperature-sensitive friction self-healing layer (8) is provided between two adjacent limiting protrusions (21).

5. The adaptive feedback-type anti-expansion soil intelligent pile foundation system according to claim 3, characterized in that: It also includes an external power supply module, which is used to supplement the system with power when the supercapacitor module's energy storage is insufficient.

6. The adaptive feedback-type anti-expansion soil intelligent pile foundation system according to claim 3, characterized in that: The piezoelectric stack (58) consists of a set of PZT piezoelectric ceramics and metal electrodes stacked alternately.

7. The adaptive feedback-type anti-expansion soil intelligent pile foundation system according to claim 3, characterized in that: The anode sleeve (2) is made of conductive carbon fiber composite material, and the cathode drainage plate (3) is made of conductive plastic material.

8. The adaptive feedback-type anti-expansion soil intelligent pile foundation system according to claim 3, characterized in that: The mounting base (4) is disc-shaped and fixed to the top of the foundation pile (1). The hydraulic bearing bladder (6) is annular and sleeved on the outside of the foundation pile (1). The self-excited oscillation valve (5) is located between the mounting base (4) and the hydraulic bearing bladder (6).

9. The adaptive feedback-type anti-expansion soil intelligent pile foundation system according to claim 1 is characterized in that: During use, the moisture content of the expansive soil around the pile (1) is monitored in real time by sensors embedded in the soil and sent to the control module. When the moisture content exceeds the warning threshold, the control module applies intermittent pulsed DC current to the anode sleeve (2) and the cathode drainage plate (3). Based on the principle of electroosmosis, the pore water around the pile is driven to migrate directionally from the anode sleeve (2) to the cathode drainage plate (3) and discharged.

10. The adaptive feedback-type anti-expansion soil intelligent pile foundation system according to claim 3, characterized in that: During use, the sensors embedded in the soil monitor the moisture content of the expansive soil around the pile (1) in real time and send it to the control module. When the moisture content exceeds the warning threshold, the control module applies intermittent pulsed DC current to the anode sleeve (2) and the cathode drainage plate (3). Based on the principle of electroosmosis, the pore water around the pile is driven to migrate directionally from the anode sleeve (2) to the cathode drainage plate (3) and discharged. When the moisture content continues to decrease, the control module powers the resistance wire heating mesh, so that the interface temperature of the temperature-sensitive variable friction self-healing layer (8) rises above the minimum critical dissolution temperature, and the temperature-sensitive hydrogel loses water, shrinks and hardens.

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