A deformed active adjusting steel pipe pile supporting structure and a foundation pit enclosure construction method

Abstract

The application discloses a deformed active adjusting steel pipe pile supporting structure and a foundation pit enclosure construction method, and relates to the field of foundation pit enclosure construction. The structure comprises a hollow pipe pile, a plurality of loading openings are arranged on the same side wall of the pipe pile in an axial direction, a radial sliding push plate is arranged outside the pipe pile corresponding to each loading opening, a radial guide mechanism is arranged between the push plate and the pipe pile, an axial guide rail is arranged in the pipe pile, at least one active pushing mechanism is slidably arranged on the guide rail, and the jacking rod of the active pushing mechanism pushes the push plate outward through the loading opening. The structure applies a horizontal pre-pressure through the active pushing mechanism before the foundation pit is excavated, compensates for the stress release of the soil body in advance, realizes real-time adjustment of the pre-axial force in combination with layered excavation, reduces the deformation of the enclosure structure, avoids the settlement of surrounding buildings, is suitable for sensitive scenes such as soft soil areas, and the equipment can be reused, and the construction is efficient.

Description

Technical Field

[0001] This invention relates to foundation pit retaining construction, specifically to a deformation-adjustable steel pipe pile support structure and a foundation pit retaining construction method. Background Technology

[0002] In deep foundation pit engineering, traditional support structures (such as bored piles, diaphragm walls, and SMW method piles) mainly rely on passive force mechanisms, that is, providing restraint through internal bracing or anchor cables after the retaining structure deforms. However, such methods apply support forces after soil excavation, which cannot pre-counter the displacement caused by the release of soil pressure, easily leading to uneven settlement of surrounding buildings or tunnels; in addition, the construction and maintenance cycle of the support structure is long. Due to the significant spatiotemporal effects in soft soil areas, soil creep further exacerbates the deformation of the surrounding environment of the foundation pit. Summary of the Invention

[0003] To address the aforementioned problems, this invention proposes a deformation-actively-adjustable steel pipe pile support system and construction method. Before excavation, horizontal preload is applied to the steel pipe piles using jacks to compensate for stress release caused by subsequent soil excavation, reducing deformation of the retaining structure. Combined with layered excavation and step-by-step loading by jacks, real-time adjustment of the preloaded axial force is achieved, ensuring the safety of the foundation pit. The specific scheme is as follows:

[0004] A deformation-adjustable steel pipe pile support structure, comprising hollow pipe piles,

[0005] Several loading ports are spaced apart along the axial direction on the side wall of the hollow pipe pile. A radially sliding push plate is configured on the outer side wall of the hollow pipe pile corresponding to each loading port. A radial guide mechanism is connected between the push plate and the hollow pipe pile.

[0006] Axially distributed guide rails are installed inside the hollow pipe pile, and at least one active propulsion mechanism is slidably installed on the guide rails. The active propulsion mechanism is equipped with a push rod, which pushes the push plate outward through the loading port to control the deformation of the retaining structure.

[0007] Furthermore, hollow pipe piles can be circular, rectangular, or square steel pipe piles;

[0008] The side of the push plate closest to the hollow pipe pile is in contact with the outer wall of the hollow pipe pile.

[0009] Furthermore, the radial guiding mechanism includes a guide hole and a guide post;

[0010] Hollow pipe piles have guide holes on both sides of each loading port that are aligned with the sliding direction of the push plate. A guide column that slides through the guide hole is fixed on the side of the push plate closest to the hollow pipe pile.

[0011] Furthermore, a first pad block is provided on the side of the push plate near the hollow pipe pile, which coincides radially with the loading port;

[0012] When the push plate is in contact with the outer wall of the hollow pipe pile, the first pad block extends into the loading port.

[0013] Furthermore, several second pads are fixed axially inside the hollow pipe pile, each second pad corresponding to a different loading port and distributed 180° opposite to each other inside the hollow pipe pile.

[0014] Furthermore, multiple adjacent push plates are fixedly connected as a single push plate.

[0015] Furthermore, the active propulsion mechanism is a servo jack.

[0016] Furthermore, an active propulsion mechanism is installed inside each loading port of the hollow pipe pile, and multiple active propulsion mechanisms are connected in series by steel strands.

[0017] Furthermore, only one active propulsion mechanism is installed inside the hollow pipe pile, and the active propulsion mechanism is connected to the lifting drive mechanism.

[0018] A construction method for a deformation-actively adjustable steel pipe pile support structure includes the following steps:

[0019] S1. Hollow pipe piles are driven to the design depth. Several loading ports are spaced apart along the axial direction on the side wall of the same side of the hollow pipe pile. A radially sliding push plate is configured on the outer side wall of the hollow pipe pile corresponding to each loading port. A radial guide mechanism is connected between the push plate and the hollow pipe pile. An axially distributed guide rail is installed inside the hollow pipe pile. At least one active propulsion mechanism is slidably installed on the guide rail. The active propulsion mechanism is equipped with a push rod. The push rod pushes the push plate outward through the loading port.

[0020] S2. Before the foundation pit is excavated, at least one active propulsion mechanism is activated to apply horizontal preload to the push plate at the corresponding height through the push rod, so as to compensate for the release of soil excavation stress in advance.

[0021] S3. As the foundation pit is excavated in layers, the pre-applied axial force of the active propulsion mechanism is adjusted in real time to control the deformation of the retaining structure.

[0022] S4. After the basement structure has achieved rigidity, the active propulsion mechanism is gradually unloaded and removed from the hollow pipe pile.

[0023] Furthermore, the active propulsion mechanism is a servo jack; in steps S2-S3, a servo jack is installed in each loading port inside the hollow pipe pile, and multiple servo jacks are connected in series by steel strands; as the foundation pit is excavated in layers, the servo jacks at the corresponding heights are controlled synchronously or individually to adjust the pre-applied axial force in real time.

[0024] Furthermore, only one active propulsion mechanism is provided inside the hollow pipe pile, and the active propulsion mechanism is connected to the lifting drive mechanism; in steps S2-S3, before the foundation pit is excavated, the active propulsion mechanism is lowered to the height corresponding to the uppermost loading port and pre-pressure is applied. As each layer of earthwork is excavated and before the construction of the next horizontal support is completed, the active propulsion mechanism is moved to the height of the corresponding loading port through the lifting drive mechanism and the adjustment force is reapplied until the foundation pit is excavated to the bottom.

[0025] Compared with traditional support structures, this deformation-actively-adjustable steel pipe pile support structure has the following significant advantages:

[0026] 1. Before the foundation pit is excavated, a horizontal preload is applied to the steel pipe piles using an active propulsion mechanism (such as a servo jack) to compensate for the stress release caused by subsequent soil excavation, thereby reducing the deformation of the retaining structure from the source. Traditional support structures require support constraints after deformation occurs, which can easily lead to uneven settlement of surrounding buildings, tunnels, etc. This structure can intervene in advance, making it particularly suitable for deformation-sensitive scenarios such as soft soil areas.

[0027] 2. As the excavation depth of the foundation pit increases, the pre-applied axial force can be adjusted in real time through the active propulsion mechanism at the corresponding height (or by moving a single mechanism to the corresponding position) to fill the deformation gap during the construction of the horizontal support and ensure the stability of the retaining structure at each stage.

[0028] 3. It can achieve full-height, full-process control through multiple series-connected active propulsion mechanisms (suitable for high-requirement scenarios), or it can use a single mechanism for mobile reuse (suitable for low-cost, low-requirement scenarios), adapting to different construction needs.

[0029] 4. The radial guiding mechanism (guide hole + guide post) restricts the direction of the push plate movement to ensure that the thrust is applied precisely in the radial direction; the first pad and the second pad optimize the point of application of the force and the support of the reaction force, respectively, to avoid local stress concentration.

[0030] 5. Active propulsion mechanisms (such as servo jacks) can be removed from the pipe pile after construction and reused in other projects, reducing equipment costs. No complex support and maintenance procedures are required, and combined with the rapid construction characteristics of steel pipe piles, the overall construction period is shortened, making it particularly suitable for projects sensitive to construction schedules.

[0031] 6. By maintaining the stability of the retaining structure through prestressing, it can effectively balance soil pressure and reduce the risk of collapse even before the basement structure has developed rigidity. It has a significant protective effect on surrounding buildings, tunnels, etc., and can be applied to deep foundation pit projects in complex environments such as urban core areas and areas surrounding existing buildings. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the deformation-actively-adjustable steel pile support structure in Embodiment 1 of the present invention;

[0034] Figure 2 This is a schematic diagram of the plan layout of the deformation-actively-adjustable steel pile support structure in Embodiment 1 of the present invention;

[0035] Figure 3 This is a schematic cross-sectional view of the steel pile support structure with active deformation adjustment in Embodiment 1 of the present invention.

[0036] Figure 4 This is a schematic diagram of a hollow pipe pile with a push plate attached to its outer wall, as shown in Embodiment 1 of the present invention.

[0037] Figure 5 This is a schematic diagram of a long push plate that highly covers multiple loading ports in Embodiment 1 of the present invention;

[0038] Figure 6 This is a schematic diagram of a hollow pipe pile with multiple loading ports on its sidewall, as shown in Embodiment 1 of the present invention.

[0039] Figure 7 This is a schematic diagram of an active propulsion mechanism installed inside a hollow pipe pile in Embodiment 1 of the present invention;

[0040] Figure 8 This is a partial schematic diagram of the hollow pipe pile in Embodiment 1 of the present invention;

[0041] Figure 9 This is a schematic diagram of a short pusher plate that covers only a single loading port in Embodiment 1 of the present invention;

[0042] Figure 10 This is a schematic diagram of the construction steps of the steel pile support structure with active deformation adjustment in Embodiment 2 of the present invention. Detailed Implementation

[0043] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0044] To fully understand this invention, detailed steps and structures will be presented in the following description to illustrate the technical solution of this invention. Preferred embodiments of the invention are described in detail below; however, in addition to these detailed descriptions, the invention may have other embodiments.

[0045] Example 1

[0046] Reference Figure 1-9 As shown, this invention provides a deformation-actively adjustable steel pipe pile support structure. Its core is the precise control of the deformation of the foundation pit retaining structure through components capable of actively applying force. The structure includes hollow pipe piles 4, with several hollow pipe piles 4 arranged at preset intervals to collectively form the steel pipe pile support structure 1, creating the first protective barrier around the foundation pit. The hollow pipe piles serve as the foundation carrier of the entire support structure, and their length and diameter are determined based on design parameters such as the foundation pit depth and the properties of the surrounding soil.

[0047] Along the axial direction, several loading ports 10 are spaced apart on the sidewall of the hollow pipe pile 4. The spacing of the loading ports is designed according to the height of the layered excavation of the foundation pit (usually corresponding to the setting height of the horizontal supports) so as to apply adjustment forces to the retaining structure at different depths at different excavation stages. On the outer sidewall of the hollow pipe pile 4, a push plate 5 that can slide radially is provided for each loading port 10.

[0048] In this embodiment, the shape of the hollow pipe pile 4 can be selected according to actual construction needs; circular, rectangular, or square steel pipe piles are all suitable. For example, Figure 4 The diagram illustrates a hollow pipe pile 4 using a circular steel pipe. In this case, the push plate 5 is designed as a fan-shaped plate, with the curvature of its inner arc surface perfectly matching the curvature of the outer wall of the hollow pipe pile, ensuring a tight fit between the push plate and the outer wall of the pipe pile. The advantages of this fit design are: when the push plate is not under load, it reduces the gap between it and the pipe pile, preventing the entry of debris such as soil and gravel during construction; and when the push plate is under load and moves outward, it ensures the uniform transmission of the initial thrust, preventing localized stress concentration that could lead to deformation of the pipe pile or the push plate. If a rectangular or square steel pipe pile is used, the push plate is correspondingly designed as a flat plate, with its inner plane fitting against the outer wall plane of the pipe pile, operating on the same principle.

[0049] A radial guiding mechanism connects the push plate 5 and the hollow pipe pile 4. This structure restricts the movement direction of the push plate, ensuring that it can only move radially perpendicular to the axis of the pipe pile, avoiding force transmission deviation caused by push plate offset, thereby ensuring the precise application of the adjusting force. More preferably, the radial guiding mechanism specifically includes guide holes 11 and guide posts 8. The hollow pipe pile 4 has multiple guide holes 11 penetrating both sides of each loading port 10, with the axial direction of the guide holes completely aligned with the sliding direction of the push plate 5. On the side of the push plate 5 closest to the hollow pipe pile 4, several guide posts 8 matching the guide holes 11 are fixed. The guide posts can slide freely along the guide holes, preventing the push plate from swaying left and right when under force. The symmetrically arranged guide holes and guide posts on both sides form a stable "double-guide" structure, balancing the force on the push plate, preventing the push plate from tilting due to unilateral force, and ensuring efficient transmission of radial force to the outer soil.

[0050] A guide rail 6 distributed along the axial direction is installed inside the hollow pipe pile 4. Preferably, the guide rail 6 is an axial guide rail that is installed into the hollow pipe pile 4 later, or as shown in the figure, the guide rail 6 is formed inside the hollow pipe pile 4 at the same time as it is manufactured.

[0051] At least one active propulsion mechanism 12 is slidably mounted on the guide rail 6. This mechanism can move freely along the guide rail to adapt to the position requirements of loading ports at different heights. In this embodiment, the active propulsion mechanism 12 is a servo jack, which is precisely controlled by a hydraulic system and can provide real-time feedback on the thrust and extension, facilitating dynamic adjustments by construction personnel based on monitoring data. After the hydraulic rod (i.e., the jacking rod) of the servo jack passes through the loading port 10, it acts directly on the push plate 5, pushing the push plate radially outward to apply pressure to the outer soil, thereby counteracting the stress release caused by the excavation of the foundation pit and achieving active control over the deformation of the retaining structure.

[0052] In this embodiment, a first pad 9 is provided on the side of the push plate 5 near the hollow pipe pile 4, and the position of the pad coincides with the loading port 10 in the radial direction. When the push plate 5 is in contact with the outer wall of the hollow pipe pile 4, the first pad 9 extends into the loading port 10. The first pad has two main functions: first, when the push plate is not under force, the structure extending into the loading port temporarily fixes the push plate, preventing it from falling off or shifting during the driving and transportation of the pipe pile; second, as the direct point of action of the push rod, it can prevent the push rod from being under long-term force, which would cause the contact surface of the push plate to sink, thus ensuring the stability of force transmission. In addition, the thickness of the pad matches the width of the loading port, ensuring that it can be smoothly inserted without rubbing against the edge of the loading port when the push plate moves.

[0053] In this embodiment, several second pads 13 are fixed axially inside the hollow pipe pile 4. The position of each second pad corresponds to the corresponding loading port 10, and they are distributed at 180° opposite sides inside the hollow pipe pile (i.e., at both ends of the diameter of the pipe pile cross-section, corresponding to the loading port). The second pads are the reaction support points of the active propulsion mechanism: when the push rod of the active propulsion mechanism pushes the push plate outward, the mechanism itself will be subjected to a reaction force. This reaction force is transmitted to the hollow pipe pile through the second pads, and then dispersed by the pipe pile to the surrounding soil. The 180° opposite side distribution design ensures that the reaction force and the push force of the push plate are on the same straight line, avoiding additional bending moment caused by force deviation of the pipe pile, and ensuring the stability of the pipe pile structure. The second pads are usually fixed to the inner wall of the pipe pile by welding. Their size is determined by calculation based on the maximum thrust and must meet the compressive strength requirements.

[0054] In this embodiment, adjacent push plates 5 can be designed as a single, fixedly connected push plate (e.g., Figure 6 (As shown). This design is suitable for scenarios where overall deformation adjustment is required within a certain height range of a foundation pit. For example, when a soil layer is thick and the soil deformation is uniform, the entire push plate can provide a larger bearing area, allowing the adjustment force to be transmitted more evenly to the soil and avoiding excessive local stress that could lead to soil shear failure. The entire push plate can be connected by welding or high-strength bolts to ensure that each part of the push plate moves synchronously. Its length is determined according to the spacing and number of adjacent loading ports, typically covering 2-3 loading ports. Correspondingly, subsequent control of this entire push plate also requires the simultaneous operation of multiple active propulsion mechanisms 12 to synchronously push its displacement.

[0055] In this embodiment, each loading port 10 within the hollow pipe pile 4 is equipped with an active propulsion mechanism 12, and multiple active propulsion mechanisms are connected in series via steel strands 14. The advantages of the series design are: firstly, multiple propulsion mechanisms can be synchronously or individually controlled through the same control system, flexibly adjusting the thrust at different heights; secondly, the steel strands can connect the mechanisms into a whole, facilitating overall lowering or lifting within the pipe pile and simplifying the construction process.

[0056] The construction process of this invention is as follows:

[0057] S1. First, assemble the pusher plate and hollow pipe pile: Align the guide post 8 of each pusher plate 5 with the guide hole 11 of the hollow pipe pile 4 and insert it. Then push the pusher plate until it is tightly fitted against the outer wall of the pipe pile. At this time, the first pad 9 just extends into the loading port 10, forming a complete pile foundation assembly. Subsequently, according to the design drawings, around the building / tunnel to be protected, use a static pile driver or vibratory pile driver to drive the pile foundation to the design elevation at predetermined intervals. During the pile driving process, the verticality of the pile body needs to be monitored to avoid misalignment between the loading port and the pusher plate due to tilting.

[0058] S2. Connect several active propulsion mechanisms 12 (servo jacks) in series via steel strands 14, and adjust the relative height of each mechanism so that they correspond one-to-one with the height of the loading port 10 on the hollow pipe pile 4. Then, lower the series of active propulsion mechanisms as a whole to the designed elevation position inside the hollow pipe pile along the guide rail 6. During the lowering process, the height of the mechanisms needs to be calibrated using equipment such as a total station to ensure that the axis of the jacking rod of each mechanism coincides with the corresponding loading port and the center line of the first pad block, laying the foundation for the accuracy of subsequent force transmission.

[0059] S3. The first horizontal support 2 and the column pile 3 are constructed to form the initial horizontal constraint system. At this time, using the first support 2 and the soil in the passive zone of the foundation pit as reaction supports, before the foundation pit is excavated, the uppermost active propulsion mechanism 12 (jack) is activated, so that its jacking rod applies preload to the external push plate 5 through the loading port 10. The magnitude of the preload is determined based on the initial stress calculation of the soil before the foundation pit is excavated, with the purpose of compensating for part of the soil stress release space in advance and suppressing the initial deformation of the retaining structure.

[0060] S4. After initial preloading is completed, excavation begins layer by layer to the design elevation of each horizontal support. Before constructing each horizontal support, the corresponding active propulsion mechanism 12 must be activated to apply adjustment force to the outer soil through the push plate. This active adjustment force fills the deformation gap during support construction, preventing excessive deformation of the retaining structure due to incomplete support placement. The thrust is dynamically adjusted based on real-time monitoring of the retaining structure displacement data, typically using a "displacement control method," where the thrust is increased when the monitored displacement approaches the warning value.

[0061] S5. After the foundation pit is excavated to the bottom, the pre-applied axial force of each active propulsion mechanism 12 must remain unchanged until the basement structure is constructed to the ground. This is because before the basement structure has formed rigidity, the retaining structure still needs to rely on adjusting force to balance the soil pressure; after the basement floor slab, walls and other structures are completed, their own rigidity can replace the adjusting force, and only then can the load be gradually unloaded.

[0062] S6. After the basement structure construction is completed, the multiple active propulsion mechanisms 12 connected in series will be removed as a whole from the hollow pipe pile 4 via steel strands 14. After cleaning, they can be reused in other projects, reducing equipment costs. The removal process must be carried out slowly to avoid collisions between the mechanisms and the inner wall of the pipe pile or the guide rail.

[0063] The advantage of this embodiment is that deformation control of the retaining structure throughout its entire height and process can be achieved through multiple jacks connected in series. Regardless of the depth of the excavation, the horizontal support of the top excavated area can still maintain the pre-applied axial force through the corresponding jacks, ensuring that the deformation is always within a controllable range. Therefore, this solution is particularly suitable for deformation-sensitive scenarios, such as those with ancient buildings or subway tunnels around the excavation pit that require strict protection.

[0064] Example 2

[0065] This embodiment is designed for scenarios with lower construction requirements (such as shallow foundation pits and low sensitivity of the surrounding environment to deformation). To reduce equipment costs, only one active propulsion mechanism (jack) is used to achieve deformation adjustment. Figure 10 As shown, the specific steps are as follows:

[0066] S1. Similar to Example 1, first insert the guide post 8 of the push plate 5 into the guide hole 11 of the hollow pipe pile 4, so that the push plate fits against the outer wall of the pipe pile to form a complete pile foundation. Then, according to the design drawings, press the pile foundation into the design elevation at predetermined intervals around the area to be protected, ensuring that the verticality and spacing of the pile foundation meet the requirements.

[0067] S2. Suspend the single active propulsion mechanism 12 on the hook of the crane via steel strand 14. The length of the steel strand is preset according to the depth of the pipe pile. Then, slowly lower the active propulsion mechanism 12 into the hollow pipe pile 4 along the guide rail 6. Fine-tune the height of the mechanism using the crane to make it correspond to the height of the uppermost loading port 10 (e.g., ...). Figure 10 (As shown in a). During the lowering process, the position of the mechanism needs to be monitored through the observation hole at the top of the pipe pile to ensure that the axis of the jacking rod is aligned with the center line of the loading port.

[0068] S3. The first horizontal support 2 and the column pile 3 form the initial constraint. Using the first support 2 and the soil in the passive zone of the foundation pit as reaction supports, before the foundation pit is excavated, the active propulsion mechanism 12 is activated, causing its push rod to apply preload (such as...) to the external push plate 5 through the uppermost loading port 10. Figure 10 (As shown in b). The magnitude of the preload is determined based on the stress calculation of the shallow soil, with the aim of controlling the initial deformation at the top of the foundation pit.

[0069] S4. After the retaining structure stabilizes under preload, begin excavating the earth layer by layer to the design elevation of the next horizontal support. Before constructing each horizontal support, slowly lower the active propulsion mechanism 12 to the corresponding horizontal height of the loading port 10 using a crane (e.g., ...). Figure 10 (As shown in c), then restart the mechanism to apply adjustment force to the push plate. Since a single mechanism needs to move between different heights, the following precautions should be taken during operation: before lowering the mechanism, the push rod must be unloaded to avoid friction with the push plate or the inner wall of the pipe pile; after reaching the position, the alignment accuracy between the push rod and the loading port must be recalibrated.

[0070] S5. After the foundation pit is excavated to the bottom, adjust the active propulsion mechanism 12 to the height of the corresponding bottom loading port, keeping the pre-applied axial force unchanged, until the basement structure is constructed to the ground (e.g., Figure 10 (As shown in d). During this period, the thrust stability of the mechanism needs to be checked regularly to prevent thrust attenuation due to hydraulic system leaks.

[0071] S6. After the basement structure is completed, the jacking rods are unloaded, and the active propulsion mechanism 12 is removed from the hollow pipe pile by a crane. After cleaning, it is recycled and reused.

[0072] The advantages of this embodiment are low equipment cost (requiring only one active propulsion mechanism) and relatively simple operation, making it suitable for small to medium-sized foundation pit projects with low deformation control requirements. Its core lies in the "mobile reuse" of the mechanism to cover key adjustment heights at different construction stages, balancing cost and safety.

[0073] The preferred embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and the devices and structures not described in detail should be understood as being implemented in a conventional manner in the art. Any person skilled in the art can make many possible variations and modifications to the technical solutions of the present invention using the methods and techniques disclosed above, or modify them into equivalent embodiments with equivalent changes, without departing from the scope of the present invention. This does not affect the essential content of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the present invention's technical solutions still fall within the protection scope of the present invention.

Claims

1. A deformation-actively adjustable steel pipe pile support structure, comprising hollow pipe piles, characterized in that, Several loading ports are spaced apart along the axial direction on the side wall of the hollow pipe pile. A radially sliding push plate is configured on the outer side wall of the hollow pipe pile corresponding to each loading port. A radial guide mechanism is connected between the push plate and the hollow pipe pile. Axially distributed guide rails are installed inside the hollow pipe pile, and at least one active propulsion mechanism is slidably installed on the guide rails. The active propulsion mechanism is equipped with a push rod, which pushes the push plate outward through the loading port to control the deformation of the retaining structure.

2. The deformation-actively-adjustable steel pipe pile support structure as described in claim 1, characterized in that, Hollow pipe piles are circular, rectangular, or square steel pipe piles; The side of the push plate closest to the hollow pipe pile is in contact with the outer wall of the hollow pipe pile.

3. The deformation-actively-adjustable steel pipe pile support structure as described in claim 1, characterized in that, The radial guiding mechanism includes a guide hole and a guide post; Hollow pipe piles have guide holes on both sides of each loading port that are aligned with the sliding direction of the push plate. A guide column that slides through the guide hole is fixed on the side of the push plate closest to the hollow pipe pile.

4. The deformation-actively-adjustable steel pipe pile support structure as described in claim 2, characterized in that, The push plate is provided with a first pad that coincides with the loading port in the radial direction on the side near the hollow pipe pile; When the push plate is in contact with the outer wall of the hollow pipe pile, the first pad block extends into the loading port.

5. The deformation-actively-adjustable steel pipe pile support structure as described in claim 1, characterized in that, Several second pads are fixed axially inside the hollow pipe pile. Each second pad corresponds to a loading port and is distributed 180° opposite to each other inside the hollow pipe pile.

6. The deformation-actively-adjustable steel pipe pile support structure as described in claim 1, characterized in that, Multiple adjacent push plates are fixedly connected as a single push plate.

7. The deformation-actively-adjustable steel pipe pile support structure as described in claim 1, characterized in that, The active propulsion mechanism is a servo jack.

8. The deformation-actively-adjustable steel pipe pile support structure as described in claim 7, characterized in that, An active propulsion mechanism is installed in each loading port inside the hollow pipe pile, and multiple active propulsion mechanisms are connected in series by steel strands.

9. The deformation-actively-adjustable steel pipe pile support structure as described in claim 7, characterized in that, There is only one active propulsion mechanism inside the hollow pipe pile, which is connected to the lifting drive mechanism.

10. A construction method for a deformation-actively adjustable steel pipe pile support structure, characterized in that, Includes the following steps: S1. Hollow pipe piles are driven to the design depth. Several loading ports are spaced apart along the axial direction on the side wall of the same side of the hollow pipe pile. A radially sliding push plate is configured on the outer side wall of the hollow pipe pile corresponding to each loading port. A radial guide mechanism is connected between the push plate and the hollow pipe pile. An axially distributed guide rail is installed inside the hollow pipe pile. At least one active propulsion mechanism is slidably installed on the guide rail. The active propulsion mechanism is equipped with a push rod. The push rod pushes the push plate outward through the loading port. S2. Before the foundation pit is excavated, at least one active propulsion mechanism is activated to apply horizontal preload to the push plate at the corresponding height through the push rod, so as to compensate for the release of soil excavation stress in advance. S3. As the foundation pit is excavated in layers, the pre-applied axial force of the active propulsion mechanism is adjusted in real time to control the deformation of the retaining structure. S4. After the basement structure has achieved rigidity, the active propulsion mechanism is gradually unloaded and removed from the hollow pipe pile.

11. A construction method as described in claim 10, characterized in that, The active propulsion mechanism is a servo jack; In steps S2-S3, a servo jack is installed in each loading port inside the hollow pipe pile, and multiple servo jacks are connected in series by steel strands; as the foundation pit is excavated in layers, the servo jacks at the corresponding heights are controlled synchronously or individually to adjust the pre-applied axial force in real time.

12. The construction method as described in claim 10, characterized in that, There is only one active propulsion mechanism inside the hollow pipe pile, and the active propulsion mechanism is connected to the lifting drive mechanism; In steps S2-S3, before the foundation pit is excavated, the active propulsion mechanism is lowered to the height corresponding to the uppermost loading port and pre-pressure is applied. As each layer of earthwork is excavated and before the construction of the next horizontal support is completed, the active propulsion mechanism is moved to the height of the corresponding loading port through the lifting drive mechanism and the adjustment force is reapplied until the foundation pit is excavated to the bottom.

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