A pile body anti-side shift structure for soft stratum construction

Abstract

The utility model provides a kind of pile body anti-side shift structure for soft stratum construction, including pile basic body, annular base and multiple side positioning mechanisms;Annular base is set in the middle part of pile basic body, and multiple side positioning mechanisms are circumferentially evenly arranged and set in annular base, and side positioning mechanism is used to realize the side support to pile basic body;Side positioning mechanism includes lateral support plate, fixed base, magnetic attraction fixed component and two sets of symmetrically arranged elastic strut mechanism.The pile body anti-side shift structure for soft stratum construction of the utility model solves the problem that the pile sinking process in the related art causes strong soil squeezing effect in soft soil layer, leading to pile body deviation during subsequent soil excavation due to lateral earth pressure pushing, ultimately causing group pile bearing capacity to decline and overall deviation problem.

Description

Technical Field

[0001] This utility model belongs to the field of pipe pile technology, and in particular relates to a pile body anti-lateral displacement structure for construction in soft strata. Background Technology

[0002] Prestressed concrete pipe piles are factory-prefabricated concrete piles manufactured using centrifugal molding and high-temperature, high-pressure curing. They feature high single-pile bearing capacity, fast construction speed, and good compressive and crack resistance. The concrete strength grade of the pile body is typically C60-C80, making them suitable for engineering scenarios requiring settlement control, such as deep soft soil and embankment subgrades. When constructed in soft soil strata (such as silt and silty clay), the pipe piles are prone to lateral displacement, heave, or tilting due to the soil's high sensitivity, low shear strength, and high pore water pressure. For example, the strength of disturbed soft soil decreases significantly, leading to plastic flow in the surrounding soil and causing horizontal displacement of the pile. The pile driving process in related technologies induces a strong soil squeezing effect in soft soil layers, resulting in a surge in pore water pressure and damage to the surrounding soil structure, causing a decrease in soil strength and the uplift of adjacent piles. Simultaneously, the pipe piles themselves have insufficient bending resistance, making them prone to displacement under lateral earth pressure during subsequent excavation, ultimately leading to a decrease in the bearing capacity of the pile group and overall misalignment. Summary of the Invention

[0003] In view of this, the present invention aims to at least partially solve one of the related technical problems.

[0004] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0005] A pile anti-lateral displacement structure for construction in soft strata includes a pile body, an annular base, and multiple side positioning mechanisms;

[0006] The annular base is disposed in the middle of the pile foundation body, and a plurality of the side positioning mechanisms are evenly arranged in a circle on the annular base. The side positioning mechanisms are used to provide side support for the pile foundation body.

[0007] The side positioning mechanism includes:

[0008] Lateral support plate, the inner surface of which faces the axis of the pile foundation;

[0009] A fixed base is rigidly connected to the outer wall of an annular base;

[0010] The magnetic fixing assembly can be releasably locked into the retracted position of the lateral support plate;

[0011] Two sets of symmetrically arranged elastic strut mechanisms are respectively installed at the upper and lower ends of the fixed base. One end of the elastic strut mechanism is connected to the fixed base, and the other end of the elastic strut mechanism is connected to the lateral support plate.

[0012] The magnetic fixing component is located between the two elastic strut mechanisms. One end of the magnetic fixing component is connected to the fixed base, and the other end of the magnetic fixing component is connected to the lateral support plate.

[0013] When the magnetic fixing assembly is released, the preloaded spring of the elastic strut mechanism drives the strut assembly of the elastic strut mechanism to push the lateral support plate radially outward against the formation.

[0014] Furthermore, the elastic strut mechanism includes a guide groove, a slide rod, a preload spring, and a strut assembly. The guide groove is disposed on the inner wall of the lateral support plate, the slide rod is disposed in the middle of the guide groove, one end of the strut assembly is slidably engaged with the slide rod, and the other end of the strut assembly is connected to the fixed base through a hinged support. The preload spring is sleeved on the slide rod and is used to press the end of the strut assembly.

[0015] Furthermore, the strut assembly includes a support rod and a slider, the slider being slidably engaged with the slide rod, and the support rod being hinged to the slider via a rotating rod.

[0016] Furthermore, the magnetic fixing assembly includes a magnetic block, a fixing block, a guide rod, a guide sleeve, and an electromagnet. The guide sleeve is disposed in the middle of the fixing base. The guide sleeve is slidably engaged with the guide rod. The end of the guide rod away from the guide sleeve is connected to the lateral support plate through the fixing block. The magnetic block is disposed on the fixing block, and the electromagnet is disposed at the end of the guide sleeve away from the fixing base.

[0017] Furthermore, it includes an annular retaining ring, which is integrally connected to the outer wall of the pile base and located below the annular base;

[0018] When the lateral support plate is in the contracted state locked by the magnetic fixing assembly, the radial thickness of the annular retaining ring is greater than the maximum assembly gap from the outer surface of the annular base to the inner surface of the lateral support plate, and the bottom of its outer wall is a conical structure.

[0019] Furthermore, it also includes multiple ribs, which are evenly arranged circumferentially on the upper part of the pile body, and the cross-section of the ribs is T-shaped.

[0020] Furthermore, the number of the side positioning mechanisms is three.

[0021] Compared with existing technologies, the pile anti-lateral displacement structure for soft strata construction described in this utility model has the following advantages:

[0022] 1. During the pile driving stage, the side positioning mechanism uses magnetic fixing components to keep the lateral support plate in a contracted state that is nearly flush with the outer wall of the pile, thus not significantly increasing the protrusion and resistance when penetrating soft strata; the annular base and the fixed base form a rigid bearing path, so that the impact and vibration during the pile driving process will not be transmitted to the support plate for malfunction; the annular retaining ring located below it, due to its radial thickness being greater than the assembly gap and the tapered structure set on the outer edge, can provide circumferential limiting and guiding protection against mud scouring and local disturbances; when the pile is driven into place, the electromagnet can be released and locked by simply de-energizing or reversing the excitation, and the preloaded spring, through the cooperation of the elastic support rod and the guide groove-slide rod-slider, will push the support plate outward to the stratum stably and synchronously; the three sets of circumferentially distributed mechanisms can thus form a balanced three-point support at the moment of release.

[0023] 2. When the lateral support plate is pushed outward to the stratum, the pile-soil interaction changes from simple interfacial friction to surface pressure contact and shear interlocking with a certain area, thus achieving higher initial lateral stiffness in the small displacement stage; the annular base and fixed base provide stable force flow transmission, allowing the reaction force of the support plate to be efficiently transmitted to the pile body without creating local weak areas; two sets of symmetrically arranged elastic strut mechanisms form redundant and self-correcting kinematic geometry at each support position, reducing the risk of eccentric displacement caused by unilateral weakness; the T-shaped rib plate set at the top provides an increase in section modulus along the pile axis, further suppressing the bending deformation of the pile body under lateral load; the three circumferentially symmetrical supports, combined with the stiffness enhancement of the upper rib plate, ultimately effectively reduce the lateral displacement and tilt of a single pile in soft strata, making it easier to meet common deformation limit requirements. Attached Figure Description

[0024] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0025] Figure 1 This is a schematic diagram of a pile anti-lateral displacement structure for construction in soft strata, as described in an embodiment of this utility model.

[0026] Figure 2 This is a schematic diagram of the side positioning mechanism described in an embodiment of the present utility model;

[0027] Figure 3 This is a schematic diagram of the strut assembly and magnetic fixing assembly described in an embodiment of the present utility model;

[0028] Figure 4 This is a schematic diagram of the rib plate described in an embodiment of the present utility model.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100. Pile base; 110. Fixing ring; 210. Annular base; 310. Fixing base; 320. Support rod assembly; 330. Magnetic fixing assembly; 331. Guide sleeve; 332. Electromagnet; 333. Guide rod; 400. Annular retaining ring; 500. Rib plate; 610. Sliding rod; 620. Preload spring; 630. Sliding block; 700. Side support plate. Detailed Implementation

[0031] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0032] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0033] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0034] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] When precast piles are driven and excavated in soft soil strata (such as silt, silty clay, and high-void-ratio saturated soft clay), problems such as lateral displacement, heave, or tilting of the piles often occur due to the high sensitivity of the soil, low shear strength, and accumulation of excess pore water pressure. Furthermore, when there is adjacent excavation or eccentric load on the superstructure during the construction phase, the bending and lateral deformation of the upper pile segment are particularly sensitive, which significantly increases the difficulty of controlling the overall bearing capacity and relative displacement of the pile group. To address this, this embodiment proposes a pile anti-lateral displacement structure for construction in soft soil strata. Without relying on grouting or large-scale site reinforcement, it achieves a significant improvement in lateral stiffness and initial anti-sliding bearing capacity through mechanical radial lateral support in the middle of the pile and structural reinforcement of the upper pile segment, thereby suppressing the accumulation of lateral displacement during the excavation impact period and the early stage of operation and reducing the risk of adjacent piles floating.

[0036] The anti-lateral displacement structure of the pile body in this embodiment includes a pile body 100, an annular base 210, and multiple side positioning mechanisms. Preferably, there are three side positioning mechanisms, which are evenly arranged on the outer periphery of the annular base 210 at 120° circumferential intervals. The annular base 210 is integrally fixed in the middle region of the pile body 100, preferably located in the bending sensitive zone 3 to 8m below the bottom of the pile cap, so as to form effective lateral support at the location where the pile-soil interaction is strongest. Each side positioning mechanism is used to push its lateral support plate radially outward to the stratum in the released state to provide local surface pressure and shear interlocking, while in the contracted state it remains basically flush with the outer wall of the pile to avoid significantly increasing the pile driving resistance and construction risk.

[0037] Each side positioning mechanism includes a lateral support plate facing the axis of the pile body 100, a fixed base 310 rigidly connected to the outer wall of the annular base 210, two sets of elastic strut mechanisms located at the upper and lower ends and symmetrically arranged, and a magnetic fixing assembly 330 arranged between the two sets of elastic strut mechanisms and capable of releasing and locking the lateral support plate in the retracted position; wherein, the inner surface of the lateral support plate is provided with a guide groove extending parallel to the pile axis, and a sliding rod 610 is provided in the guide groove and forms a sliding fit with the lateral support plate, and one end of the elastic strut mechanism is connected to the fixed base 310. The side support plate is hinged or rigidly connected, with the other end slidingly engaged with the slide rod 610—a lateral support plate assembly. A preload spring 620 is coaxially sleeved on the slide rod 610 to apply preload after assembly. When the magnetic fixing assembly 330 is released, the preload spring 620 pushes the lateral support plate radially outward to the stratum with a limited stroke and controlled speed through the strut assembly 320 to form a stable support. To improve soil penetration guidance and avoid local soil snagging, the outer edge of the lateral support plate is preferably chamfered or has a soil penetration guide chamfer of 5° to 15°, and its outer surface can be coated with a wear-resistant and anti-corrosion coating to improve long-term service reliability.

[0038] The strut assembly 320 consists of a slider 630 that slides with the slide rod 610 and a support rod. The support rod and the slider 630 are hinged by a rotating rod to allow the lateral support plate to self-adjust at a small angle during the radial outward push. The geometric constraint and force transmission of the component movement are realized through the hinged support on the fixed base 310. In order to control the limit position of the entire outward push stroke and avoid overtravel due to local softness of the stratum, a stroke stop can be set on the fixed base 310, and an energy absorption pad is set at the end of the guide groove to attenuate the end impact. The fit tolerance between the slide rod 610 and the guide groove is preferably 0.05~0.20mm to balance smooth movement and lateral guiding stiffness.

[0039] The magnetic fixing assembly 330 consists of a magnetic block, a fixing block, a guide rod 333, a guide sleeve 331, and an electromagnet 332. The guide sleeve 331 is located in the middle of the fixing base 310 and forms a low-friction sliding fit with the guide rod 333. The end of the guide rod 333 away from the guide sleeve 331 is reliably connected to the lateral support plate via the fixing block. The magnetic block is mounted on the fixing block and, in its retracted state, is attracted to the electromagnet 332 to lock and retain the lateral support plate. The electromagnet 332 is preferably located at the end of the guide sleeve 331 away from the fixing base 310 and is connected via an electromagnet pre-embedded in the pile. The cable is electrically connected to the quick-connect interface at the top of the pile. To meet the requirements of convenient construction and reliable release in the event of power failure, the electromagnet 332 provides attraction and retention when energized and releases attraction when power is cut off or reverse excitation is applied. It can also be equipped with a one-time power supply inside the pile or a temporary external power supply to implement centralized release after pile driving is completed, thereby ensuring that deployment can be completed without maintaining power supply on the ground for a long time. To improve the adsorption stability and resistance to mud intrusion, the magnetic block and the electromagnet adsorption surface are preferably covered with stainless steel and equipped with O-ring seals. The exposed gap between the guide sleeve 331 and the guide rod 333 is equipped with anti-mud brush rings to reduce particle intrusion.

[0040] The annular retaining ring 400 is integrally connected to the outer wall of the pile base 100 and is located below the annular base 210. The annular retaining ring 400 is used to provide circumferential restraint and protection during pile driving when the side positioning mechanism is in the retracted state. The radial thickness of the annular retaining ring 400 is designed to be greater than the maximum assembly gap from the outer surface of the annular base 210 to the inner surface of the side support plate, so as to avoid the side support plate from generating undesirable radial outward jump under the impact of pile driving and lateral disturbance. The bottom of the outer wall of the annular retaining ring 400 is provided with a tapered chamfer to reduce local resistance and circumferential mud disturbance when penetrating the soil. The preferred cone angle is 30° to 45° and a wear-resistant layer is provided on the outer edge to improve wear resistance.

[0041] To enhance the bending stiffness of the upper pile segment and improve the overall deformation performance under lateral loads, multiple ribs 500 can be provided on the upper part of the pile body 100. The multiple ribs 500 are evenly arranged on the upper part of the pile body and form a composite section with the pile body. The cross-sectional shape of the rib 500 is T-shaped and its web extends along the pile axis. The flanges are reliably connected to the outer wall of the pile by shear studs or anchors. The preferred material for the ribs is Q355 grade steel plate with hot-dip galvanizing or heavy anti-corrosion coating. Circular sleeves can be set between the ribs to suppress local ellipticization and enhance the cross-sectional coordination between the flange and the pile wall. To ensure overall assembly accuracy and manufacturing consistency, the annular base 210, fixed base 310, guide sleeve 331, and ribs 500 are all cast together with the pile body 100 in the prefabrication plant or embedded afterward. Non-destructive testing is carried out on key welds and water pressure resistance and insulation tests are performed on electromagnetic components.

[0042] In summary, the three sets of side positioning mechanisms are circumferentially distributed at 120° in the middle of the pile body 100 through the annular base 210. During the pile driving stage, the magnetic fixing component 330 provides reliable shrinkage locking, and the annular retaining ring 400 achieves external protection and circumferential limitation. After the pile driving is completed and the design elevation is reached, the electromagnet 332 is de-energized or reverse-excited to release the preload spring 620, which is guided by the strut assembly 320 and the slide rod 610-lateral support plate to push the lateral support plate radially outward synchronously and smoothly to the surrounding soil. This forms a three-point symmetrical surface contact support and shear interlocking zone at the pile-soil interface. Combined with the bending stiffness increased by the upper T-shaped rib plate 500, the lateral displacement of a single pile in a soft soil environment is effectively suppressed.

[0043] As a preferred embodiment, the top of the pile body 100 is provided with an integral fixing ring 110 coaxial with it. The fixing ring 110 is preferably a steel ring component, which is integrally cast with the pile top concrete during the prefabrication stage through circumferential shear nails and vertical anchor bars. Its outer diameter is flush with or slightly concave with the outer wall of the pile to ensure fitting with the pile cap and disassembly and assembly of the formwork. In addition to bearing the load transfer and shear and torsional positioning between the pile top and the pile cap (or cap beam), the fixing ring 110 also serves as a sealing and process interface platform during the construction period. Several grouting holes are evenly arranged along the circumference on its upper end face and can be equipped with internal threaded interfaces and one-way check valves (with dust caps and O-ring seals if necessary) so that low-pressure or medium-pressure grouting / pressurization processes can be implemented in the key areas of the pile top after the pile is driven into place and the side positioning mechanism is released. On the one hand, it can supplement the steel lining-grouting-concrete composite area of ​​the upper stiffening section with micro-expansion grout. It fills any possible micro-voids, removes residual gas and free water, and improves bonding and early stiffness. On the other hand, before and after the foundation is poured, grouting can be performed through the grouting holes of the fixing ring 110 to the pile top-foundation contact surface or the reserved cushion layer, forming a dense interface layer and a waterproof sealing strip, thereby reducing the risk of pile top "void" and secondary settlement and increasing the effective working area of ​​the shear key. In addition, the grouting holes can also be temporarily used as vacuum and drying channels for cable ducts such as electromagnet 332 or pressure monitoring and recharge ports during maintenance. During construction, the procedure is carried out according to "pressing in until the grout outlet is stable or the pressure is stable - maintaining pressure - sealing". Finally, the grouting holes are sealed with threaded metal plugs and sealant and reliably overlapped with the foundation steel mesh, so that the fixing ring 110 not only completes the structural force transmission function, but also provides a standardized and repeatable process interface, ensuring the structural reliability and durability of the pile top area.

[0044] How this example works

[0045] Step 1: After the pile body 100, which is equipped with an annular base 210, three sets of side positioning mechanisms, annular retaining ring 400 and upper rib plate 500, is completed in the prefabrication plant and inspected before leaving the factory, it is transported to the site. The pile is driven by static pressure or controlled energy level hammering. During this period, the lateral support plate is kept contracted and nearly flush with the outer wall of the pile by the attraction of the magnetic fixing component 330. The radial thickness and conical outer edge of the annular retaining ring 400 are used to achieve circumferential protection and guidance for the positioning mechanism until the pile body reaches the designed bearing layer and the penetration control is completed.

[0046] Step 2: After the pile body is in place and the necessary depressurization and rest are completed, the electromagnet 332 is de-energized or reverse-excited as needed through the quick interface at the top of the pile to release the magnetic block and the electromagnet from adsorption. This allows the two sets of symmetrically arranged elastic strut mechanisms to drive the strut assembly 320 to push the lateral support plate outward synchronously along the path of the guide groove-slide rod 610 under the elastic force of the preload spring 620, until the lateral support plate forms a stable contact with the surrounding strata and reaches the position limited by the stroke stop. This establishes reliable radial support and shear engagement at three circumferential positions in the middle of the pile body. After that, the conventional connection with the pile cap or tie beam structure is completed, and the subsequent excavation and superstructure construction stage can begin.

[0047] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A pile anti-lateral displacement structure for construction in soft strata, characterized in that: It includes a pile base (100), an annular base (210), and multiple side positioning mechanisms; The annular base (210) is disposed in the middle of the pile foundation body (100), and a plurality of the side positioning mechanisms are evenly arranged in a circle on the annular base (210). The side positioning mechanisms are used to provide side support for the pile foundation body (100). The side positioning mechanism includes: Lateral support plate, the inner surface of which faces the axis of the pile body (100); A fixed base (310) is rigidly connected to the outer wall of an annular base (210); The magnetic fixing assembly (330) can be releasably locked in the retracted position for the lateral support plate; Two sets of symmetrically arranged elastic strut mechanisms are respectively set at the upper and lower ends of the fixed base (310). One end of the elastic strut mechanism is connected to the fixed base (310), and the other end of the elastic strut mechanism is connected to the lateral support plate. The magnetic fixing component (330) is located between the two elastic strut mechanisms. One end of the magnetic fixing component (330) is connected to the fixed base (310), and the other end of the magnetic fixing component (330) is connected to the lateral support plate. When the magnetic fixing assembly (330) is released, the preload spring (620) of the elastic strut mechanism drives the strut assembly (320) of the elastic strut mechanism to push the lateral support plate radially outward against the formation.

2. The pile anti-lateral displacement structure for construction in soft strata according to claim 1, characterized in that: The elastic strut mechanism includes a guide groove, a slide rod (610), a preload spring (620), and a strut assembly (320). The guide groove is disposed on the inner wall of the lateral support plate. The slide rod (610) is disposed in the middle of the guide groove. One end of the strut assembly (320) is slidably engaged with the slide rod (610). The other end of the strut assembly (320) is connected to the fixed base (310) through a hinged support. The preload spring (620) is sleeved on the slide rod (610) and is used to press the end of the strut assembly (320).

3. A pile anti-lateral displacement structure for construction in soft strata according to claim 2, characterized in that: The strut assembly (320) includes a support rod and a slider (630). The slider (630) is slidably engaged with the slide rod (610). The support rod and the slider (630) are hinged together by a rotating rod.

4. A pile anti-lateral displacement structure for construction in soft strata according to any one of claims 1-3, characterized in that: The magnetic attraction fixing assembly (330) includes a magnetic attraction block, a fixing block, a guide rod (333), a guide sleeve (331), and an electromagnet (332). The guide sleeve (331) is disposed in the middle of the fixing base (310). The guide sleeve (331) is slidably engaged with the guide rod (333). The end of the guide rod (333) away from the guide sleeve (331) is connected to the lateral support plate through the fixing block. The magnetic attraction block is disposed on the fixing block. The electromagnet (332) is disposed at the end of the guide sleeve (331) away from the fixing base (310).

5. A pile anti-lateral displacement structure for construction in soft strata according to claim 4, characterized in that: Includes an annular retaining ring (400), which is integrally connected to the outer wall of the pile base body (100) and located below the annular base (210); When the lateral support plate is in the contracted state locked by the magnetic fixing assembly (330), the radial thickness of the annular retaining ring (400) is greater than the maximum assembly gap from the outer surface of the annular base (210) to the inner surface of the lateral support plate, and the bottom of its outer wall is a conical structure.

6. A pile anti-lateral displacement structure for construction in soft strata according to claim 4, characterized in that: It also includes multiple ribs (500), which are evenly arranged circumferentially on the upper part of the pile body (100), and the cross-section of the ribs (500) is T-shaped.

7. A pile anti-lateral displacement structure for construction in soft strata according to claim 4, characterized in that: The number of side positioning mechanisms is 3.

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