Novel anti-slide pile and construction method thereof

Abstract

The invention provides a novel anti-slide pile and a construction method thereof. The novel anti-slide pile comprises a plurality of anti-slide piles with I-shaped sections and prefabricated breast boards fixed between every two adjacent anti-slide piles, each anti-slide pile comprises a prefabricated anti-slide pile buried section and an anti-slide pile cantilever section, and the anti-slide pile buried sections and the anti-slide pile cantilever sections are connected through transverse wet joints. The prefabricated breast boards are mounted between the two adjacent slide-resistant pile cantilever sections; a plurality of grout outlets with different heights are formed in the surface of the anti-slide pile with the I-shaped section; the construction method of the novel anti-slide pile comprises the steps that all the components are prefabricated, then holes are formed in the field, the anti-slide pile with the I-shaped section is installed, the soil retaining plate is prefabricated, finally, grouting is conducted on the anti-slide pile with the I-shaped section, and grout flows out of the anti-slide pile with the I-shaped section and enters a surrounding soil layer to reinforce the surrounding soil body. According to the novel anti-slide pile, the using amount of concrete and steel bars is smaller; according to the construction method, factory prefabrication and on-site assembly are achieved, and the on-site construction speed and quality are improved.

Description

Technical Field

[0001] This application relates to the field of building engineering technology, and in particular to a novel anti-slide pile and its construction method. Background Technology

[0002] Anti-slide piles, as a highly efficient retaining structure, play a crucial role in slope stabilization, roadbed reinforcement, and tunnel support projects. Based on their structural characteristics of penetrating the sliding surface and anchoring to the underlying stable strata, anti-slide piles, under the action of landslide thrust or lateral earth pressure, transfer the load from the unstable upper soil to the deep stable strata through coordinated deformation with the surrounding rock and soil. The pile-soil interaction generates resistance to balance the external load, thereby inhibiting further soil slippage and significantly improving overall stability. Compared with traditional retaining structures, anti-slide piles have significant advantages such as strong spatial adaptability and minimal construction disturbance, making them particularly suitable for engineering scenarios involving complex terrain, deep slippage, or limited space.

[0003] Structurally, anti-slide piles are mainly constructed using reinforced concrete, steel, or composite materials (such as FRP-concrete composite piles), with square and round cross-sections being the most common. Square piles, due to their excellent bending resistance and significant soil arching effect, exhibit outstanding anti-slide capabilities. However, the difficulty in drilling square piles presents challenges such as high construction difficulty and poor economic efficiency. While round piles offer convenient construction and high cost-effectiveness, their bending stiffness is generally lower than that of square piles with the same material usage. Especially when facing large-scale landslide thrust with a clearly defined main sliding direction, it is often necessary to increase the diameter or configure a higher reinforcement ratio to meet the load-bearing requirements, leading to material waste and reduced economic efficiency. Furthermore, the contact interface between round piles and the soil is relatively smooth, resulting in a relatively weak soil arching effect. The stability of the soil between the piles relies on additional auxiliary measures such as baffles or shotcrete anchors.

[0004] Therefore, there is a need to provide an improved technical solution that addresses the shortcomings of the existing technology. Summary of the Invention

[0005] The purpose of this application is to provide a new type of anti-slide pile and its construction method to solve or alleviate the problems existing in the prior art.

[0006] To achieve the above objectives, this application provides the following technical solution: A novel anti-slide pile includes several I-shaped cross-section anti-slide piles and a precast retaining plate fixed between two adjacent anti-slide piles. Each anti-slide pile includes an embedded section and a cantilever section. The embedded section, cantilever section, and precast retaining plate are all precast reinforced concrete components. The embedded section and cantilever section are connected by a transverse wet joint. The precast retaining plate is installed between two adjacent cantilever sections. Each I-shaped cross-section anti-slide pile includes a back slope flange, an up slope flange, and a web vertically fixed between them. Prestressed steel strands are installed within the web of the I-shaped cross-section anti-slide pile. Grouting conduits are installed within the up slope flange and back slope flange of the I-shaped cross-section anti-slide pile. The grouting conduits extend to the surface of the I-shaped cross-section anti-slide pile to form several grout outlets of different heights.

[0007] In one embodiment, the two end faces of the precast retaining plate are connected to two adjacent anti-slide pile cantilever sections via longitudinal wet joints; in another embodiment, the precast retaining plate is inserted between two adjacent anti-slide pile cantilever sections.

[0008] Furthermore, the grouting conduit includes a soil-facing wing plate disposed on the I-shaped section anti-slide pile and a plurality of grouting branch pipes distributed in the soil-facing wing plate in the rock height direction. The grouting branch pipes are connected to the surface of the I-shaped section anti-slide pile and form a plurality of grout outlets on its surface.

[0009] Furthermore, at least two grouting branch pipes are installed in the soil-entry section of the anti-slide pile, and at least one grouting branch pipe is installed in the cantilever section of the anti-slide pile; each grouting branch pipe forms several grout outlets on the side of the I-shaped cross-section anti-slide pile in contact with the soil.

[0010] Furthermore, a first extension steel bar is reserved at the upper end of the anti-slide pile's embedded section, a second extension steel bar is reserved at the lower end of the anti-slide pile's cantilever section, a third extension steel bar is reserved on the side of the anti-slide pile's cantilever section facing the precast retaining plate, and a fourth extension steel bar is reserved on both sides of the precast retaining plate; the first extension steel bar is fixedly connected to the second extension steel bar, and the third extension steel bar is fixedly connected to the fourth extension steel bar.

[0011] This invention also proposes a construction method for the aforementioned novel anti-slide pile, comprising the following steps: Step P1: Prefabricate the anti-slide pile drive section, the anti-slide pile cantilever section, and the prefabricated retaining plate in the factory. The anti-slide pile drive section is pre-embedded with grouting pipes and tensioned prestressed steel strands. The lower end of the prestressed steel strands is anchored inside the anti-slide pile drive section, and the upper end is anchored to the outside of the anti-slide pile drive section through connectors for subsequent extension. The anti-slide pile cantilever section is pre-embedded with grouting pipes and prestressed pipes. Step P2: Drill holes on site according to the design location; Step P3: On-site installation of I-section anti-slide piles; First, place the anti-slide pile drive section into the pre-dug hole, adjust the verticality of the drive section, and then backfill and compact the soil in layers around the drive section until it reaches the original ground level; Place several pads on the top surface of the drive section and place the cantilever section of the anti-slide pile on the pads; Insert the steel strands through the lower end of the prestressed duct of the cantilever section, and fix the lower part of the steel strands to the connector, connecting the grouting pipe of the drive section and the grouting pipe of the cantilever section through the central pipe; Then, install templates around the interface of the drive section and the cantilever section, and pour concrete for the transverse wet joint; After the concrete strength of the wet joint reaches the design requirements, tension the prestressed steel strands of the cantilever section and grout. Step P4: Install the precast retaining plate between the two I-section anti-slide piles; Step P5: Inject grout into the grouting pipe. The grout flows out of the I-shaped anti-slide pile and enters the surrounding soil layer to reinforce the surrounding soil.

[0012] Furthermore, in step P2, the hole depth is the same as the longitudinal length of the anti-slide pile's entry section; the hole diameter is 200-500 mm larger than the circumscribed circle diameter of the I-shaped anti-slide pile.

[0013] Furthermore, in step P5, a grouting head that can be inserted into the grouting conduit is used for backward grouting; first, grouting is performed at the lowest grout outlet position, and before the grout initially sets, the grouting head is moved up to the corresponding grout outlet position of the previous layer and grouting is performed, and the entire grouting process is completed in this cycle; the thickness of the soil layer above the uppermost grout outlet position should be greater than 2m.

[0014] Furthermore, an air bladder is fixed to the outer periphery of the grouting head. During grouting, the air bladder is inflated so that it adheres tightly to the inner wall of the grouting conduit to form a seal; when the grouting head is moved upward, the air bladder is deflated.

[0015] Furthermore, in step P1, anchor holes are pre-reserved on the wing plate of the anti-slide pile cantilever section during prefabrication; and prestressed steel strands in the anti-slide pile soil entry section and prestressed ducts in the anti-slide pile cantilever section are arranged according to the anchor hole positions. In step P5, after the transverse wet joint has initially set, the hole is drilled into the stable stratum along the designed inclination angle and depth. Then, prestressed anchor rods are inserted into the anchor rod holes and tensioned, locked, and grouted for anchoring. Finally, the soil around the pile is reinforced by grouting through the grouting pipe.

[0016] The technical solution of this application has the following beneficial effects: The novel anti-slide pile of this invention requires less concrete than the commonly used rectangular or circular cross-section anti-slide pile under the same anti-slide capacity requirements, significantly reducing engineering costs; the prestressed steel strands inside the pile can enhance bending and shear resistance, further reducing the amount of steel reinforcement and concrete used.

[0017] The novel anti-slide pile of this invention reduces material usage and can be constructed using a factory prefabrication and on-site assembly method, which greatly improves construction speed. The prefabrication process ensures stable pile quality, reduces variability in on-site pouring, and improves overall project quality.

[0018] The construction method of this invention uses wet joints for on-site splicing, reducing the difficulty of transporting and hoisting individual components. The transverse wet joints not only ensure the continuity and overall rigidity of the pile structure, but also effectively transfer shear force and bending moment through the tight bond between cast-in-place concrete and pre-reserved reinforcing steel, avoiding the formation of weak interfaces. The construction method of this invention allows for rapid on-site installation, reduces soil exposure time, lowers the risk of slope instability, and improves construction safety. The I-shaped cross-section anti-slide pile is equipped with grouting holes, which can be used to reinforce the soil around the pile, further improving its anti-slide capacity and enhancing its overall stability. The two sections of prestressed steel strands are reliably connected by connectors and constructed using the post-tensioning method, ensuring continuous transmission of prestress throughout the entire pile. The prestressed steel strands can be flexibly arranged according to site requirements. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. Wherein: Figure 1 This is a structural schematic diagram of the novel anti-slide pile according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the anti-slide pile insertion section according to an embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the structure of the cantilever section of the anti-slide pile according to an embodiment of the present invention.

[0022] Figure 4 This is a side view of the cantilever section of the anti-slide pile according to an embodiment of the present invention.

[0023] Figure 5 This is a side view of the anti-slide pile insertion section according to an embodiment of the present invention.

[0024] Figure 6 This is a schematic diagram of the arrangement of the first extension steel bar in an embodiment of the present invention.

[0025] Figure 7 This is a schematic diagram of the arrangement of the second and third extension bars in an embodiment of the present invention.

[0026] Figure 8 This is a schematic diagram of the arrangement of the grouting conduit according to an embodiment of the present invention.

[0027] Figure 9This is a schematic diagram of the cross-sectional structure of the anti-slide pile driven into the soil according to an embodiment of the present invention.

[0028] Figure 10 This is a schematic diagram of the grouting head according to an embodiment of the present invention.

[0029] Figure 11 This is a schematic diagram of the deployment of prestressed anchor bolts according to an embodiment of the present invention.

[0030] Figure 12 This is a schematic diagram of the reinforcement of an I-shaped anti-slide pile according to an embodiment of the present invention.

[0031] Figure 13 This is a schematic diagram of the reinforcement structure of a rectangular anti-slide pile.

[0032] Figure 14 This is a schematic diagram illustrating the cooperation between the first stop bar and the second stop bar in an embodiment of the present invention.

[0033] Explanation of reference numerals in the attached figures: 101. Anti-slide pile insertion section; 102. Anti-slide pile cantilever section; 103. Frontal flange; 104. Backward flange; 1051. Raised strip; 1052. Groove; 1053. First retaining strip; 1054. Second retaining strip; 201. First prestressed duct; 202. Second prestressed duct; 203. Prestressed tendon; 301. Central pipe; 302. Grouting branch pipe; 303. Grout outlet; 306. First grouting. 307. Second grouting conduit; 308. Third grouting conduit; 401. Precast retaining wall; 501. Longitudinal wet joint; 502. Transverse wet joint; 601. Ground line on the back side of the soil; 602. Ground line on the front side of the soil; 701. First extension steel bar; 702. Second extension steel bar; 703. Third extension steel bar; 801. Grouting head; 802. Airbag; 803. Air pipe; 900. Prestressed anchor rod. Detailed Implementation

[0034] The present application will now be described in detail with reference to the accompanying drawings and embodiments. Various examples are provided by way of explanation and not by way of limitation. In fact, those skilled in the art will recognize that modifications and variations can be made to the present application without departing from the scope or spirit thereof. For example, a feature shown or described as part of one embodiment may be used in another embodiment to produce yet another embodiment. Therefore, it is desirable that the present application encompass such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0035] In the following description, the terms "first / second / third" are used merely to distinguish similar objects and do not represent a specific order of objects. It is understood that "first / second / third" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing embodiments of this disclosure only and is not intended to limit this disclosure.

[0037] In the description of this application, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and do not require this application to be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0038] like Figures 1 to 12 As shown, a novel anti-slide pile includes several I-shaped cross-section anti-slide piles and a precast retaining plate 401 fixed between two adjacent anti-slide piles. The anti-slide pile includes an anti-slide pile insertion section 101 and an anti-slide pile cantilever section 102. The insertion section 101, cantilever section 102, and precast retaining plate 401 are all precast reinforced concrete components. The insertion section 101 and cantilever section 102 are connected by a transverse wet joint 502. The precast retaining plate 401 is installed between two adjacent cantilever sections 102. The I-shaped cross-section anti-slide pile includes a back slope flange 104, an up slope flange 103, and a web plate vertically fixed between them. Prestressed steel strands are installed within the web plate of the I-shaped cross-section anti-slide pile. Grouting conduits are installed within the up slope flange 103 and the back slope flange 104 of the I-shaped cross-section anti-slide pile. The grouting conduit includes a soil-facing wing plate 103 installed on the soil-facing side of the I-shaped section anti-slide pile and a plurality of grouting branch pipes 302 distributed in the soil-facing wing plate 104 in the rock height direction. The grouting branch pipes 302 are connected to the surface of the I-shaped section anti-slide pile and form a plurality of grout outlets 303 on its surface. The grout outlets 303 are only installed on the side adjacent to the soil. If there is soil on both sides of the wing plate (e.g., the soil-entry section 101 of the anti-slide pile), then grout outlets 303 need to be installed on both sides of the wing plate. Figure 1 The ground line 602 on the soil-facing side and the ground line 601 on the soil-repellent side are schematically drawn when setting up on site.

[0039] There are two ways to install the precast retaining plate 401. The first way is to connect the two end faces of the precast retaining plate 401 to the two adjacent anti-slide pile cantilever sections 102 through longitudinal wet joints 501. The second way is to insert the precast retaining plate 401 between the two adjacent anti-slide pile cantilever sections 102.

[0040] Furthermore, such as Figures 2-5 , Figure 8 As shown, the grouting conduit includes a grouting main pipe, several main branch pipes vertically connected to the grouting main pipe, and several secondary branch pipes vertically connected to the main branch pipes; one main branch pipe and the secondary branch pipes connected to it constitute a grouting branch pipe 302, and the free ends of the main branch pipes and the free ends of the secondary branch pipes are the grout outlets 303; since the anti-slide pile insertion section 101 and the anti-slide pile cantilever section 102 are prefabricated in the factory, the grouting conduit is pre-embedded in the two anti-slide pile sections respectively; the anti-slide pile insertion section 101 has a back soil wing plate 104 and a front soil wing plate Grouting conduits are pre-embedded in sections 103. The grouting conduit pre-embedded in the soil-facing flange 103 of the anti-slide pile entry section 101 is designated as the first grouting conduit 306, and the grouting conduit pre-embedded in the soil-repellent flange 104 of the anti-slide pile entry section 101 is designated as the third grouting conduit 308. In the cantilever section 102 of the anti-slide pile, only the soil-facing flange 103 has a pre-embedded grouting conduit, designated as the second grouting conduit 307. Before the construction of the transverse wet joint 502, the first grouting conduit 306 and the second grouting conduit 307 are connected by a central pipe 301. The first grouting conduit 306 and the second grouting conduit 307 are installed longitudinally along the soil-facing flange 103. The grouting conduits are made of ordinary steel pipes, plastic pipes, or other conventional pipe materials. Alternatively, compressible rubber rods can be pre-embedded during prefabrication, and the rubber rods can be pulled out after the concrete has solidified to form grouting channels.

[0041] Furthermore, the spacing of the grouting branch pipes 302 can be adjusted according to the site requirements; at least two grouting branch pipes 302 are provided in the soil entry section 101 of the anti-slide pile, and at least one grouting branch pipe 302 is provided in the cantilever section 102 of the anti-slide pile; each grouting branch pipe 302 forms several grout outlets 303 on the side of the anti-slide pile in contact with the soil. In a specific example, the main grouting pipe is arranged in the middle of the two flanges of the I-shaped section, and the diameter of the main grouting pipe is 70-110mm; the diameter of the main and secondary branch pipes of the grouting branch pipes 302 is 40-60mm, the spacing between the main and branch pipes (i.e., the height difference of the grout outlets 303 at different heights) is 1-2m, and the lateral spacing of the grout outlets 303 on the same surface is 0.5-1m. Specifically, for the anti-slide pile insertion section 101, the grout outlets 303 should be at least on its soil-facing and soil-repellent surfaces, and may or may not be provided at the ends of the flanges; for the anti-slide pile cantilever section 102, the two ends of the soil-facing flange 103 should be connected to retaining plates, and grout outlets 303 do not need to be provided. The soil-repellent surface is open, and grout outlets 303 do not need to be provided there either. Therefore, the grout outlets 303 only need to be provided on the soil-facing surface of the anti-slide pile cantilever section 102. Figure 1-9 In the process, each grouting branch pipe 302 has 7 grout outlets 303 formed on each flange of the anti-slide pile cantilever section 102.

[0042] Furthermore, the anti-slide pile insertion section 101 and the anti-slide pile cantilever section 102 are made of high-strength steel bars and concrete, such as HRB500 high-strength steel bars and C50 or higher high-strength concrete. During prefabrication, the anti-slide pile insertion section 101 and the anti-slide pile cantilever section 102 are equipped with lifting holes to facilitate on-site installation.

[0043] Furthermore, the width and thickness of the soil-facing flange 103, soil-repellent flange 104, and web of the I-section anti-slide pile are determined based on structural calculations. In this embodiment, the thickness of the soil-facing flange 103 of the I-section anti-slide pile is equal to the thickness of the soil-repellent flange 104, the width of the soil-facing flange 103 is less than the width of the soil-repellent flange 104, and the thickness of the web of the I-section anti-slide pile is greater than the thickness of its soil-facing / soil-repellent flange 104.

[0044] Furthermore, compared to I-beams (with a height below 800mm), the height of the I-section anti-slide piles of this invention (between the outer surface of the soil-facing flange 103 and the outer surface of the soil-repellent flange 104) is greater, ranging from 2000 to 3000mm, resulting in stronger anti-slide capabilities. The embedment height and spacing of the I-section anti-slide piles are determined based on stress calculations (exposed height of the cantilever section 102 of the anti-slide pile and soil conditions). For example, if the upper layer is completely weathered sandstone and the lower layer is shale, with an exposed height of 13m, then the pile spacing between two I-section anti-slide piles is 5m, with an embedment height of 11m (the embedment section 101 of the anti-slide pile is 11mm long), and the precast retaining plate 401 is 40cm thick. The I-section anti-slide piles of this invention can be extended, and the height of the I-section anti-slide piles can be adjusted within a certain range by changing the length of the wet joint. The prestressing curve can be flexibly arranged according to actual needs, and the prestressing duct generally uses corrugated pipe with a diameter of 100mm (standard diameter). The prestressed steel strands can be adjusted according to actual needs. For example, there are 4 prestressed steel strands, each with 15 steel strands. Each steel strand has a diameter of 15.2 mm and a stress of 1960 MPa, which can be expressed as 15Φ15.2(1960).

[0045] Furthermore, such as Figure 6 , 7As shown, the upper end of the anti-slide pile insertion section 101 is reserved with a first extension steel bar 701, the lower end of the anti-slide pile cantilever section 102 is reserved with a second extension steel bar 702, the side of the anti-slide pile cantilever section 102 facing the precast retaining plate 401 is reserved with a third extension steel bar 703, and the two sides of the precast retaining plate 401 are reserved with fourth extension steel bars. The first extension steel bar 701 and the second extension steel bar 702 are welded and fixed or mechanically connected by steel bar threaded sleeves to ensure the continuity and bearing capacity of the main structure of the anti-slide pile in the high stress zone. The third extension steel bar 703 and the fourth extension steel bar are welded and fixed or mechanically connected by steel bar threaded sleeves to achieve a reliable connection between the retaining plate and the anti-slide pile. Figure 7 The diagram schematically shows the third extension steel bar 703 located at the outermost edge, which is only set on one side of the soil-facing flange 103 of the cantilever section 102 of the anti-slide pile; Figure 12 The diagram schematically shows the third extension steel bar 703 located on the non-edge side, which is set on both sides of the soil-facing flange 103 of the cantilever section 102 of the anti-slide pile.

[0046] This invention also proposes a construction method for the aforementioned novel anti-slide pile, comprising the following steps: Step P1: Prefabricate the anti-slide pile insertion section 101, the anti-slide pile cantilever section 102, and the prefabricated retaining plate 401 in the factory. The anti-slide pile insertion section 101 contains pre-embedded grouting pipes and tensioned prestressed steel strands. The lower end of the prestressed steel strands is anchored inside the anti-slide pile insertion section 101, and the upper end is anchored to the outside of the anti-slide pile insertion section 101 via connectors for subsequent extension. The anti-slide pile cantilever section 102 contains pre-embedded grouting pipes and prestressed pipes. Figure 2-5 The diagram schematically shows the prestressed duct (denoted as the first prestressed duct 201) in the soil-entry section 101 of the anti-slide pile and the prestressed duct (denoted as the second prestressed duct 202) in the cantilever section 102 of the anti-slide pile. Since the anti-slide pile embedded section 101 and the anti-slide pile cantilever section 102 need to be hoisted on site, the anti-slide pile embedded section 101 and the anti-slide pile cantilever section 102 can be prefabricated in sections according to the hoisting capacity, and then connected on site using wet joints. It should be noted that during factory prefabrication, the anti-slide pile insertion section 101 and the anti-slide pile cantilever section 102 are prefabricated laterally. The "lower end" and "upper end" of the prestressed steel strands here refer to the orientation of the prestressed steel strands when used on site. Step P2: Drill holes on site according to the design location; rotary drills or hydraulic square drills can be used for hole drilling, or manual excavation can be used. Step P3: On-site installation of I-section anti-slide piles; First, place the anti-slide pile drive section 101 into the pre-dug hole. After adjusting the verticality of the drive section 101, backfill and compact the soil in layers around it until it reaches the original ground level, specifically backfilling to the ground line 601 on the back soil surface; Place several pads (such as concrete pads) on the top surface of the drive section 101, and place the cantilever section 102 of the anti-slide pile on the pads; Insert the steel strand through the lower end of the prestressed duct of the cantilever section 102 of the anti-slide pile, and fix the lower part of the steel strand to the connector. Connect the grouting pipe of the drive section 101 to the grouting pipe of the drive section 101 through the central pipe 301. Figure 8 The diagram simplifies the anti-slide pile insertion section 101 and the anti-slide pile cantilever section 102, and schematically illustrates the connection between the first grouting conduit 306 and the second grouting conduit 307. Then, templates are installed around the interface of the anti-slide pile insertion section 101 and the anti-slide pile cantilever section 102, and concrete is poured for the transverse wet joint 502. After the concrete strength of the transverse wet joint 502 reaches the design requirements, steel strands are tensioned and grouting is performed at the top of the prestressed ducts of the anti-slide pile cantilever section 102. Preferably, the prestressed ducts are installed in pairs, and grout is pumped from one prestressed duct to the other during grouting, ensuring the grouting quality of the prestressed ducts. After the cantilever section is installed and the wet joint between the insertion section and the cantilever section is poured, tensioning is prioritized to form an integral structure of the I-section anti-slide pile, providing a certain anti-slide capability and a stable I-section anti-slide pile body for the installation of the precast retaining plate 401. Step P4: Install the precast retaining plate 401 between the two I-section anti-slide piles; Step P5: Inject grout into the grouting pipe. The grout flows out of the I-shaped anti-slide pile and enters the surrounding soil layer to reinforce the surrounding soil.

[0047] Furthermore, in step P4, when the precast retaining plate 401 is used with a longitudinal wet joint 501, the precast retaining plate 401 is placed between two I-section anti-slide piles, the formwork is installed, and the concrete for the longitudinal wet joint 501 is poured. At this time, in order to enhance the connection between the large anti-slide pile retaining plates and to better transmit force, preferably, during the precasting of the precast retaining plate 401 and the cantilever section 102 of the anti-slide pile, as follows... Figure 12 As shown, protruding strips 1051 and grooves 1052 are respectively provided on the left and right end faces of the soil-facing flange 103 of the cantilever section 102 of the anti-slide pile. Similar protruding strip or groove structures can also be provided on the left and right end faces of the precast retaining plate 401. When the precast retaining plate 401 is installed using a plug-in method, such as... Figure 14As shown, a first retaining strip 1053 with a thickness of about half the thickness of the wing plate 103 extends from both ends of the anti-slide pile cantilever section 102 on the soil-facing side. A second retaining strip 1054 with a thickness of about half the thickness of the wing plate extends from both ends of the precast retaining plate 401 on the soil-facing side. The extension length of the first retaining strip 1053 and the second retaining strip 1054 is about 500mm (450-550mm). During on-site installation, the precast retaining plate 401 only needs to be inserted between the two anti-slide piles. The bottom of the precast retaining plate 401 is supported by the ground. The first retaining strip 1053 and the second retaining strip 1054 can be tightly attached to each other after the soil-facing side of the precast retaining plate 401 is compressed. Compared with the two being connected by a wet joint, the insertion installation method can further improve the on-site construction efficiency.

[0048] The transverse wet joint 502 and the longitudinal wet joint 501 are made of high-strength micro-expansion concrete. The high-strength micro-expansion concrete is one grade higher than the concrete used for the precast retaining plate 401 and the I-shaped anti-slide piles on both sides of the joint. The high-strength micro-expansion concrete will produce micro-expansion in the early stage of hardening, thereby effectively offsetting the shrinkage stress in the later stage, preventing cracking, and ensuring a tight bond between the new and old concrete.

[0049] Furthermore, in step P2, the hole depth is equal to the longitudinal length of the anti-slide pile insertion section 101; the hole diameter is 200-500 mm larger than the outer diameter of the I-shaped cross-section anti-slide pile.

[0050] Furthermore, step P3 employs a single-end tensioning process; the connector is a commercially available prestressed steel strand multi-hole connector; during the prefabrication stage, the connector serves as the tensioning end of the 101 prestressed steel strand in the anti-slide pile's soil-entry section (referred to as the first prestressed section); during the on-site construction stage, the connector serves as the anchoring end of the 102 prestressed steel strand in the cantilever section of the anti-slide pile (referred to as the second prestressed section). In practical use, only the first prestressed section can be tensioned first. After the grouting of the first prestressed section is completed, the second prestressed steel strand is hung on the slots around the connector as the anchoring end of the second prestressed section.

[0051] Furthermore, in step P3, a conical cover is connected to the lower end of the prestressed duct (corrugated pipe) of the anti-slide pile cantilever section 102 beforehand. After the anti-slide pile cantilever section 102 is placed on the pad, the conical cover can cover the connector. After the prestressed steel strands of the anti-slide pile cantilever section 102 are tensioned, when grout is injected into the prestressed duct (corrugated pipe), the grout will fill the gap between the steel strands and the conical cover.

[0052] Furthermore, in step P3, before the anti-slide pile cantilever section 102 is placed on the anti-slide pile soil entry section 101, the opposite surfaces of the anti-slide pile soil entry section 101 and the anti-slide pile cantilever section 102 are roughened respectively; before the formwork is installed, the first extension steel bar 701 and the second extension steel bar 702 are welded or mechanically connected by steel bar straight thread sleeves, etc.; in step P4, before the formwork is installed, the third extension steel bar 703 and the fourth extension steel bar are welded or mechanically connected by steel bar straight thread sleeves, etc. in the gap.

[0053] Furthermore, an air bladder 802 is fixed to the outer periphery of the grouting head 801, and the air bladder 802 is connected to an air tube 803, which can controllably inflate and deflate the air. In step P5, the grouting head 801, which can be inserted into the grouting conduit, is used for retractable grouting. During grouting, the grouting head 801 is first inserted along the main grouting pipe to the top of the lowest grouting branch pipe 302, and air is inflated into the air bladder 802 so that the air bladder 802 is tightly attached to the inner wall of the main grouting pipe. Grouting begins until the grouting within the range of the lowest grouting branch pipe 302 is completed. Then, the grouting head 801 is moved upward to the top of the next grouting branch pipe 302 to begin grouting. This cycle is repeated to complete the entire grouting process. During grouting, the airbag 802 is inflated to ensure it adheres tightly to the inner wall of the grouting conduit; when the grouting head 801 is moved upwards, the airbag 802 is deflated. Grouting is first performed at the lowest outlet 303. Before the grout initially sets, the grouting head 801 is moved upwards to the position corresponding to the outlet 303 of the previous layer and then grouted. This allows the grout from the upper and lower parts to combine. The entire grouting process is completed in this cycle. The thickness of the soil layer above the uppermost outlet 303 should be greater than 2m.

[0054] Furthermore, in step P1, when the anti-slide pile cantilever section 102 is prefabricated, anchor holes are reserved on its soil-facing flange 103; and according to the position of the anchor holes, the prestressed steel strands (denoted as prestressed strands 203) in the anti-slide pile soil-entry section 101 and the prestressed ducts in the anti-slide pile cantilever section 102 are arranged. Figure 11 The diagram schematically illustrates the direction of the prestressed tendon 203 when using anchor bolts, showing that it is consistent with... Figure 2-5 The orientation of the prestressing varies; In step P5, after the transverse wet joint 502 has initially set, the hole is drilled into the stable stratum along the designed inclination angle and depth. Then, the prestressed anchor rod 900 is inserted into the anchor rod hole and tensioned, locked, and grouted for anchoring. Finally, the soil around the pile is reinforced by grouting through the grouting pipe.

[0055] When grouting in step P5, the interval between two grouting sessions should be determined based on the initial setting test results of the grout, but should not exceed 4 hours. The grout injection rate should be 15% to 20%. The grouting slurry can be cement slurry or cement-water glass two-component slurry, and the grouting pressure should be 1.0 MPa to 7.0 MPa; when using cement-water glass two-component fast-setting slurry, the grouting pressure should not exceed 1.0 MPa. The water-cement ratio of the cement slurry can be 0.6 to 2.0, with 1.0 being commonly used. The grouting flow rate can be 7 to 10 L / min, and should not exceed 20 L / min.

[0056] like Figure 12 The diagram below is a schematic representation of an I-section anti-slide pile according to an embodiment of the present invention. Figure 13 To and Figure 12 The diagram shows a traditional rectangular cross-section anti-slide pile with equal width and height.

[0057] Comparison between rectangular cross-section anti-slide piles and I-shaped cross-section anti-slide piles: Rectangular section anti-slide pile: 2.5m high, 1.5m wide, C50 concrete, 30C28 longitudinal reinforcement for compression, 86C28 longitudinal reinforcement for tension, C16@100 (2) stirrups, shear bearing capacity 8580kN, bending bearing capacity 45000kN·m.

[0058] I-shaped anti-slide pile: 2.5m high, 0.4m thick web, C50 concrete, 1.5m wide and 0.45m thick compression flange (soil-facing flange), 1.0m wide and 0.4m thick tension flange (soil-reverse flange), 44C28 longitudinal reinforcement (soil-facing flange), 38C28 longitudinal reinforcement (soil-reverse flange), C16@100 (4) stirrups, 4 bundles of 15Φ15.2 (1960) prestressed steel, shear bearing capacity 9170kN, bending bearing capacity 45800kN·m.

[0059] Calculations show that the cross-sectional area of ​​the rectangular anti-slide pile is 3.75m². 2 The cross-sectional area of ​​the I-shaped anti-slide pile is 1.735m². 2 I-section anti-slide piles save 53.7% of concrete compared to rectangular section anti-slide piles. The cross-sectional area of ​​the Φ28 steel reinforcement is 615.8 mm². 2 Φ15.2 steel strand with a cross-sectional area of ​​140mm² 2 The amount of steel reinforcement used for the rectangular section anti-slide pile is 116 × 615.8 = 71432.8 mm. 2 The reinforcement usage for the I-section anti-slide pile is 82 × 615.8 = 50495.6 mm. 2 The amount of steel strand used is 4 × 15 × 140 = 8400 mm. 2 Therefore, the total amount of steel reinforcement (including steel strands) in the I-section anti-slide pile is 58895.6 mm. 2The I-section anti-slide pile saves 17.6% of steel reinforcement (including steel strands) compared to the rectangular section anti-slide pile. Furthermore, the I-section anti-slide pile has a 6.9% higher shear capacity and a 1.8% higher flexural capacity than the rectangular section anti-slide pile. This demonstrates that the I-section anti-slide pile of this invention can save raw materials while ensuring structural performance.

[0060] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A novel anti-slide pile, characterized in that: The system includes several I-shaped anti-slide piles and precast retaining plates (401) fixed between adjacent anti-slide piles. Each anti-slide pile includes an embedded section (101) and a cantilever section (102). The embedded section (101), cantilever section (102), and precast retaining plate (401) are all precast reinforced concrete components. The embedded section (101) and cantilever section (102) are connected by a transverse wet joint (502). The precast retaining plate (401)... The anti-slide pile is installed between two adjacent cantilever sections (102) of the anti-slide pile. The I-shaped anti-slide pile includes a back soil wing plate (104), a front soil wing plate (103), and a web plate vertically fixed between the two. The web plate of the I-shaped anti-slide pile is provided with prestressed steel strands. The front soil wing plate (103) and the back soil wing plate (104) of the I-shaped anti-slide pile are provided with grouting pipes. The grouting pipes extend to the surface of the I-shaped anti-slide pile to form several grout outlets (303) of different heights.

2. The novel anti-slide pile according to claim 1, characterized in that: The two end faces of the precast retaining plate (401) are connected to the two adjacent anti-slide pile cantilever sections (102) through longitudinal wet joints (501), or the precast retaining plate (401) is inserted between the two adjacent anti-slide pile cantilever sections (102).

3. The novel anti-slide pile according to claim 1, characterized in that: The grouting conduit includes a soil-facing wing plate (103) of the I-shaped section anti-slide pile and a number of grouting branch pipes (302) distributed in the soil-facing wing plate (104) in the rock height direction. The grouting branch pipes (302) are connected to the surface of the I-shaped section anti-slide pile and form a number of grout outlets (303) on its surface.

4. The novel anti-slide pile according to claim 3, characterized in that: At least two grouting branch pipes (302) are provided in the soil-entry section (101) of the anti-slide pile, and at least one grouting branch pipe (302) is provided in the cantilever section (102) of the anti-slide pile; each grouting branch pipe (302) forms several grout outlets (303) on the side of the anti-slide pile in contact with the soil.

5. The novel anti-slide pile according to claim 1, characterized in that: The upper end of the anti-slide pile insertion section (101) is reserved with a first extension steel bar (701), the lower end of the anti-slide pile cantilever section (102) is reserved with a second extension steel bar (702), the side of the anti-slide pile cantilever section (102) facing the precast retaining plate (401) is reserved with a third extension steel bar (703), and the two sides of the precast retaining plate (401) are reserved with a fourth extension steel bar; the first extension steel bar (701) is fixedly connected with the second extension steel bar (702), and the third extension steel bar (703) is fixedly connected with the fourth extension steel bar.

6. A construction method for a novel anti-slide pile as described in any one of claims 1-5, characterized in that, Includes the following steps: Step P1: Prefabricate the anti-slide pile insertion section (101), the anti-slide pile cantilever section (102), and the prefabricated retaining plate (401) in the factory. The anti-slide pile insertion section (101) is pre-embedded with grouting pipes and tensioned prestressed steel strands. The lower end of the prestressed steel strands is anchored inside the anti-slide pile insertion section (101), and the upper end is anchored outside the anti-slide pile insertion section (101) through connectors for subsequent extension. The anti-slide pile cantilever section (102) is pre-embedded with grouting pipes and prestressed pipes. Step P2: Drill holes on site according to the design location; Step P3: On-site installation of I-section anti-slide piles; First, place the anti-slide pile insertion section (101) into the pre-dug hole, adjust the verticality of the anti-slide pile insertion section (101), then backfill and compact the soil around the anti-slide pile insertion section (101) in layers until it reaches the original ground level; Place several pads on the top surface of the anti-slide pile insertion section (101), and place the anti-slide pile cantilever section (102) on the pads; Insert the prestressed duct from the lower end of the anti-slide pile cantilever section (102). The lower part of the steel strand is fixed to the connector and is connected to the grouting pipe of the anti-slide pile entry section (101) and the grouting pipe of the anti-slide pile cantilever section (102) through the middle pipe (301); then, the template is installed around the interface of the anti-slide pile entry section (101) and the anti-slide pile cantilever section (102), and the concrete of the transverse wet joint (502) is poured; after the concrete strength of the wet joint reaches the design requirements, the prestressed steel strand of the anti-slide pile cantilever section (102) is tensioned and grouting is performed. Step P4: Install the precast retaining plate (401) between the two I-section anti-slide piles; Step P5: Inject grout into the grouting pipe. The grout flows out of the I-shaped anti-slide pile and enters the surrounding soil layer to reinforce the surrounding soil.

7. The construction method of the novel anti-slide pile according to claim 6, characterized in that: In step P2, the hole depth is the same as the longitudinal length of the anti-slide pile insertion section (101); the hole diameter is 200-500 mm larger than the outer circle diameter of the I-shaped anti-slide pile.

8. The construction method of the novel anti-slide pile according to claim 6, characterized in that: In step P5, a grouting head (801) that can be inserted into the grouting pipe is used for backward grouting; first, grouting is performed at the lowest grout outlet (303) position. Before the grout initially sets, the grouting head (801) is moved up to the position of the corresponding grout outlet (303) of the previous layer and then grouting is performed. The entire grouting process is completed in this cycle; the thickness of the overburden layer at the position of the uppermost grout outlet (303) should be greater than 2m.

9. The construction method of the novel anti-slide pile according to claim 8, characterized in that: An air bladder (802) is fixed to the outer periphery of the grouting head (801). During grouting, the air bladder (802) is inflated so that it is tightly attached to the inner wall of the grouting conduit. When the grouting head (801) is moved upward, the air bladder (802) is deflated.

10. The construction method of the novel anti-slide pile according to claim 6, characterized in that: In step P1, when the anti-slide pile cantilever section (102) is prefabricated, anchor holes are reserved on its soil-facing flange (103); and the prestressed steel strands in the anti-slide pile soil-entry section (101) and the prestressed ducts in the anti-slide pile cantilever section (102) are arranged according to the position of the anchor holes. In step P5, after the transverse wet joint (502) has initially set, the hole is drilled into the stable stratum along the designed inclination angle and depth. Then, prestressed anchor rods (900) are inserted into the anchor rod holes and tensioned, locked, and grouted for anchoring. Finally, the soil around the pile is reinforced by grouting through the grouting pipe.

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