A waterproof anti-pull pile and construction method

Abstract

The present invention provides a waterproof pull-out resistant pile and a construction method, which relate to the technical field of pile foundation construction, and comprise a steel frame, wherein a plurality of bent steel bars with ends away from the axis of the steel frame are arranged at the top of the steel frame, a waterproof layer is arranged outside the steel frame below the bent steel bars, a water stop plate sleeved outside the steel frame is arranged between the waterproof layer and the bent steel bars, and a concave surface facing the waterproof layer is arranged on the water stop plate to guide seepage away from the bent steel bars and the steel frame; a foundation bottom plate wrapped with the water stop plate and the bent steel bars is arranged above the waterproof layer; in view of the problem that the waterproofness and corrosion resistance of the pull-out resistant piles cannot meet the demand at present, a water stop plate and a waterproof layer are arranged on the steel frame, and the concave surface structure of the water stop plate is utilized to guide seepage from under the waterproof layer, thereby blocking the seepage from surging to the position of the bent steel bars, and guiding the seepage to flow to the position away from the steel frame, thereby reducing the water content at the contact position of the steel frame, improving the waterproofness and thus improving the corrosion resistance.

Description

Technical Field

[0001] The invention relates to the technical field of pile foundation construction, and in particular to a waterproof anti-pulling pile and a construction method. Background Art

[0002] The construction of pull-out piles is one of the commonly used anti-floating technologies. Compared with ordinary pull-out piles, micro pull-out piles have stronger terrain adaptability and more flexible arrangement. Micro pull-out piles are constructed in the stratum, and their tension and mortar anchor (or fine sand concrete) are used to reinforce the stratum, so that the stratum and the foundation slab form an integral structure, so that the friction resistance of the micro pull-out piles is greater than the buoyancy of groundwater, thereby achieving anti-floating effect. At the same time, the pull-out piles are set as expanded bottom piles, and the lateral friction resistance between the pile and the soil is used to exert the expansion resistance of the expanded bottom part.

[0003] There are many anti-floating piles and construction methods in the currently disclosed technologies. A Chinese patent (publication number CN111236218A) discloses an anti-floating pile structure composed of glass fiber reinforcement and steel bar. However, the contact surface between the inner anchor and the outer anchor is not waterproofed. The anchor steel bar will rust under the action of corrosive groundwater in the later stage, and the durability cannot be guaranteed, which affects the normal use of the underground structure. A Chinese patent (publication number CN114482142A) discloses a large-diameter fine-rolled threaded steel anti-floating anchor rod. The spiral hoop ring and the outer anchor section at the top are not waterproofed, and the inner anchor section is not centered, which can easily cause the anti-floating anchor rod to tilt. The special anchor plate is prone to stress concentration at the bend, and the designed bearing capacity cannot be guaranteed. For the anti-floating piles in the prior art, the overall waterproof performance is poor, resulting in poor corrosion resistance of the pull-out piles, which affects the ultimate pull-out bearing capacity of the pull-out piles and is difficult to meet the anti-floating requirements. Summary of the invention

[0004] The purpose of the present invention is to provide a waterproof and pull-out resistant pile and a construction method in view of the defects of the prior art. A water stop plate and a waterproof layer are arranged on a steel frame, and the concave structure of the water stop plate is used to guide the seepage from under the waterproof layer, thereby blocking the seepage from surging to the bent steel bars and guiding the seepage to flow to a position away from the steel frame, thereby reducing the water content at the contact position of the steel frame, improving the waterproof performance and thus improving the corrosion resistance.

[0005] The first object of the present invention is to provide a waterproof anti-pulling pile, which adopts the following scheme:

[0006] It includes a steel frame, a plurality of bent steel bars with ends away from the axis of the steel frame are arranged on the top of the steel frame, a waterproof layer is arranged on the outer cover of the steel frame below the bent steel bars, a water stop plate arranged outside the steel frame is arranged between the waterproof layer and the bent steel bars, and a concave surface facing the waterproof layer is arranged on the water stop plate to guide the seepage water away from the bent steel bars and the steel frame; a foundation bottom plate wrapped with the water stop plate and the bent steel bars is arranged above the waterproof layer.

[0007] Furthermore, a plurality of water stop plates are arranged at intervals along the axial direction of the steel frame, and the concave surface areas of the water stop plates increase successively in the direction away from the waterproof layer along the axis of the steel frame.

[0008] Furthermore, a waterproof sleeve is provided outside the steel frame, and the waterproof sleeve is located between the water stop plate and the waterproof layer. An elastic layer for waterproofing is arranged around the waterproof sleeve. In the radial direction away from the axis of the steel frame, the height of the elastic layer gradually decreases, and a guide channel is formed between the elastic layer and the concave surface of the water stop plate.

[0009] Furthermore, along the axial direction of the steel skeleton, the maximum projection area of ​​the water stop plate on the waterproof layer is smaller than the projection area of ​​the elastic layer on the waterproof layer.

[0010] Furthermore, a protective layer is provided on the top surface of the waterproof layer, a cushion layer is provided on the bottom surface, and a pad is provided on the outer sleeve of the steel frame to fit the protective layer.

[0011] Furthermore, the bent steel bars are located on one side of the waterproof layer, and a positioning frame and a centering bracket are provided on the corresponding steel frame on the other side of the waterproof layer. The centering bracket includes a hoop, a screw rod and an arc plate. The hoop is connected to the steel frame, and the screw rod is arranged radially along the steel frame. One end of the screw rod cooperates with the hoop, and the other end is connected to the arc plate. The convex surface of the arc plate faces the side away from the steel frame.

[0012] Furthermore, a plurality of centering brackets are arranged around the steel bar skeleton, and the plurality of brackets are evenly spaced and distributed in the circumferential direction relative to the steel bar skeleton.

[0013] Furthermore, the bent steel bars are connected with anchor plates, the plane where the anchor plates are located is perpendicular to the axis of the connected bent steel bars, the anchor plates are buried in the foundation slab, and the bottom end of the steel bar skeleton is connected with the anchor plates.

[0014] The second object of the present invention is to provide a construction method of the waterproof anti-pulling pile as described in the first object, comprising:

[0015] Drill holes, make steel skeletons and bend steel bars, and install water stop plates on the steel skeletons;

[0016] The bottom end of the steel frame is lowered into the drilled hole, the water stop plate is kept at a distance from the drilled hole opening, and grouting is performed for maintenance;

[0017] A waterproof layer is laid around the steel frame on the ground, and concrete is poured on top of the waterproof layer to wrap the steel frame, water stop plate and bent steel bars to form a foundation slab.

[0018] Furthermore, the anchor plate is located in the foundation bottom plate, a waterproof casing is arranged at the drilling opening position, and the outer circumference of the waterproof casing is connected to the waterproof layer.

[0019] Compared with the prior art, the present invention has the following advantages and positive effects:

[0020] (1) In order to solve the problem that the waterproofness and corrosion resistance of the pull-out piles cannot meet the demand, a water stop plate and a waterproof layer are arranged on the steel frame. The concave structure of the water stop plate is used to guide the seepage from under the waterproof layer, blocking the seepage from surging to the bent steel bars and guiding the seepage to flow away from the steel frame, thereby reducing the water content at the contact position of the steel frame, improving the waterproof performance and thus improving the corrosion resistance.

[0021] (2) In order to meet the pull-out strength of the pull-out pile, the steel skeleton and bent steel bars are made of hot-rolled ribbed steel bars with high tensile strength. The top extension of the steel skeleton is bent to form bent steel bars, which changes the direction of the steel bars and improves the tensile performance. Double anchor plates are installed at the top of the bent steel bars to increase the stress-bearing area between the bent steel bars and the foundation slab.

[0022] (3) Multiple waterstop plates are used to connect the steel frame. The waterstop plates are buried in the foundation slab. The waterproof casing and the elastic layer made of high elastic material for waterproofing can effectively improve the corrosion resistance of the micro-pull-out piles, improve the safety of the pull-out structural system and the building (structure), and the arrangement of the waterstop plates with special structures also has the effect of increasing the contact area with the foundation slab concrete, thereby improving its pull-out bearing capacity.

[0023] (4) The positioning frame installed in the pile hole can make the multiple steel bars constituting the steel skeleton form a whole, bear the force synergistically, increase the contact area between the steel skeleton and the mortar (or fine stone concrete), enhance the bonding force between the steel skeleton and the mortar, and improve the ultimate pull-out bearing capacity of the micro-pull-out pile. At the same time, the increase in the contact area between the steel skeleton and the mortar can also reduce the cracking of the micro-pull-out pile, and enhance the integrity and force-bearing performance of the micro-pull-out pile.

[0024] (5) The centering bracket can keep the steel skeleton upright during the construction process, ensuring that the verticality of the steel skeleton of the micro-pullout pile meets the requirements after pouring mortar (or fine stone concrete). At the same time, it ensures that the steel skeleton of the micro-pullout pile has a protective layer of sufficient thickness, effectively inhibiting the erosion of groundwater on the steel bars, and ensuring that the long-term pull-out bearing capacity of the micro-pullout pile meets the design requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] Figure 1 It is a schematic structural diagram of the waterproof and pull-out resistant piles in Example 1 or 2 of the present invention.

[0027] Figure 2It is a schematic diagram of the structure of the steel bar skeleton in Example 1 or 2 of the present invention.

[0028] Figure 3 It is a schematic top view of the pad in Example 1 or 2 of the present invention.

[0029] Figure 4 It is a schematic side view of the pad in Example 1 or 2 of the present invention.

[0030] Figure 5 It is a schematic top view of the waterproof sleeve in Embodiment 1 or 2 of the present invention.

[0031] Figure 6 It is a schematic diagram of the structure of the positioning frame in Example 1 or 2 of the present invention.

[0032] Figure 7 It is a schematic structural diagram of the centering bracket in Example 1 or 2 of the present invention.

[0033] Figure 8 It is a schematic diagram of the structure of the anchor plate in Example 1 or 2 of the present invention.

[0034] Fig. 9 It is a schematic top view of the anchor plate in Example 1 or 2 of the present invention.

[0035] Fig.10 It is a schematic top view of the water stop plate in Embodiment 1 or 2 of the present invention.

[0036] Fig.11 It is a front view schematic diagram of the water stop plate in embodiment 1 or 2 of the present invention.

[0037] In the figure, 1 is drilled hole, 2 is waterproof layer, 3 is cushion layer, 4 is foundation bottom plate, 5 is main reinforcement, 6 is bent reinforcement, 7 is waterproof casing, 8 is pad, 9 is positioning frame, 10 is first water stop plate, 11 is second water stop plate, 12 is anchor plate, 13 is first anchor plate, 14 is second anchor plate, 15 is protective layer, 16 is centering bracket, 17 is elastic layer, 18 is reinforcement skeleton, 16-1 is arc-shaped steel sheet, 16-2 is inner threaded steel sleeve, 16-3 is circular steel pipe, 16-4 is bolt, 16-5 is nut, 16-6 is wire rod. DETAILED DESCRIPTION

[0038] Example 1

[0039] In a typical embodiment of the present invention, Figure 1-Figure 11 As shown, a waterproof anti-pulling pile is provided.

[0040] like Figure 1The waterproof and pull-out resistant piles shown are arranged in the stratum where anti-floating is required, and the waterproof layer 2, elastic layer 17, waterproof casing 7 and water stop plate work together to achieve water isolation and water diversion above the stratum. The water stop plate adopts a concave structure to guide the seepage water, so that the seepage water flows along the oblique downward path, thereby away from the steel skeleton and bent steel bars 6, reducing the water content in the corrosion-prone position and improving the waterproof performance.

[0041] In this embodiment, Figure 1 , Figure 6 As shown, the steel frame is a steel cage structure formed by three steel bars reinforced by a positioning frame 9. Compared with other pull-out piles, the steel bars extending from the top of the steel cage in the pull-out pile are bent, and an anchor plate is arranged outside the bend to improve the anchoring force between the pull-out pile and the poured foundation slab 4. The steel bars are subjected to coordinated force through the positioning frame 9 to improve the pull-out bearing capacity.

[0042] It is understandable that in other embodiments, the steel bar skeleton may include other numbers of steel bars, such as four, five, etc., and be fixed with corresponding positioning frames 9 to form the required steel bar cage structure.

[0043] like Figure 1 As shown, the waterproof pull-out resistant pile mainly includes a steel frame, and a plurality of bent steel bars 6 with ends away from the axis of the steel frame are provided at the top of the steel frame. The bent steel bars 6 are part of the steel frame, extending from the top of the steel frame to the outside of the main structure of the steel frame, and the bent steel bars 6 are arranged at an angle to the axis of the steel frame.

[0044] like Figure 2 As shown, the axis of the bent steel bar 6 forms an obtuse angle with the axis of the steel bar skeleton, and one end of the bent steel bar 6 connected to the steel bar skeleton is closer to the steel bar skeleton than the other end of the bent steel bar 6, forming an outwardly extending structure to facilitate the subsequent arrangement of the anchor plate.

[0045] A waterproof layer 2 is provided on the outer sleeve of the steel frame below the bent steel bars 6, and a waterstop plate is provided between the waterproof layer 2 and the bent steel bars 6 and is sleeved on the outer sleeve of the steel frame. The waterproof layer 2 can prevent water in the stratum from leaking to the stratum above. Since the steel frame needs to pass through the waterproof layer 2, the waterproof layer 2 forms an opening at the position of the steel frame. The waterproof layer 2 cannot directly cover the opening position, and the formation water can easily leak from the opening position to the stratum above. In addition, there is a steel frame structure at this position, which will induce corrosion problems during leakage. The waterstop plate is arranged to prevent the water from further extending upward.

[0046] At the same time, the water stop plate is provided with a concave surface facing the waterproof layer 2 to guide the seepage water away from the bent steel bars 6 and the steel skeleton; a base bottom plate 4 wrapping the water stop plate and the bent steel bars 6 is provided above the waterproof layer 2.

[0047] When arranging waterproof pull-out piles, it is necessary to first form a borehole 1, and a down-the-hole drill is used to drill the hole. The down-the-hole drill is suitable for construction in any rock and soil layer, including hard rock formations. According to the design bearing capacity requirements, the hole is enlarged at the bottom of the hole to form an enlarged head. The pull-out pile borehole 11 after the hole enlargement process can provide sufficient anchoring space for the end of the steel frame and the locking anchor plate 12 connected to the end of the steel frame, thereby increasing the overall pull-out bearing capacity of the pull-out pile.

[0048] It is understood that the diameter of the pull-out pile drilling hole 1 is not less than 200 mm, and the radius of the hollow sphere formed by the bottom expansion hole is not less than 400 mm. The specific size is determined comprehensively according to the actual pull-out requirements and the construction parameters of the construction equipment. Micro pull-out piles are different from ordinary pull-out piles. The diameter range of micro pull-out piles is 100 mm-400 mm.

[0049] A waterproof sleeve 7 is provided outside the steel frame, and the waterproof sleeve 7 is located between the water stop plate and the waterproof layer 2. An elastic layer 17 for waterproofing is arranged around the waterproof sleeve 7. In the radial direction away from the axis of the steel frame, the height of the elastic layer 17 gradually decreases, and a guide channel is formed between the elastic layer 17 and the concave surface of the water stop plate.

[0050] like Figure 1 , Figure 5 As shown, the waterproof layer 2 and the waterproof casing 7 are both made of asphalt composite flexible waterproof membrane. The waterproof casing 7 needs to completely wrap the steel frame from the ground upwards and be paved over a certain area along the horizontal direction of the ground. The paving area on the ground should not be less than the projection area of ​​the water stop plate on the waterproof layer 2.

[0051] The foundation slab 4 is a cast-in-place reinforced concrete slab. To ensure the bonding strength between the foundation slab 4 and the bent steel bars 6, the thickness of the foundation slab 4 should not be less than 400 mm. The foundation slab 4 is internally arranged with main bars 5. The main bars 5 are arranged in two layers and in two directions according to the specification. The diameter of the main bars 5 is greater than or equal to 16 mm, and the distance between adjacent main bars 5 is less than or equal to 200 mm. The main bars 5 are arranged throughout the entire length. For specific construction requirements, refer to the existing construction specifications.

[0052] like Figure 1 As shown, a plurality of water stop plates are arranged at intervals along the axial direction of the steel frame, and the concave area of ​​the water stop plates increases in sequence in the direction away from the waterproof layer 2 along the axis of the steel frame. In this embodiment, two water stop plates are arranged, namely a first water stop plate 10 and a second water stop plate 11. The second water stop plate 11 is located above the first water stop plate 10. Compared with the first water stop plate 10, the second water stop plate 11 is arranged closer to the bent steel bar 6.

[0053] like Figure 1 , Figure 8 , Fig. 9As shown, the bent steel bar 6 is connected with an anchor plate, the plane where the anchor plate is located is perpendicular to the axis of the connected bent steel bar 6, the anchor plate is buried in the foundation bottom plate 4, and the bottom end of the steel bar skeleton is connected with an anchor plate 12. In this embodiment, two anchor plates are arranged on each bent steel bar 6, the two anchor plates are arranged at intervals, and have different areas, namely the first anchor plate 13 and the second anchor plate 14.

[0054] The bent steel bar 6 is a hot-rolled ribbed steel bar, which can increase the bond strength between the steel bar and the concrete. The specific model and length are configured according to the pull-out resistance requirements. The distance between the bent part where the bent steel bar 6 connects to the main body of the steel bar skeleton and the second water stop plate 11 is 10 cm, and the axial length of the bent steel bar 6 can be selected as 40 cm. The bending angle of the bent steel bar 6 is configured according to the requirements. At the same time, the steel bar skeleton in this embodiment is welded to form a whole with the first water stop plate 10, the second water stop plate 11, the first anchor plate 13, the second anchor plate 14, the positioning frame 9, and the anchor plate 12.

[0055] like Figure 1 , Figure 3 , Figure 4 As shown, a protective layer 15 is provided on the top surface of the waterproof layer 2, a cushion layer 3 is provided on the bottom surface, and a pad 8 that fits the protective layer 15 is provided on the outer sleeve of the steel frame.

[0056] In this embodiment, the pad 8 is a square steel plate, and its area needs to be larger than the anti-pullout pile drilling hole 1. The distance from the first water stop plate 10 is determined according to the designed pile burrowing depth. Holes are reserved in the pad 8 for the steel skeleton and the grouting pipe to pass through. The holes correspond to the positions of the steel bars constituting the steel skeleton. The diameter of the hole required for the grouting pipe is 32mm.

[0057] In order to ensure the bearing capacity requirements of the pad 8, its thickness is configured to be greater than or equal to 20 mm according to the needs. The pad 8 can be welded with the steel frame to form a whole. After the anti-pullout pile drilling hole 1 is formed, when the steel frame is lowered, it can prevent the steel cage from touching the bottom, providing sufficient bonding space for the bottom of the steel frame and the mortar.

[0058] like Figure 6 As shown, the positioning frame 9 is welded by thin steel bars, and is a triangular prism as a whole. The side surface is composed of three rectangles, and the upper and lower ends are triangles, which can wrap the steel skeleton, and its size is the same as the side area of ​​the structure composed of the steel skeleton. The positioning frame 9 is connected to the steel skeleton by welding, and three are evenly arranged along the vertical direction of the steel skeleton, so that the three steel skeletons can form an integral structure, thereby improving the bearing capacity of the pull-out pile.

[0059] like Fig.10 , Fig.11As shown, the structures of the multiple waterstop plates are similar but the sizes are different. In this embodiment, the first waterstop plate 10 is taken as an example. The structures of the other waterstop plates are the same as the first waterstop plate 10, but the size specifications are configured according to the requirements. The first waterstop plate 10 is composed of a square steel plate and two rectangular steel plates. The upper part of the first waterstop plate 10 is a square steel plate with a side length of 30cm and a thickness of 5mm, and the two sides are rectangular steel plates with a size of 30cm*10cm*5mm. The rectangular steel plates are fixed to the two sides of the square steel plates by welding. The angle between the rectangular steel plates and the square steel plates is 150°, thereby forming a concave structure, and a concave surface is formed below the first waterstop plate 10.

[0060] like Figure 1 As shown, the first water stop plate 10 is welded 20cm below the bending of the steel frame. Compared with the ordinary square water stop plate, the water stop plate has rectangular steel plates added on both sides of the square water stop plate, which can play a role in preliminary waterproofing and reducing corrosion of the reinforcement, and on the other hand, it can also increase the contact area between the steel frame and the foundation bottom plate 4, and improve the overall pull-out bearing capacity of the pull-out pile.

[0061] It should be pointed out in particular that the concave structure of the water stop plate is used to guide the seepage from under the waterproof layer 2, blocking the seepage from surging to the position of the bent steel bars 6, and guiding the seepage to flow to a position away from the steel skeleton, thereby reducing the water content at the contact position of the steel skeleton, improving the waterproof performance and thus improving the corrosion resistance.

[0062] The second waterstop plate 11 has the same shape as the first waterstop plate 10. Its upper part is a square steel plate with a side length of 40 cm and a thickness of 5 mm, and its two side sides are rectangular steel plates with a size of 40 cm*10 cm*5 mm. The rectangular steel plates are fixed to the two sides of the square steel plates by welding, and the angle between the rectangular steel plates is 150°. The second waterstop plate 11 is welded 10 cm below the bending part of the steel frame, which can further reduce the corrosion of the bent steel bars 6 and increase the pull-out bearing capacity.

[0063] like Figure 8 , Fig. 9 As shown, the upper part of the anchor plate 1212 is a regular hexagonal prism with a height of 40mm and a side length of 40mm, and the lower part is a cylinder with a radius of 80mm. The central reserved hole can be firmly locked with the steel skeleton. The locking anchor plates 12 are arranged at the bottom ends of the steel skeletons, and the bottom ends of each steel bar constituting the steel skeleton are connected with a locking anchor plate 12, which can expand the contact area between the steel skeleton and the pile bottom hole expansion mortar and improve the bearing capacity.

[0064] like Figure 1 As shown, the first anchor plate 13 is a square steel plate with a side length of 20 cm and a thickness of 5 mm. It can be fixed by welding at 10 cm above the bending point of the steel skeleton, which can increase the contact area between the steel skeleton and the foundation bottom plate 4 and enhance the pull-out bearing capacity of the pull-out pile.

[0065] The second anchor plate 1414 is a square steel plate with a side length of 30 cm and a thickness of 5 mm, which is welded 20 cm above the bending point of the steel skeleton. The design of the double anchor plate can further increase the contact area between the anchor plate and the foundation bottom plate 4, thereby maximizing the pull-out bearing capacity of the structure.

[0066] like Figure 7 As shown, the centering bracket 16 includes a hoop, a screw and an arc plate. The hoop is connected to the steel frame. The screw is arranged radially along the steel frame. One end of the screw cooperates with the hoop and the other end is connected to the arc plate. The convex surface of the arc plate faces the side away from the steel frame.

[0067] The centering bracket 16 in this embodiment is a special structure. The arc plate adopts an arc steel sheet 16-1, the screw rod adopts a screw rod 16-6, and the hoop is composed of an inner threaded steel sleeve 16-2, a circular steel pipe 16-3, bolts 16-4, and nuts 16-5. It is composed of an arc steel sheet 16-1, an inner threaded steel sleeve 16-2, a circular steel pipe 16-3, bolts 16-4, nuts 16-5, and a screw rod 16-6. The thickness of the circular steel pipe 16-3 is 2mm and the width is 5cm. The diameter is determined by the steel skeleton. The two parts of the circular steel pipe 16-3 are connected into a ring by bolts 16-4 and nuts 16-5, which can be tightly fixed on the outer surface of the steel skeleton; the wire rod 16-6 is a solid iron rod with a diameter of 2cm and a length of 2cm, and has a thread on the surface. The diameter of the inner wire steel casing 16-2 is determined according to the diameter of the wire rod 16-6. The wire rod 16-6 is connected to the inner wire steel casing 16-2 by threaded matching, and its length is 2cm; the arc steel sheet 16-1 is welded to the outer end of the wire rod 16-6 to fix the steel skeleton. The centering bracket 16 can keep the steel skeleton in a vertical state during the sinking process, ensure the smooth lowering of the steel skeleton, and prevent the problem of the steel skeleton tilting after the anti-pullout pile is poured.

[0068] like Figure 1 As shown, the elastic layer 17 is used as a waterproof structure. The elastic layer 17 is a high-performance waterproof coating made of high-grade acrylic emulsion as the base material and various additives and fillers. After the anchoring section in the pull-out pile is constructed, the area around the hole is repeatedly painted with a rubber brush. The painted area should be larger than the area of ​​the second water stop plate 11. It needs to be painted into a shape with a high inside and a low outside, and the inner height is not less than 5 cm. The elastic layer 17 can keep the pull-out pile in good waterproof performance when it is strained by groundwater, and prevent groundwater seepage to avoid steel corrosion.

[0069] Example 2

[0070] In another typical embodiment of the present invention, Figure 1-Figure 11 As shown, a construction method of waterproof and anti-pullout piles is given.

[0071] The following steps are involved:

[0072] Drilling holes 1, making steel skeleton and bending steel bars 6, installing water stop plates on the steel skeleton;

[0073] The bottom end of the steel frame is lowered into the borehole 1, so that the water stop plate is spaced apart from the opening of the borehole 1, and grouting is performed for curing;

[0074] A waterproof layer 2 is laid on the ground around the steel frame, and concrete is poured above the waterproof layer 2 to wrap the steel frame, water stop plate and bent steel bars 6 to form a foundation slab 4.

[0075] Specific, combined Figure 1-Figure 11 , the above construction method includes the following specific steps:

[0076] 1. Pile hole positioning:

[0077] A total station is used to measure the elevation of the construction site and determine the depth of borehole 1. At the same time, the layout of the anti-pullout pile borehole 1 is measured to determine the position of borehole 1. According to the relevant requirements of the specifications and design drawings, the error of the hole layout should not be greater than 20mm, and the mechanical positioning error should not be greater than 50mm.

[0078] 2. Micro-pullout pile hole construction:

[0079] The drilling method of mechanical hole expansion is adopted. According to the on-site layout, the down-the-hole drill is moved to align the drill head with the hole center. Ensure that the drill reaches the verticality required by the design. After the drill is in place, it is horizontally corrected and then drilled. For weathered rock formations, especially medium-weathered rock formations, the bottom of the steel skeleton is expanded. The hole depth is confirmed on site and should not be less than the design length, nor more than 500mm of the design length.

[0080] 3. Production of micro-pullout pile steel frame:

[0081] Coordinate the production time and drilling time of the steel skeleton of the pull-out pile, and try to drill holes after the production is completed to reduce damage to the steel skeleton components. The first step is to weld the steel skeleton with the first water stop plate 10 and the second water stop plate 11. The second step is to insert the pad 8 from the bottom of the steel skeleton and install it to the predetermined position and weld it. The third step is to install the positioning frame 9, the centering bracket 16, the first anchor plate 13, and the second anchor plate 14 in the designated position in turn and weld them. Finally, install the locking anchor plates 12 at the bottom of the corresponding steel bars of the steel skeleton.

[0082] 4. Construction of the inner anchoring section of micro-pullout piles:

[0083] Use a drilling machine to hoist the steel skeleton as a whole and place it into the anti-pull pile drilling hole 1. Avoid twisting, bending and falling off of the steel skeleton during placement. The anti-pull pile grouting body is filled with pure cement slurry. The construction process adopts secondary grouting technology, and the grouting pressure is not less than 2.0MPa. The specific cement strength, water-cement ratio and grouting pressure are determined by the actual engineering requirements. After grouting, a curing period of more than 3 days is required before subsequent construction can be carried out. During the curing period, the steel skeleton must not be hit at will.

[0084] 5. Construction of waterproof layer 2:

[0085] After the construction of the inner anchoring section is completed, the waterproof layer 2 is paved. Before the waterproof layer 2 is constructed, a 100mm thick C20 fine stone concrete cushion layer 3 should be poured first for leveling and laying waterproof materials. Before pouring concrete, the accumulated water and debris on the foundation surface should be cleaned up, the flatness and elevation of the base layer should meet the requirements, and the foundation surface should be moistened. 12 hours after the concrete pouring of the cushion layer 3 is completed, it should be covered and watered immediately. The concrete surface should be kept moist. It is forbidden to enter too early and step on the concrete surface. The curing time should generally not be less than 7 days and nights. Then make a waterproof sleeve 7, install it at the orifice position, and lay another layer of waterproof membrane along the ground direction. The joint between the waterproof layer 2 and the waterproof sleeve 7 is hot-melt treated to make it flat after bonding, and it must not be twisted or arched. After the construction of the waterproof layer 2 is completed, a 40mm thick C20 fine stone concrete waterproof protective layer 15 is poured on the waterproof layer 22 to protect the waterproof layer 2 from damage during the subsequent construction process; finally, the elastic layer 17 is constructed at the hole, the surface of the waterproof protective layer 15 is cleaned, and the high-elastic waterproof material is applied to the surface with a roller or a harder paint brush, and the application is evenly crossed in a vertical direction to achieve the best coverage. Pay attention to avoid missing any spots, and finally make the elastic layer 17 high inside and low outside, with the inner height not less than 5cm.

[0086] 6. Construction of micro-pullout piles and foundation slab 4 anchoring sections:

[0087] Bind the main reinforcement 5 of the bottom plate. After the reinforcement is tied, formwork and bottom plate concrete are poured. After pouring, the concrete is cured within 8 to 12 hours. The curing time shall not be less than 7 days. The specific curing time shall be determined according to the actual project needs.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A waterproof and pull-out resistant pile, characterized in that: It comprises a steel frame, a plurality of bent steel bars with ends away from the axis of the steel frame are arranged at the top of the steel frame, a waterproof layer is arranged on the outer jacket of the steel frame below the bent steel bars, a water stop plate is arranged between the waterproof layer and the bent steel bars and is arranged outside the steel frame, and a concave surface facing the waterproof layer is arranged on the water stop plate to guide the seepage away from the bent steel bars and the steel frame; a foundation bottom plate is arranged above the waterproof layer to wrap the water stop plate and the bent steel bars; The water stop plates are arranged in a plurality of intervals along the axial direction of the steel frame. The concave areas of the water stop plates increase in sequence in the direction away from the waterproof layer along the axis of the steel frame. There are two water stop plates, namely the first water stop plate and the second water stop plate. The second water stop plate is located above the first water stop plate. Compared with the first water stop plate, the second water stop plate is arranged closer to the bent steel bar. The outer sleeve of the steel frame is provided with a waterproof sleeve, which is located between the water stop plate and the waterproof layer. An elastic layer for waterproofing is arranged around the waterproof sleeve. In the radial direction away from the axis of the steel frame, the height of the elastic layer gradually decreases, and a guide channel is formed between the elastic layer and the concave surface of the water stop plate. The elastic layer is used as a waterproof structure. The elastic layer is a high-performance waterproof coating made of high-grade acrylic emulsion as the base material and added with a variety of additives and fillers. After the anchoring section in the pull-out pile is completed, the area around the hole is repeatedly brushed with a rubber brush. The brushing area should be larger than the area of ​​the second water stop plate. It needs to be brushed into a shape of high inside and low outside, and the inner height is not less than 5cm. The maximum projection area of ​​the water stop plate on the waterproof layer is smaller than the projection area of ​​the elastic layer on the waterproof layer. The top surface of the waterproof layer is provided with a protective layer, and the bottom surface is provided with a cushion layer; the outer cover of the steel frame is provided with a cushion plate that fits the protective layer; The bent steel bar is located on one side of the waterproof layer, and a positioning frame and a centering bracket are provided on the corresponding steel bar skeleton on the other side of the waterproof layer. The centering bracket includes a hoop, a screw rod and an arc plate. The hoop is connected to the steel bar skeleton, and the screw rod is arranged radially along the steel bar skeleton. One end of the screw rod cooperates with the hoop, and the other end is connected to the arc plate, and the convex surface of the arc plate faces the side away from the steel bar skeleton. The positioning frame is welded from thin steel bars and is in the shape of a triangular prism. The side is composed of three rectangles and the upper and lower ends are triangles, which wrap around the steel skeleton. Its size is the same as the side area of ​​the structure composed of the steel skeleton. The positioning frame is connected to the steel skeleton by welding, and three of them are evenly arranged along the vertical direction of the steel skeleton. The waterproof layer and waterproof casing materials are both made of asphalt composite flexible waterproof membrane. The waterproof casing must completely wrap the steel skeleton from the ground upwards and be paved over a certain area along the horizontal direction of the ground. The paving area on the ground shall not be less than the projection area of ​​the water stop plate on the waterproof layer.

2. The waterproof anti-pulling pile according to claim 1, characterized in that: A plurality of centering brackets are arranged around the steel bar skeleton, and the plurality of brackets are evenly spaced and distributed in the circumferential direction relative to the steel bar skeleton.

3. The waterproof anti-pulling pile according to claim 1, characterized in that: The bent steel bars are connected with anchor plates, the plane where the anchor plates are located is perpendicular to the axis of the connected bent steel bars, the anchor plates are buried in the foundation slab, and the bottom end of the steel bar skeleton is connected with the anchor plates.

4. A construction method for waterproof and anti-pulling piles according to any one of claims 1 to 3, characterized in that: include: Drill holes, make steel skeletons and bend steel bars, and install water stop plates on the steel skeletons; The bottom end of the steel frame is lowered into the drilled hole, the water stop plate is kept at a distance from the drilled hole opening, and grouting is performed for maintenance; A waterproof layer is laid around the steel frame on the ground, and concrete is poured on top of the waterproof layer to wrap the steel frame, water stop plate and bent steel bars to form a foundation slab.

5. The construction method according to claim 4, characterized in that: An anchor plate is connected to the bent steel bar, the anchor plate is located in the foundation bottom plate, a waterproof casing is arranged at the drilling opening position, and the outer circumference of the waterproof casing is connected to the waterproof layer.

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