Steel rake tooth pile and designing, manufacturing and pile sinking construction method thereof

Abstract

The invention discloses a steel rake tooth pile and a designing, manufacturing and pile sinking construction method thereof. The steel rake tooth pile comprises an outer steel pipe and a lining steel pipe which is coaxially arranged in an inner hole of the outer steel pipe and can move relative to the length direction of the outer steel pipe. More than two groups of rake teeth which are uniformly distributed in a surrounding manner are arranged on the outer steel pipe and the lining steel pipe along the length direction; an outer pipe opening and an inner pipe opening are respectively formed in the pipe wall corresponding to each rake tooth; one end, close to the pile cap with the flange structure of the lining steel pipe, of one surface of each rake tooth with the sawtooth structure is in rotary pair connection with the outer steel pipe; before the steel rake tooth pile is driven, a tubular temporary fixing piece is arranged at the position, tightly attached to the pile cap, outside the lining steel pipe in a sleeving mode, each outer pipe opening in the outer steel pipe is restrained to be aligned with the corresponding inner pipe opening through the temporary fixing piece, and each rake tooth is contained in the corresponding outer pipe opening, the corresponding inner pipe opening and the lining steel pipe; the bottoms of the lining steel pipe and the outer steel pipe are flush. The bearing capacity of the pile foundation is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of pile foundations, and particularly to steel rake teeth piles and their design, manufacturing, and pile driving construction methods. Background Art

[0002] In many power transmission and transformation projects, pile foundations play a crucial bearing role.

[0003] However, when the existing pile foundations face large vertical pressures and lateral pressures in complex geological environments, when the designed bearing capacity is insufficient, problems such as settlement and inclination are likely to occur, affecting the overall safety and service life of the building. To increase the vertical bearing capacity of pile foundations, methods such as increasing the pile diameter, increasing the pile length, and post-grouting are usually adopted to increase the side friction resistance and tip resistance of the pile foundation to improve the vertical bearing capacity. However, this method increases the cost significantly, and it is difficult to effectively improve the bearing capacity of the pile foundation in cases where there are limitations on the pile diameter and pile length. Therefore, there is an urgent need for a technology and corresponding construction method that can effectively improve the vertical bearing capacity of pile foundations to improve this situation.

[0004] Currently, the bearing capacity of all friction piles mainly relies on the side friction resistance of the pile, and the side friction resistance mainly comes from the friction between the pile body and the soil. By improving the friction between the pile body and the soil, the bearing capacity of the pile body can be improved, such as improving the soil properties, pile side post-grouting technology, etc., but the improvement is limited.

[0005] Compared with the friction resistance, the cutting force can more effectively increase the resistance of the soil to the pile body. For the bamboo joint piles or other similar special-shaped piles that appear on the market, the resistance between the pile body and the soil is increased by setting a structure similar to bamboo joints. However, the bamboo joints exist from the beginning. During the pile pressing or driving process, the bamboo joints will cut the soil, prematurely destroying the close fit between the soil and the pile body, reducing the side friction resistance of the pile, and also unable to fully exert the cutting effect of the bamboo joints on the soil during subsequent use. Moreover, the cutting effect of the bamboo joint piles on the soil only stays at the conceptual level and cannot be calculated, so it cannot be accurately designed.

[0006] Therefore, how to ensure that during the pile driving process, the pile body is in close contact with the soil to fully exert the side friction resistance, and at the same time, during the later use, the side resistance can be increased by increasing the cutting of the pile body on the soil, and at the same time, it can be accurately calculated to ensure the rationality of the pile foundation bearing capacity design has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0007] In view of the above defects of the prior art, the present invention provides a steel rake tooth pile and its design, manufacturing, and pile driving construction method, with the aim of solving the existing technical difficulties, making the pile body closely fit the soil during the pile driving process like a conventional precast pile, ensuring the full exertion of the lateral friction resistance in the later stage. After the pile foundation is driven in, the rake teeth are pushed into the soil through the relative sliding of the inner and outer piles, ensuring that when the pile foundation exerts its bearing capacity, the rake teeth can cause cutting failure with the soil, and improving the vertical compressive or uplift bearing capacity of the pile foundation by increasing the cutting force of the rake teeth. At the construction site, only workers need to disassemble the temporary fixing parts, with simple operation and high speed.

[0008] To achieve the above object, the present invention discloses a steel rake tooth pile, which includes an outer steel pipe and an inner lining steel pipe coaxially arranged in the inner hole of the outer steel pipe and capable of moving relative to the outer steel pipe in the length direction.

[0009] The outer steel pipe and the inner lining steel pipe are provided with two or more groups of evenly distributed rake teeth along the length direction, and the pipe walls are respectively provided with outer pipe openings and inner pipe openings at the positions corresponding to each rake tooth.

[0010] Each rake tooth is a triangular plate structure with the longest side being a serrated structure.

[0011] Each outer pipe opening and the corresponding inner pipe opening are rectangles matching the serrated side of the corresponding rake tooth, and the length directions are all parallel to the axial directions of the outer steel pipe and the inner lining steel pipe.

[0012] One end of the inner lining steel pipe is provided with a pile cap in a flange structure.

[0013] One end of each rake tooth with the serrated side close to the pile cap is connected to the outer steel pipe with a revolute pair.

[0014] Before the steel rake tooth pile is driven in, a tubular temporary fixing part is sleeved at the position where the inner lining steel pipe is closely attached to the pile cap. By the temporary fixing part, each outer pipe opening on the outer steel pipe is constrained to be aligned with the corresponding inner pipe opening, so that each rake tooth is received in the corresponding outer pipe opening, the corresponding inner pipe opening, and the inner lining steel pipe.

[0015] After all the rake teeth are pushed out of the outer pipe openings by the inner lining steel pipe, the end of the inner lining steel pipe without the pile cap is still located inside the outer steel pipe.

[0016] Preferably, a rotary shaft perpendicular to the axial direction of the outer steel pipe is provided at the position of each outer pipe opening close to the pile cap; a barbed slot hole is provided at the position of each rake tooth corresponding to the corresponding rotary shaft, and the corresponding slot hole is hung on the corresponding rotary shaft to form the revolute pair with the outer steel pipe.

[0017] More preferably, each of the rotary shafts is a screw and is fixed to the outer steel pipe by welding.

[0018] More preferably, the pile cap is fixed to one end of the inner lining steel pipe by welding.

[0019] Preferably, each set of evenly distributed rake teeth includes 3 or 4 rake teeth; the distance between every two adjacent sets of rake teeth is 1 m ± 5%.

[0020] The present invention also provides a design method for a steel rake tooth pile, comprising the following steps:

[0021] Step A1: According to the vertical load transferred to the pile top in the upper structure design and the geological exploration report, obtain the standard value q of the skin friction of the pile, si the standard value q of the end bearing resistance of the pile, p preliminarily determine the pile diameter and pile length, and calculate the standard value Q of the vertical bearing capacity of a single pile;

[0022] Step A2: Determine the width, height and thickness of each rake tooth according to the preliminarily determined pile diameter, calculate the cutting area of each rake tooth, and then calculate the cutting resistance of each rake tooth according to the unit cutting specific resistance of the soil. Superimpose the cutting resistances of all the rake teeth and the standard value Q of the vertical bearing capacity of a single pile to obtain the standard value of the pile foundation bearing capacity;

[0023] Step A3: Check whether the standard value of the pile foundation bearing capacity meets the pile top load requirement; if the selected size does not meet the pile top load requirement, enlarge the pile diameter and re - execute Steps A1 to A3 until the pile top load requirement is met.

[0024] Preferably, the number of piles m is rounded up after magnifying the reaction force F of the upper structure design foundation divided by the standard value Q of the vertical bearing capacity of a single pile; the number of rake teeth n is rounded up after magnifying ((the reaction force F of the upper structure design foundation divided by the number of piles m - the standard value Q of the vertical bearing capacity of a single pile) divided by the cutting resistance F of each rake tooth). Z / the standard value Q of the vertical bearing capacity of a single pile and then rounding up; the number of rake teeth n is ((the reaction force F of the upper structure design foundation Z / the number of piles m - the standard value Q of the vertical bearing capacity of a single pile) / the cutting resistance F of each rake tooth) and then rounding up.

[0025] The present invention also provides a manufacturing method for a steel rake tooth pile, and the steps are as follows:

[0026] Step B1: Take the pipe diameter and wall thickness obtained from the design as the pipe diameter and wall thickness of the outer steel pipe, and then determine the pipe diameter and wall thickness of the inner lining steel pipe; wherein, the wall thickness of the inner lining steel pipe takes the same thickness as the outer steel pipe, and then determine the outer diameter of the inner lining steel pipe according to the gap size between the inner lining steel pipe and the outer steel pipe;

[0027] Step B2: Select the steel materials of the outer steel pipe, the inner lining steel pipe, the rake teeth and the pile cap according to the design requirements for processing;

[0028] Step B3: Open all the outer pipe openings in the outer steel pipe according to the size of each rake tooth;

[0029] Step B4: Weld screws in each outer pipe opening to form the corresponding rotary shaft;

[0030] Step B5: Open all the inner pipe openings in the inner steel pipe;

[0031] Step B6: Insert the inner steel pipe into the outer steel pipe. When all the inner pipe openings are aligned with all the outer pipe openings, form a revolute pair between all the rake teeth and the corresponding rotary shafts through the corresponding slot holes;

[0032] Step B7: Install the temporary fixing piece and weld the pile cap to restrict the inner steel pipe and the outer steel pipe from moving.

[0033] The present invention also provides a pile driving construction method for a steel rake tooth pile, and the steps are as follows:

[0034] Step C1: Use a pile driver to lift the steel rake tooth pile and lower it to align with the marked pile position;

[0035] Step C2: Start the pile driver and gradually drive the pile body into the ground by means of static pressure or hammering according to the predetermined pile driving standard;

[0036] Step C3: When the pile top reaches the first elevation, remove the temporary fixing piece, and only apply static pressure or hammering to the inner steel pipe, so that the elevation of the outer steel pipe relative to the ground remains unchanged, and relative sliding occurs between the inner steel pipe and the outer steel pipe;

[0037] The distance by which the first elevation is higher than the design elevation is the height of the temporary fixing piece + 100 mm ± 5%;

[0038] Step C4: When the top of the inner steel pipe is flush with the outer steel pipe, that is, when the pile cap is in contact with the outer steel pipe, push all the rake teeth from the inner steel pipe to the outside of the outer steel pipe, and all the rake teeth form the best cutting angle with the soil;

[0039] Step C5: After welding or mechanically connecting the periphery of the pile cap to the outer steel pipe, continue to apply static pressure or hammering to drive the pile body into the soil. When the pile top reaches the design elevation, the pile driving is completed.

[0040] Preferably, during the pile driving process, the verticality parameter of the steel rake tooth pile is monitored in real time, and if there is a deviation, it is adjusted in time.

[0041] Preferably, after the construction of the steel rake tooth pile driving is completed, the bearing capacity and integrity of the pile are detected to ensure that they meet the engineering requirements; then, the connection construction of the pile cap and the bearing platform structure is carried out.

[0042] Advantages of the present invention:

[0043] In the present invention, the steel rake tooth pile is more closely combined with the surrounding soil. By the method of positioning the rake teeth after the pile body is driven, it can not only effectively ensure the exertion of the cutting force of the rake teeth, but also ensure the close fit of the pile body and the soil so as to continue to effectively exert the side friction resistance of the pile. At the same time, the cutting resistance of the rake teeth can be accurately calculated, providing a design basis for the design. Moreover, it is simple to manufacture and convenient and fast to construct, and can effectively improve the bearing capacity of the pile foundation in projects with limited pile diameter and pile length, and has good application prospects.

[0044] The following will further illustrate the concept, specific structure and technical effects generated by the present invention with reference to the drawings, so as to fully understand the purpose, features and effects of the present invention. Brief description of the drawings

[0045] Figure 1 The structural schematic diagram before pile driving in an embodiment of the present invention is shown.

[0046] Figure 2 The structural schematic diagram after pile driving in an embodiment of the present invention is shown.

[0047] Figure 3 The sectional structural schematic diagram in the A-A direction of the embodiment with 4 circumferential rake teeth of the present invention is shown in Figure 1 the A-A direction.

[0048] Figure 4 The sectional structural schematic diagram in the A-A direction of the embodiment with 3 circumferential rake teeth of the present invention is shown in Figure 1 the A-A direction.

[0049] Figure 5 The sectional structural schematic diagram in the B-B direction of the embodiment with 4 circumferential rake teeth of the present invention is shown in Figure 2 the B-B direction.

[0050] Figure 6 The sectional structural schematic diagram in the B-B direction of the embodiment with 3 circumferential rake teeth of the present invention is shown in Figure 2 the B-B direction.

[0051] Figure 7 The schematic diagram of the rake tooth structure in an embodiment of the present invention is shown.

[0052] Wherein, 1. Outer steel pipe, 101. Outer pipe opening, 102. Rotary shaft, 2. Inner lining steel pipe, 201. Inner pipe opening, 202. Pile cap, 3. Rake tooth, 301. Slot hole, 4. Temporary fixing piece. Detailed implementation manners

[0053] Embodiment

[0054] As Figures 1 to 7 shown, a steel rake tooth pile; characterized in that it includes an outer steel pipe 1 and an inner lining steel pipe 2 coaxially arranged in the inner hole of the outer steel pipe 1 and capable of moving relative to the outer steel pipe 1 in the length direction;

[0055] The outer steel pipe 1 and the inner lining steel pipe 2 are provided with two or more groups of evenly distributed rake teeth 3 along the length direction, and the pipe walls are respectively provided with outer pipe openings 101 and inner pipe openings 201 corresponding to each rake tooth 3;

[0056] Each rake tooth 3 is a triangular plate structure with the longest side being a serrated structure;

[0057] Each outer pipe opening 101 and the corresponding inner pipe opening 201 are rectangles matching the serrated surface of the corresponding rake tooth 3, and the length directions are all parallel to the axial directions of the outer steel pipe 1 and the inner lining steel pipe 2;

[0058] One end of the inner lining steel pipe 2 is provided with a pile cap 202 in a flange structure;

[0059] One end of each rake tooth 3 with a serrated structure is rotatably connected to the outer steel pipe near the pile cap 202;

[0060] Before the steel rake tooth pile is driven, a tubular temporary fixing member 4 is sleeved at the position close to the pile cap 202 outside the inner lining steel pipe 2. By the temporary fixing member 4, each outer pipe opening 101 on the outer steel pipe 1 is constrained to be aligned with the corresponding inner pipe opening 201, so that each rake tooth 3 is received in the corresponding outer pipe opening 101, the corresponding inner pipe opening 201, and the inner lining steel pipe 2;

[0061] After all the rake teeth 3 are pushed out of the outer pipe openings 101 by the inner lining steel pipe 2, the end of the inner lining steel pipe 2 without the pile cap 202 is still located inside the outer steel pipe 1.

[0062] In the present invention, by adding an inner lining steel pipe 2 inside the outer steel pipe 1 and arranging a rake tooth 3 structure on the outer steel pipe 1, after the pile foundation is in place, the rake teeth 3 are pushed into the soil by the relative sliding of the outer steel pipe 1 and the inner lining steel pipe 2, so that a cutting action can occur between the rake teeth 3 and the soil body, and the vertical compressive or uplift bearing capacity of the pile foundation is improved by increasing the cutting force of the rake teeth 3.

[0063] During the construction site, only workers need to disassemble the temporary fixing member, the operation is simple and fast, and it can effectively improve the bearing capacity of the pile foundation under the condition of limited pile diameter and pile length.

[0064] Among them, the outer steel pipe 1 and the inner lining steel pipe 2 restrict their positions relative to each other through the temporary fixing member 4. The connection method of the temporary fixing member 4 can be welding connection or mechanical connection. The mechanical connection means that bolt holes are reserved at corresponding positions on the temporary fixing member 4, the outer steel pipe 1, and the pile cap 202, and they are connected together by bolts. Since the connection method is common and relatively easy to implement, it is not the specific content of the present invention, and different methods can be adopted according to the actual engineering needs. It is only used for temporary fixation before and during piling.

[0065] In some embodiments, a rotating shaft 102 perpendicular to the axis of the outer steel pipe 1 in space is provided at a position where each outer pipe opening 101 is close to the pile cap 202; a barbed slot 301 is provided at a position corresponding to each rotating shaft 102 of each rake tooth 3, and the corresponding slot 301 is hung on the corresponding rotating shaft 102 to form a revolute pair with the outer steel pipe 1.

[0066] In some embodiments, each rotating shaft 102 is a screw and is fixed to the outer steel pipe 1 by welding.

[0067] In some embodiments, the pile cap 202 is fixed to one end of the inner lining steel pipe 2 by welding.

[0068] In some embodiments, each set of evenly distributed rake teeth 3 includes 3 or 4 rake teeth 3; the distance between every two adjacent rake teeth 3 is 1 m ± 5%.

[0069] The present invention also provides a design method for a steel rake tooth pile, including the following steps:

[0070] Step A1: According to the vertical load transmitted to the pile top in the upper structure design and the geological exploration report, obtain the standard value q of the side friction resistance of the pile based on the soil properties in the geological exploration report si , the standard value q of the end resistance of the pile p , preliminarily determine the pile diameter and pile length, and calculate the standard value Q of the vertical bearing capacity of a single pile;

[0071] Step A2: Determine the width, height, and thickness of each rake tooth 3 according to the preliminarily determined pile diameter, calculate the cutting area of each rake tooth 3, and then calculate the cutting resistance of each rake tooth 3 according to the unit cutting specific resistance of the soil. Add the cutting resistances of all rake teeth 3 and the standard value Q of the vertical bearing capacity of a single pile to obtain the standard value of the pile foundation bearing capacity;

[0072] Step A3: Check whether the standard value of the pile foundation bearing capacity meets the requirements of the pile top load; if the selected size does not meet the requirements of the pile top load, enlarge the pile diameter and re-execute Steps A1 to A3 until the requirements of the pile top load are met.

[0073] If the vertical load transferred to the pile top in the upper structure design is 250 kN, according to the geological exploration report, the soil layer is uniform and unique, all of which are silty clay. The standard value of the skin friction of the pile side q si =15 kPa, and the standard value of the end resistance of the pile q p =0. The pile diameter is limited within 500 mm, and the pile length is limited within 10 m. Initially, a pipe pile with a diameter of 400 mm is selected for trial calculation. The pile length is limited to 10 m. Then, according to the "Technical Code for Building Pile Foundations", the remaining parameters including the wall thickness are obtained, and according to Article 5.3.5 thereof, the standard value of the vertical bearing capacity of a single pile Q = u∑q si l i +q p A p =3.14 * 0.4 * 15 * 10 + 0 = 188.4 kN.

[0074] Considering the adoption of drag tooth piles, the drag tooth piles are steel pipe piles. Initially, a steel pipe with a diameter of 400 mm is selected, and the size of each drag tooth is selected as 200 mm wide * 270 mm high * 60 mm thick. Then, the cutting area A of each drag tooth = 200 - 10 * 60 = 11400 mm 2 , according to the soil unit cutting specific resistance k of the soil, k can be taken as 200 kPa, and the cutting resistance F of each drag tooth = kA = 200 * 0.0114 = 2.28 kN. Arranged in a horizontal plane with 4 in a group, and arranged 1 group every 1 m along the 10 m length of the pile. At most 9 groups can be arranged, that is, at most 36 can be arranged. Then, the standard value of the pile foundation bearing capacity is Q + nF = 188.4 + 36 * 2.28 = 270.48 kN > 250 kN. Therefore, the bearing capacity of the drag tooth pile with a diameter of 400 can meet the requirements.

[0075] In some embodiments, the number of piles m is rounded up after magnifying the foundation reaction force F of the upper structure design Z / the standard value of the vertical bearing capacity of a single pile Q; the number of drag teeth 3 n is rounded up after magnifying (the foundation reaction force F of the upper structure design Z / the number of piles m - the standard value of the vertical bearing capacity of a single pile Q) / the cutting resistance F of each drag tooth.

[0076] For example, in a certain place, the foundation reaction force F of the upper structure design Z =1000 kN, and other conditions are the same as the above conditions. When a conventional pipe pile with a diameter of 400 mm is selected, the number of piles m = 1000 / 188.4 = 5.3, and 6 piles are taken. When the selection is limited to a diameter of 400 and the number of piles is required not to exceed 5, drag tooth piles can be used. The number of drag teeth n required for each pile = (F Z / m - Q / ) F = (1000 / 5 - 188.4) / 2.28 = 5.1, and 6 can be taken, that is, only 6 drag teeth need to be set for each drag tooth pile to meet the requirements.

[0077] The present invention also provides a manufacturing method for steel rake teeth piles, and the steps are as follows:

[0078] Step B1: Take the pipe diameter and wall thickness obtained from the design as the pipe diameter and wall thickness of the outer steel pipe 1, and then determine the pipe diameter and wall thickness of the inner lining steel pipe 2 according to the pipe diameter and wall thickness of the outer steel pipe 1; wherein, the wall thickness of the inner lining steel pipe 2 takes the same thickness as the outer steel pipe 1, and then determine the outer diameter of the inner lining steel pipe 2 according to the gap size between the inner lining steel pipe 2 and the outer steel pipe 1;

[0079] Step B2: Select the steel materials for the outer steel pipe 1, the inner lining steel pipe 2, the rake teeth 3 and the pile cap 4 according to the design requirements for processing;

[0080] Step B3: Open all the outer pipe openings 101 on the outer steel pipe 1 according to the size of each rake tooth 3;

[0081] Step B4: Weld screws in each outer pipe opening 101 to form corresponding rotating shafts 102;

[0082] Step B5: Open all the inner pipe openings 201 on the inner lining steel pipe 2;

[0083] Step B6: Insert the inner lining steel pipe 2 into the outer steel pipe 1. When all the inner pipe openings 201 are aligned with all the outer pipe openings 101, form a revolute pair between all the rake teeth 3 and the corresponding rotating shafts 102 through the corresponding slot holes 301;

[0084] Step B7: Install the temporary fixing piece 4 and weld the pile cap 4 to restrict the inner lining steel pipe 2 and the outer steel pipe 1 from moving.

[0085] In practical applications, for example, for a rake teeth pile with a diameter of 400 mm and a pile length of 10 m, 4 are arranged in a group according to the horizontal plane layout, and 1 group is arranged every 1 m along the 10 m length of the pile, with a total of 9 groups arranged. The thickness of the outer steel pipe is taken as 10 mm, and a gap of 5 mm is reserved between the outer diameter of the inner lining steel pipe and the inner diameter of the outer steel pipe, so the outer diameter of the inner lining steel pipe is 370 mm, and the wall thickness of the inner lining steel pipe is also taken as 10 mm. The materials of the steel pipe pile, the rake teeth 3, the pile cap, etc. are all Q235B grade steel. An outer pipe opening 101 is set vertically every 1 m on the outer side of the outer steel pipe, and the opening size is set as 330 mm * 65 mm according to the size of the rake teeth 3 to ensure that the rake teeth 3 can rotate freely in the hole. Four openings are set at the same height at the positions corresponding to 4 rake teeth 3 on the plane, such as Figure 3As shown in the figure. A screw is welded in the opening 101 of the outer pipe. The diameter of the screw needs to match the slot 301 of the rake tooth 3. For example, if the diameter of the screw is 8 mm, the diameter of the slot 301 can be taken as 9 mm. The maximum dimension of the outer contour of the rake tooth 3 is a triangular prism with a width of 200 mm, a height of 270 mm, and a thickness of 60 mm. A tooth-shaped structure is provided on the hypotenuse. This structure is to improve the soil cutting effect of the rake tooth 3 during the uplift resistance of the pile foundation. Although not discussed in this case, an uplift pile can also be used. A slot 301 is provided at the end where it is fixed to the screw. The slot 301 is wider on the outside and narrower on the inside, similar to a flared shape. The dimension of the narrowest part on the inside is slightly smaller than the diameter of the screw. When installing, the rake tooth 3 needs to be pressed firmly to connect with the screw, and then the rake tooth 3 can be prevented from falling off, such as Figure 7 As shown.

[0086] After the outer steel pipe is processed, the inner lining steel pipe is processed. The top of the inner lining steel pipe 2 should first be higher than the outer steel pipe by the height of an opening size. At the same time, the bottom needs to ensure that it is not lower than the bottom of the outer steel pipe after sliding. Then the length of the inner lining steel pipe 2 can be taken as 9.6 m. Similarly, an inner pipe opening 201 is provided on the steel pipe every 1 m, and the opening size is also 330 mm * 65 mm. When installing the inner lining steel pipe 2, it is slowly inserted from the top of the outer steel pipe 1. Stop when the top is 330 mm higher than the top of the steel pipe 1. At this time, the outer pipe opening 101 and the inner pipe opening 201 on the outer steel pipe and the inner lining steel pipe should be at the same height. Rotate the inner lining steel pipe to align the outer pipe opening 101 and the inner pipe opening 201 on the plane, and place the rake tooth 3 inside, such as Figure 1 As shown. Then install the temporary fixing piece 4. The height of the temporary fixing piece is the same as the height of the outer pipe opening 101, which is 330 mm. A fixing pile cap is welded to the top of the inner lining steel pipe 2. The pile cap is a steel plate with a diameter of 400 mm and a thickness of 20 mm, and is fully welded to the inner lining steel pipe 2 in a circle. At this time, the production is completed. Then, the quality of the pile body is detected to ensure that it meets the design strength and other standards.

[0087] The present invention also provides a pile driving construction method for a steel rake tooth pile, and the steps are as follows:

[0088] Step C1: Use a pile driver to lift the steel rake tooth pile and lower it to align with the marked pile position;

[0089] Step C2: Start the pile driver and gradually drive the pile body into the ground by static pressure or hammering according to the predetermined pile driving standard;

[0090] Step C3: When the pile top reaches the first elevation, remove the temporary fixing piece 4, and only perform static pressure or hammering on the inner lining steel pipe 2 to keep the elevation of the outer steel pipe 1 relative to the ground unchanged and cause the inner lining steel pipe 2 to slide relative to the outer steel pipe 1;

[0091] The distance that the first elevation is higher than the design elevation is the height of the temporary fixing piece 4 + 100 mm ± 5%;

[0092] Step C4: When the top of the inner steel pipe 2 is flush with the outer steel pipe 1, that is, when the pile cap 202 is in contact with the outer steel pipe 1, push all the harrow teeth 3 from the inner steel pipe 2 to the outside of the outer steel pipe 1, and all the harrow teeth 3 form the best cutting angle with the soil body;

[0093] Step C5: After welding or mechanically connecting the periphery of the pile cap 202 to the outer steel pipe 1, continue to statically press or hammer the pile body into the soil. When the pile top reaches the design elevation, the pile driving is completed.

[0094] In practical applications, use a suitable pile driver to lift the fabricated harrow tooth pile, align it with the marked pile position, slowly lower it, start the pile driver, and gradually drive the pile body into the ground in a suitable manner such as static pressing or hammering according to the predetermined pile sinking standard. When the pile top reaches the first elevation, the first elevation is higher than the design elevation by a distance of the height of the temporary fixing member 4 + 100 mm. At this time, remove the temporary fixing members 4 of the inner and outer steel pipes, and only statically press or hammer the inner steel pipe 2. At this time, the elevation of the outer steel pipe relative to the ground remains unchanged, and the inner steel pipe 2 slides relative to the outer steel pipe. When the top of the inner steel pipe 2 is flush with the outer steel pipe, that is, when the pile cap 202 is in contact with the outer steel pipe, at this time all the harrow teeth are also pushed to the outside by the inner steel pipe 2, as Figure 2 shown, the harrow teeth form the best cutting angle with the soil body. Weld or mechanically connect the periphery of the pile cap 202, and continue to statically press or hammer the pile body into the soil by 100 mm. When the pile top reaches the design elevation, the pile driving is completed.

[0095] In some embodiments, during the pile sinking process, the verticality parameter of the steel harrow tooth pile is monitored in real time, and if there is a deviation, it is adjusted in time.

[0096] In some embodiments, after the construction of the steel harrow tooth pile sinking is completed, the bearing capacity and integrity of the pile are detected to ensure that they meet the engineering requirements; then, the connection construction between the pile cap 202 and the pile cap structure is carried out.

[0097] The preferred specific embodiments of the present invention have been described in detail above. It should be understood that those of ordinary skill in the art can make many modifications and variations based on the concept of the present invention without creative labor. Therefore, all technical solutions that can be obtained by those skilled in the art in the technical field of the present invention based on the concept of the present invention through logical analysis, reasoning, or limited experiments on the basis of the prior art should be within the protection scope determined by the claims.

Claims

1. Steel rake pile; characterized in that, It comprises an outer steel pipe (1), and an inner lining steel pipe (2) coaxially arranged in the inner hole of the outer steel pipe (1) and capable of moving relative to the length direction of the outer steel pipe (1); The outer steel pipe (1) and the inner lining steel pipe (2) are provided with more than two groups of rake teeth (3) uniformly distributed around the pipe along the length direction, and the pipe wall is provided with an outer pipe opening (101) and an inner pipe opening (201) respectively at the position corresponding to each rake tooth (3); Each of the rake teeth (3) is a triangular plate structure with the longest side being a sawtooth structure; Each of the outer tube openings (101) and the corresponding inner tube openings (201) are rectangular and match the sawtooth structure of the corresponding rake teeth (3), and the length direction is parallel to the axial direction of the outer steel tube (1) and the inner lining steel tube (2); A pile cap (202) having a flange structure is provided at one end of the inner lining steel pipe (2); A side of each rake tooth (3) having a sawtooth structure is connected to the outer steel pipe (1) in a rotary pair at one end close to the pile cap (202); Before the steel rake tooth pile is driven in, a tubular temporary fixing member (4) is sleeved on the outer side of the inner lining steel pipe (2) close to the pile cap (202), and each outer pipe opening (101) on the outer steel pipe (1) is constrained by the temporary fixing member (4) to be aligned with the corresponding inner pipe opening (201), so that each rake tooth (3) is accommodated in the corresponding outer pipe opening (101), the corresponding inner pipe opening (201), and the inner lining steel pipe (2); After all the rake teeth (3) are pushed out of the outer tube opening (101) by the inner lining steel tube (2), the end of the inner lining steel tube (2) without the pile cap (202) is still located in the outer steel tube (1).

2. The steel rake pile according to claim 1, characterized in that: Each of the outer tube openings (101) is provided with a rotation axis (102) which is spatially perpendicular to the axial direction of the outer steel tube (1) at a position close to the pile cap (202); each of the rake teeth (3) is provided with a barbed slot (301) at a position corresponding to the corresponding rotation axis (102), and the rotation pair is formed with the outer steel tube (1) by hanging the corresponding slot (301) on the corresponding rotation axis (102).

3. The steel rake pile according to claim 2, characterized in that: Each of the rotating shafts (102) is a screw and is fixed to the outer steel pipe (1) by welding; the pile cap (202) is fixed to one end of the inner lining steel pipe (2) by welding.

4. The steel rake pile according to claim 1, characterized in that: Each group of the rake teeth (3) uniformly distributed around each other comprises three or four rake teeth (3); and the interval between each two adjacent groups of the rake teeth (3) is 1 meter ±5%.

5. The design method of steel rake pile according to claim 1, characterized in that: The steps include: Step A1: Obtain the standard value of pile side friction resistance q according to the vertical load transmitted to the pile top in the superstructure design, the geological survey report, whether the soil layer is uniform and unique, and the properties of the soil layer. si , Standard value of pile end resistance q p 1. Preliminarily determine the pile diameter and pile length, and calculate the standard value Q of the vertical bearing capacity of a single pile; Step A2, determining the width, height and thickness of each rake tooth (3) according to the initially determined pile diameter, and calculating the cutting area of ​​each rake tooth (3), and then calculating the cutting resistance of each rake tooth (3) according to the unit cutting resistance of the soil, superimposing the cutting resistance of all the rake teeth (3) and the standard value Q of the vertical bearing capacity of the single pile, and obtaining the standard value of the pile foundation bearing capacity; Step A3, verify whether the standard value of the pile foundation bearing capacity meets the pile top load requirement; if the selected size does not meet the pile top load requirement, enlarge the pile diameter and re-execute steps A1 to A3 until the pile top load requirement is met.

6. The design method of steel rake pile according to claim 5, characterized in that: The number of piles m is the design foundation reaction force F of the superstructure Z / The standard value Q of the vertical bearing capacity of the single pile is enlarged and rounded; the number n of the rake teeth (3) is (the design foundation reaction force F of the upper structure Z / number of piles m-standard value of vertical bearing capacity of the single pile Q) / cutting resistance F of each rake tooth and then enlarge and round up.

7. The method for manufacturing a steel rake tooth pile according to claim 1, characterized in that: Here are the steps: Step B1, using the designed pipe diameter and wall thickness as the pipe diameter and wall thickness of the outer steel pipe (1), and then determining the pipe diameter and wall thickness of the inner lining steel pipe (2) according to the pipe diameter and wall thickness of the outer steel pipe (1); wherein the wall thickness of the inner lining steel pipe (2) is the same as the thickness of the outer steel pipe (1), and then determining the outer diameter of the inner lining steel pipe (2) according to the gap size between the inner lining steel pipe (2) and the outer steel pipe (1); Step B2, selecting steel materials of the outer steel pipe (1), the inner lining steel pipe (2), the rake teeth (3) and the pile cap (4) for processing according to design requirements; Step B3, opening all the outer tube openings (101) in the outer steel tube (1) according to the size of each rake tooth (3); Step B4, welding a screw in each of the outer tube openings (101) to form the corresponding rotary shaft (102); Step B5, opening all the inner tube openings (201) in the inner lining steel tube (2); Step B6, inserting the inner lining steel pipe (2) into the outer steel pipe (1), and when all the inner pipe openings (201) are aligned with all the outer pipe openings (101), all the rake teeth (3) are connected to the corresponding rotating shafts (102) through the corresponding slots (301) to form a rotating pair; Step B7: Install the temporary fixing member (4) and weld the pile cap (4) to constrain the inner lining steel pipe (2) and the outer steel pipe (1) to prevent them from moving.

8. The method for constructing a steel rake tooth pile according to claim 1, characterized in that: Here are the steps: Step C1, using a pile driver to lift the steel rake pile, and lower it to the marked pile position; Step C2, starting the pile driver, and gradually driving the pile body into the ground by static pressure or hammering according to a predetermined pile sinking standard; Step C3, when the pile top reaches the first step elevation, remove the temporary fixing member (4), and only apply static pressure or hammering to the inner lining steel pipe (2), so that the elevation of the outer steel pipe (1) relative to the ground remains unchanged, and the inner lining steel pipe (2) and the outer steel pipe (1) slide relative to each other; The distance by which the first step elevation is higher than the design elevation is the height of the temporary fixing member (4) + 100 mm ± 5%; Step C4, when the top of the inner lining steel pipe (2) is flush with the outer steel pipe (1), that is, the pile cap (202) is in contact with the outer steel pipe (1), all the rake teeth (3) are pushed from the inner lining steel pipe (2) to the outside of the outer steel pipe (1), and all the rake teeth (3) form an optimal cutting angle with the soil; Step C5: After the pile cap (202) is welded or mechanically connected to the outer steel pipe (1) on all sides, the pile body is continuously statically pressed or hammered into the soil. When the pile top reaches the designed elevation, the piling is completed.

9. The method for constructing a steel rake tooth pile according to claim 8, characterized in that: During the pile sinking process, the verticality parameters of the steel rake pile are monitored in real time, and if any deviation occurs, timely adjustments are made.

10. The method for constructing a steel rake tooth pile according to claim 8, characterized in that: After the steel rake tooth pile sinking construction is completed, the bearing capacity and integrity of the pile are tested to ensure that it meets the engineering requirements; then, the pile cap (202) is connected to the foundation structure.

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