Inclined steel pipe pile support with pit bottom pressure reduction and bidirectional grouting functions

Abstract

The utility model discloses an inclined steel pipe pile support with pit bottom pressure reduction and bidirectional grouting functions, and belongs to the field of building construction. The inclined steel pipe pile support sequentially comprises a top conventional section, a middle grouting section, a bottom pressure reduction section and an end grouting head from top to bottom. And a plurality of grouting pipes are uniformly fixed on the inner sides of the top conventional section, the middle grouting section and the bottom pressure reducing section in the circumferential direction. A plurality of lateral grouting holes used for lateral soil reinforcement are formed in the side wall of the middle grouting section at intervals in the axial direction of the lateral grouting pipe; a plurality of filter holes for releasing the pressure of the confined water are formed in the side wall of the bottom pressure reducing section. The end grouting head is of a conical structure for reducing resistance; and an end grouting hole communicated with the end grouting pipe is formed in the end grouting head. The inclined steel pipe pile support has the functions of pit bottom pressure reduction and two-way grouting, and the number of pressure reduction wells in a pit can be remarkably reduced. In addition, after large-scale pouring of the bottom plate is completed, the inclined steel pipe pile support can be pulled upwards to be recycled.

Description

Technical Field

[0001] The utility model belongs to the field of building construction, and in particular relates to an inclined steel pipe pile support with pit bottom pressure relief and bidirectional grouting functions. Background Art

[0002] The most common form of oblique composite pile support on the market is "steel lattice pile + mixing reinforcement". This method uses an improved high-pressure jet grouting machine to reinforce the soil in advance and drill holes, and then insert the prefabricated steel lattice pile obliquely into the hole. After cement and other cementitious materials solidify, they will form lateral and end reinforcements around and below the steel lattice pile, thereby improving the bearing capacity of the steel lattice pile.

[0003] In recent years, sudden water outburst accidents have occurred frequently in foundation pits. When the earthwork is excavated to the bottom, if the pressure of the confined water at the bottom of the pit exceeds the gravity of the covering soil, a sudden water outburst accident may occur. In most areas along the southeast coast, the confined water layer is deep, and the top burial depth is usually more than 30m. Therefore, for foundation pits with an excavation depth of no more than 15 meters, the gravity of the covering soil at the bottom of the pit is often greater than the pressure of the confined water, and the risk of sudden water outburst accidents is relatively low. However, in areas such as Zhuji, Zhejiang, the confined water layer is relatively shallow, and the top burial depth is only about 15 meters. For foundation pit projects with an excavation depth of about 10 meters, the confined water layer is 5 meters below the bottom of the pit. In this case, once the earthwork is excavated to the bottom of the pit, the thickness of the covering soil is relatively thin, and there is a risk of sudden water outburst. In order to prevent the occurrence of sudden water outburst accidents, a pressure relief well must be set up in the pit to release part of the pressure of the confined water. The pressure relief well is generally made of steel pipes, and filter holes are opened within the range of the confined water layer. During the earthwork excavation process, the upper section of the pressure relief well must not be cut off or damaged. In addition, the relief well needs to be connected and fixed to the horizontal internal supports of each layer to prevent it from overturning.

[0004] The existing method of combining inclined composite pile support with pressure relief wells in the pit has the following shortcomings: (1) The mixing and reinforcement takes a long time, which affects the construction period, and the cementitious materials used are more, which increases the cost; (2) The mixing and reinforcement is usually carried out in advance. If there is a risk in the foundation pit during the earthwork excavation, the strength of the reinforced body that has been formed cannot be further strengthened; (3) Steel lattice piles are difficult to reuse, resulting in a large one-time investment; (4) The pressure relief wells in the pit need to be set up separately. For foundation pits with larger plane areas, the number of pressure relief wells in the pit is large, and the cost is high; For foundation pits supported by inclined composite piles, due to the lack of horizontal support, it is difficult to find a suitable connection and fixing point for the pressure relief wells, and there is a risk of overturning during use; (5) The pressure relief wells in the pit are usually made of steel pipes with an outer diameter of 273mm and a wall thickness of 4mm. They are difficult to protect during earthwork excavation and are easily damaged once they are hit by mechanical equipment. If the number of pressure relief wells is insufficient, additional ones need to be added, which further increases the cost. Therefore, it is urgent to develop an inclined steel pipe pile support with pit bottom pressure relief and two-way grouting functions. Utility Model Content

[0005] The utility model aims to solve the deficiencies in the prior art and provide an inclined steel pipe pile support with pit bottom pressure relief and bidirectional grouting functions.

[0006] The specific technical solutions adopted by this utility model are as follows:

[0007] The utility model provides an inclined steel pipe pile support with pit bottom pressure relief and bidirectional grouting functions. The inclined steel pipe pile support is arranged in an excavated foundation pit, and comprises a top conventional section, a middle grouting section, a bottom pressure relief section and an end grouting head from top to bottom; the top of the top conventional section is connected to the crown beam at the top of the foundation pit surrounding support structure through a reinforcing pier;

[0008] The top conventional section, the middle grouting section and the bottom decompression section are hollow structures that are connected internally, and a number of grouting pipes are evenly fixed along the circumferential direction on the inner side. The grouting pipes are divided into lateral grouting pipes for lateral soil reinforcement in the diving layer and end grouting pipes for end soil reinforcement in the confined water layer; a force transfer plate is fixed to the top outer wall of the top conventional section, and a reinforcement pier is cast outside the force transfer plate; through the force transfer plate and the reinforcement pier, the oblique steel pipe pile support is connected with the crown beam and the support pile to form an overall force system;

[0009] On the side wall of the middle grouting section, a plurality of lateral grouting holes for lateral soil reinforcement are arranged at intervals along the axial direction of the lateral grouting pipe; on the side wall of the bottom pressure relief section, a plurality of filter holes for releasing pressurized water pressure are arranged; the filter holes are evenly distributed in the axial and circumferential directions of the side wall of the bottom pressure relief section, and the positions of the filter holes are arranged away from the end grouting pipe to avoid leakage; the end grouting head is a conical structure for reducing resistance; the end grouting head is provided with an end grouting hole connected with the end grouting pipe.

[0010] Preferably, the top conventional section, the middle grouting section and the bottom pressure relief section are φ630×14 steel pipe piles.

[0011] Preferably, the grouting pipes are all made of φ48×3 steel pipes.

[0012] Preferably, the end grouting head adopts a conical cross pile tip and is welded into a whole with a 14 mm thick steel plate.

[0013] Preferably, the diameter of the lateral grouting hole is 15-20 mm; the center distance between the coaxial lateral grouting holes opened on the lateral grouting pipe is 150-250 mm; and the diameter of the filter hole is 8-12 mm.

[0014] Preferably, four grouting pipes are uniformly welded along the circumferential direction on the inner sides of the top conventional section, the middle grouting section and the bottom pressure relief section.

[0015] Preferably, a nylon net is arranged at the periphery of the bottom pressure relief section to prevent soil particles in the pressurized water layer from entering the interior of the inclined steel pipe pile support; a wire mesh is fixed outside the nylon net.

[0016] Preferably, the aperture of the nylon mesh is 60-80 meshes, and the aperture of the wire mesh is 5-10 meshes.

[0017] Preferably, the force transfer plate is made of 14 mm thick double-jointed steel plate, and the outer diameter of the force transfer plate is 1500 mm.

[0018] Preferably, the force transmission plate and the top outer wall of the top conventional section are fixed by welding.

[0019] Compared with the prior art, the utility model has the following beneficial effects:

[0020] (1) The inclined steel pipe pile support provided by the utility model does not require the soil to be reinforced in advance. The two-way grouting on the pile side and pile end can be carried out at a later stage. The reinforcement volume is significantly reduced compared with the traditional method, which is conducive to shortening the construction period and effectively reducing the construction cost.

[0021] (2) The inclined steel pipe pile support provided by the utility model has the functions of pit bottom pressure relief and bidirectional grouting, so the number of pressure relief wells in the pit can be significantly reduced. In particular, for foundation pits with smaller areas, there is no need to set up additional pressure relief wells, which further reduces costs. In addition, the safety hazards caused by the difficulty in connecting and fixing the pressure relief wells in the inclined composite pile foundation pit are avoided.

[0022] (3) During the excavation process, if a dangerous situation occurs in the foundation pit, the strength of the lateral or end reinforcement bodies can be specifically improved by re-grouting the inclined steel pipe pile supports to enhance the emergency response capabilities.

[0023] (4) For the inclined steel pipe pile supports that do not need to be retained, they can be pulled out as a whole and recycled after the large-scale pouring of the base plate is completed. This not only saves resources but also reduces project costs.

[0024] (5) The inclined steel pipe pile support adopted by the utility model has an outer diameter of 630mm and a wall thickness of 14mm. It has the function of pit bottom pressure relief. It is more rigid than the traditional pressure relief well with an outer diameter of 273mm and a wall thickness of 4mm. It is not easy to be damaged during the excavation process, which helps to ensure the continuity of the pressure relief operation and reduce the additional costs incurred by the well repair. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the oblique steel pipe pile support installation provided in this embodiment;

[0026] Figure 2 for Figure 1 Sectional view at AA;

[0027] Figure 3 for Figure 1 Cross-section at the middle BB;

[0028] Figure 4 for Figure 1 Cross-section at mid-CC;

[0029] Figure 5 for Figure 1 Sectional view at DD;

[0030] Figure 6 A schematic diagram of a pile end grouting head provided in this embodiment;

[0031] Figure 7 for Figure 1 Sectional view at EE;

[0032] Figure 8 for Figure 1 Cross-section at FF;

[0033] Fig. 9 This is a schematic diagram of the pressed-in oblique steel pipe pile support and grouting in the embodiment;

[0034] Fig.10 It is a schematic diagram of the elevation of the earth excavation to the bottom surface of the reinforcement pier in the embodiment;

[0035] Fig.11 It is a schematic diagram of strengthening pier construction in the embodiment;

[0036] Fig.12 This is a schematic diagram of the elevation of the earth excavation to the bottom surface of the foundation in the embodiment;

[0037] Fig.13 Schematic diagram of the construction of the outer foundation and the removal of the strengthening piers in order to avoid retaining the inclined steel pipe pile support;

[0038] Fig.14 In order to avoid the need to retain the inclined steel pipe pile support during construction, the schematic diagram of the upward pulling inclined steel pipe pile support is shown;

[0039] Fig.15 In order to avoid retaining the oblique steel pipe pile support construction, the remaining foundation construction diagram is shown;

[0040] Fig.16 In order to retain some inclined steel pipe piles to support the construction, the construction diagram of the foundation part is shown;

[0041] Fig.17 In order to keep part of the inclined steel pipe pile support during construction, the schematic diagram of the inclined steel pipe pile support is cut off;

[0042] Fig.18 In order to retain some inclined steel pipe piles to support the construction, the schematic diagram of the blocking construction is shown;

[0043] In the figure: top conventional section 1, middle grouting section 2, bottom pressure relief section 3, end grouting head 4, lateral grouting pipe 101, lateral grouting hole 201, filter hole 301, end grouting pipe 302, end grouting hole 401, force transfer plate 5, concrete 6, crown beam 7, reinforced pier 8, precipitation well 9, three-axis cement mixing pile 10, bored pile 11, phreatic layer 12, pressure water layer 13, lateral reinforcement body 14, end reinforcement body 15, water stop plate 16. DETAILED DESCRIPTION

[0044] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model. Therefore, the utility model is not limited by the specific embodiments disclosed below. The technical features in each embodiment of the utility model can be combined accordingly without conflicting with each other.

[0045] like Figure 1 As shown, in a preferred embodiment of the utility model, an inclined steel pipe pile support with pit bottom pressure relief and bidirectional grouting functions is provided. The inclined steel pipe pile support is arranged in the foundation pit to be excavated, and from top to bottom are the top conventional section 1, the middle grouting section 2, the bottom pressure relief section 3 and the end grouting head 4. The top conventional section 1, the middle grouting section 2 and the bottom pressure relief section 3 can adopt φ630×14 steel pipe piles, that is, the outer diameter is 630mm and the wall thickness is 14mm. Compared with the traditional pressure relief well with an outer diameter of 273mm and a wall thickness of 4mm, the inclined steel pipe pile support adopted by the present invention has greater rigidity and is not easily damaged during the excavation process.

[0046] Before excavation of the foundation pit, a support structure is usually required around the foundation pit, including Larsen steel sheet piles, steel cement soil mixing walls, cast-in-place piles, etc. A cap beam 7 is usually set on the top of the support structure to connect the support piles to form an integral force system to increase the stability of the entire support structure.

[0047] In the oblique steel pipe pile support provided by the present invention, the top end of the top conventional section 1 is connected to the crown beam 7 at the top of the foundation pit peripheral support structure through the reinforcement pier 8.

[0048] like Figure 2 , Figure 3 and Figure 4As shown, the top conventional section 1, the middle grouting section 2 and the bottom decompression section 3 provided by the present invention are hollow structures, and a plurality of grouting pipes are evenly fixed in the circumferential direction inside. In the present invention, the grouting pipes are divided into lateral grouting pipes 101 for lateral soil reinforcement in the phreatic layer 12 and end grouting pipes 302 for end soil reinforcement in the confined water layer 13. Both the lateral grouting pipes 101 and the end grouting pipes 302 can be made of φ48×3 steel pipes.

[0049] In the oblique steel pipe pile support provided by the present invention, on the side wall of the middle grouting section 2, a plurality of lateral grouting holes 201 for lateral soil reinforcement are provided at intervals along the axial direction of the lateral grouting pipe 101. It should be noted that in the present invention, the diameter of the lateral grouting hole 201 can be selected to be 15-20 mm. The center distance of the coaxial lateral grouting holes 201 provided on the lateral grouting pipe 101 is 150-250 mm. Those skilled in the art can select the appropriate diameter and spacing of the lateral grouting holes 201 according to the actual working conditions.

[0050] In the oblique steel pipe pile support provided by the present invention, a plurality of filter holes 301 for releasing the pressure of the pressurized water are provided on the side wall of the bottom pressure relief section 3. The filter holes 301 are evenly distributed in the axial and circumferential directions of the side wall of the bottom pressure relief section 3, and the positions of the filter holes 301 are away from the end grouting pipe 302 to avoid grout leakage.

[0051] In order to avoid that soil particles in the confined water layer 13 also enter through the filter hole 301 and cause blockage during the release of the confined water pressure. In this embodiment, three layers of nylon mesh are arranged on the periphery of the bottom pressure reducing section 3, and the aperture of the nylon mesh is 60 mesh. A layer of wire mesh is also arranged outside the nylon mesh for reinforcement, and the aperture of the wire mesh is 7 mesh. Those skilled in the art can select the number of layers and aperture of the nylon mesh and the aperture of the wire mesh according to the specific working conditions. The aperture of the nylon mesh is 60-80 mesh, and the aperture of the wire mesh is 5-10 mesh.

[0052] like Figure 6 As shown, the end grouting head 4 provided by the present invention is a conical structure for reducing resistance. Specifically, a conical cross pile tip can be used, and a 14mm thick steel plate is welded into a conical whole. Figure 5 As shown, the end grouting head 4 is provided with an end grouting hole 401 connected with the end grouting pipe 302. Temporary sealing tapes are provided on the end grouting head 4 and the lateral grouting hole 201. During grouting, the grouting pressure is increased, and grouting is performed by relying on the slurry to break through the tape.

[0053] In order to improve the stability and safety of the entire support structure, it is necessary to set up a reinforcement pier 8 to connect the oblique steel pipe pile support and the crown beam 7. Figure 7 As shown, a force transfer plate 5 is fixed to the top outer wall of the top conventional section 1, and a reinforcement pier 8 is cast outside the force transfer plate 5. The load supported by the oblique steel pipe piles is transferred to the crown beam 7 through the force transfer plate 5 and the reinforcement pier 8.

[0054] Taking the foundation pit with an excavation depth of 6m as an example, the inclined steel pipe pile support with a total length of 20m is designed, and the various components and supporting construction methods are introduced. The inclined steel pipe pile support is divided into four parts from top to bottom: the top conventional section 1, the middle grouting section 2, the bottom decompression section 3 and the end grouting head 4. The inclination angle can be adjusted according to the design requirements.

[0055] In this embodiment, the oblique steel pipe pile support adopts φ630×14 steel pipe piles, that is, the outer diameter of the top conventional section 1, the middle grouting section 2 and the bottom pressure relief section 3 are all 630mm and the wall thickness is 14mm. Eight grouting pipes are evenly welded along the circumference on the inner side of the oblique steel pipe pile support, and the grouting pipes are all steel pipes with an outer diameter of 48mm and a wall thickness of 3mm. Among the 8 grouting pipes, 4 are lateral grouting pipes 101 for lateral soil reinforcement in the submerged layer 12, and the other 4 are end grouting pipes 302 for end soil reinforcement in the confined water layer 13. Among them, the 4 lateral grouting pipes 101 are welded with 3mm thick steel plates at the bottom of the middle grouting section to prevent slurry leakage.

[0056] On the side wall of the middle grouting section 2, a lateral grouting hole 201 with a diameter of 16 mm is opened axially at the position of the lateral grouting pipe 101, and the center distance between adjacent lateral grouting holes 201 is 200 mm.

[0057] A plurality of filter holes 301 for releasing the pressure of the pressurized water are axially provided on the outer side wall of the bottom pressure relief section 3. In the axial direction, the center distance between adjacent filter holes 301 is 100 mm. The filter holes 301 are also evenly distributed in the circumferential direction of the side wall of the bottom pressure relief section 3, with a total of 20 filter holes 301 in each section. The diameter of the filter holes 301 provided in this embodiment is 10 mm.

[0058] In order to prevent soil particles in the confined water layer 13 from entering through the filter holes 301 and causing blockage during the release of the confined water pressure, in this embodiment, three layers of 60-mesh nylon mesh are arranged around the bottom decompression section 3, and one layer of 7-mesh galvanized wire mesh is arranged to fix the nylon mesh.

[0059] In this embodiment, the top of the top conventional section 1 supported by the oblique steel pipe pile is connected to the crown beam 7 through the reinforcing pier 8. The reinforcing pier 8 is made of reinforced concrete and has a size of 1800mm×2000mm×700mm. At the height center of the reinforcing pier 8, a force transfer plate 5 is welded to the top periphery of the top conventional section 1. After the concrete 6 of the reinforcing pier 8 is poured, the force transfer plate 5 is fixed to form a force transmission system. The force transfer plate 5 used in this embodiment is a 14mm thick double-piece steel plate with an outer diameter of 1500mm. The center of the oblique steel pipe pile support remains hollow, and grouting can be performed at any time during use to strengthen the reinforcement body. When sealing, the position of the water pump in the pile can be adjusted to adjust the precipitation depth.

[0060] Using the above-mentioned inclined steel pipe pile support construction method, the construction diagram is as follows Fig. 9 The specific steps are as follows:

[0061] (1) According to the plane size of the foundation pit, the excavation depth and the hydrogeological conditions, the support design and in-depth design are carried out to determine the number and total length of the inclined steel pipe pile support and the length of the top conventional section 1, the middle grouting section 2 and the bottom pressure relief section 3, and then complete the production. In this embodiment, the support structure around the foundation pit also includes three-axis cement mixing piles 10 and bored cast-in-place piles 11.

[0062] It should be noted that the three-axis cement mixing pile 10 sprays cement into the soil through a mixing pile machine and fully mixes it, so that the cement and the soil undergo a physical and chemical reaction, thereby increasing the strength of the soil and reducing the permeability of the soil, and can be used as a water-stop curtain. The bored pile 11 forms a pile body with greater rigidity by drilling a hole, lowering a steel cage, and pouring concrete 6. It can more effectively control the lateral deformation of the foundation pit during the earth excavation process, and is a more reliable form of supporting piles. In this embodiment, the three-axis cement mixing pile 10 plays a water-stopping role, and the bored pile 11 plays a retaining role.

[0063] (2) If Fig. 9 As shown, according to the inclination angle determined by the design, a pile driver is used to press the inclined steel pipe pile support, so that the middle grouting section 2 is located in the submerged layer 12, and the bottom pressure relief section 3 is located in the confined water layer 13. At this time, the inclined steel pipe pile support realizes the pressure relief effect at the bottom of the pit. After reaching the design elevation, grouting is carried out from the grouting pipe 101, and the slurry passes through the lateral grouting pipe 101 and the lateral grouting hole 201 to form a lateral reinforcement body 14 in the submerged layer 12. The slurry passes through the end grouting pipe 302 and the end grouting hole 401 to form an end reinforcement body 15 in the confined water layer 13.

[0064] (3) If Fig.10 As shown, when the water level outside the foundation pit drops to the design elevation, the water level inside the foundation pit is lowered to below the elevation of the bottom surface of the reinforced pier 8 by using the dewatering well 9 inside the pit, and the foundation pit is excavated to the elevation of the bottom surface of the reinforced pier 8. The portion of the top conventional section 1 that is higher than the elevation of the top surface of the reinforced pier 8 is cut off, and a force transfer plate 5 is welded to the outer wall of the top of the top conventional section 1, and the excess concrete 6 on the top of the supporting structure around the foundation pit is chiseled off.

[0065] (4) If Fig.11 As shown, at the top of the foundation pit surrounding support structure, the crown beam 7 and the reinforcement pier 8 are simultaneously supported by formwork, reinforced with steel bars, and poured with concrete 6 to connect and form a whole.

[0066] (5) If Fig.12 As shown, when the water level in the foundation pit drops below the bottom surface of the foundation, excavate the earth to the bottom surface elevation of the foundation. According to the anti-floating design requirements of the building and the actual situation on site, determine whether the inclined steel pipe pile support needs to be retained.

[0067] If there is no need to retain the inclined steel pipe pile support, the details are as follows:

[0068] (1) If Figure 8 and Fig.13 As shown, a construction joint is left around the top conventional section 1 where the bottom surface of the foundation needs to be set, and the outer foundation is constructed first. When tying the steel bars, a water stop plate 16 is set at the construction joint position. At the same time, the strengthening pier 8 is chiseled out.

[0069] (2) If Fig.14 As shown, the inclined steel pipe piles are pulled up for support and recovered, and during the pulling process, grouting is performed synchronously through the end grouting pipe 302 to fill the underground holes caused by the pile pulling. After recovery, it can be used again in the foundation pit with a shallow excavation depth.

[0070] (3) If Fig.15 As shown, the remaining foundation construction, basement construction, fertilizer trough backfilling around the pit, and the drainage well 9 outside the pit have been closed.

[0071] If it is necessary to retain some inclined steel pipe pile supports, the details are as follows

[0072] (1) If Figure 8 and Fig.16 As shown, an annular water stop plate 16 is set by welding at the intersection of the top conventional section 1 and the foundation to construct the foundation.

[0073] (2) If Fig.17 As shown, the strengthening pier 8 is chiseled out, the top conventional section 1 above the pressure water head of 1 meter is cut off, and the decompression function of the inclined steel pipe pile support is retained. The underground structure and superstructure are continued to be constructed, the fertilizer trough around the pit is backfilled, and the dewatering well 9 outside the pit is closed.

[0074] (3) If Fig.18 As shown, after the anti-floating of the underground structure meets the design requirements, the water level in the inclined steel pipe support is lowered to below the bottom surface of the foundation and kept stable, the top conventional section 1 above the top surface of the foundation is cut off, and underwater concrete 6 is filled in the cut-off part, the closed steel plate is welded, and the micro-expansion concrete 6 is filled to complete the plugging.

[0075] In this embodiment, four lateral grouting pipes are responsible for lateral soil reinforcement, and four end grouting pipes are responsible for end soil reinforcement. Preferably, the number of lateral and end grouting pipes can be adjusted according to the hydrogeological conditions of the phreatic layer 12 and the confined water layer 13, with emphasis on strengthening the lateral or end soil strength, further improving the bearing capacity of the oblique steel pipe pile support, and ensuring the safety of the foundation pit project.

[0076] The above-described embodiment is only a preferred solution of the present invention, but it is not intended to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. An inclined steel pipe pile support with pit bottom pressure relief and bidirectional grouting functions, characterized in that: The oblique steel pipe pile support is arranged in the excavated foundation pit, and comprises, from top to bottom, a top conventional section (1), a middle grouting section (2), a bottom pressure relief section (3) and an end grouting head (4); the top end of the top conventional section (1) is connected to the crown beam at the top of the foundation pit peripheral support structure through a reinforcement pier; The top conventional section (1), the middle grouting section (2) and the bottom pressure relief section (3) are hollow structures that are interconnected, and a plurality of grouting pipes are evenly fixed on the inner side along the circumferential direction, and the grouting pipes are divided into lateral grouting pipes (101) for lateral soil reinforcement in the submerged layer and end grouting pipes (302) for end soil reinforcement in the confined water layer; a force transfer plate (5) is fixed to the top outer wall of the top conventional section (1), and a reinforcement pier is cast outside the force transfer plate (5); through the force transfer plate (5) and the reinforcement pier, the oblique steel pipe pile support is connected with the crown beam and the support pile to form an overall force-bearing system; A plurality of lateral grouting holes (201) for lateral soil reinforcement are provided at intervals along the axial direction of the lateral grouting pipe (101) on the side wall of the middle grouting section (2); a plurality of filter holes (301) for releasing the pressure of the pressurized water are provided on the side wall of the bottom pressure reducing section (3); the filter holes (301) are evenly distributed in the axial direction and the circumferential direction of the side wall of the bottom pressure reducing section (3), and the filter holes (301) are provided at positions away from the end grouting pipe (302) to avoid grout leakage; the end grouting head (4) is a conical structure for reducing resistance; and the end grouting head (4) is provided with an end grouting hole (401) which is connected to the end grouting pipe (302).

2. The oblique steel pipe pile support according to claim 1, characterized in that: The top conventional section (1), the middle grouting section (2) and the bottom pressure relief section (3) are φ630×14 steel pipe piles.

3. The oblique steel pipe pile support according to claim 1, characterized in that: The grouting pipes (101) are all made of φ48×3 steel pipes.

4. The oblique steel pipe pile support according to claim 1, characterized in that: The end grouting head (4) adopts a conical cross pile tip and is welded into a whole with a 14 mm thick steel plate.

5. The oblique steel pipe pile support according to claim 1, characterized in that: The diameter of the lateral grouting hole (201) is 15-20 mm; the center distance between the coaxial lateral grouting holes (201) opened on the lateral grouting pipe (101) is 150-250 mm; and the diameter of the filter hole (301) is 8-12 mm.

6. The oblique steel pipe pile support according to claim 1, characterized in that: Four grouting pipes (101) are uniformly welded along the circumferential direction on the inner sides of the top conventional section (1), the middle grouting section (2) and the bottom pressure relief section (3).

7. The oblique steel pipe pile support according to claim 1, characterized in that: A nylon net is arranged on the periphery of the bottom pressure relief section (3) to prevent soil particles in the pressure water layer from entering the interior of the oblique steel pipe pile support; a wire mesh is fixed outside the nylon net.

8. The oblique steel pipe pile support according to claim 7, characterized in that: The aperture of the nylon mesh is 60-80 meshes, and the aperture of the wire mesh is 5-10 meshes.

9. The oblique steel pipe pile support according to claim 1, characterized in that: The force transmission plate (5) is made of a double-jointed steel plate with a thickness of 14 mm, and the outer diameter of the force transmission plate (5) is 1500 mm.

10. The oblique steel pipe pile support according to claim 1, characterized in that: The force transmission plate (5) and the top outer wall of the top conventional section (1) are fixed by welding.

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