Oblique steel pipe pile support with dewatering and end grouting functions
By adopting the oblique steel pipe pile support with drying precipitation and end grouting functions in the oblique composite pile support, the problems of large material consumption, long construction period and high cost in the prior art are solved, and the construction period is shortened, cost reduction and reuse of steel pipe piles are achieved.
Patent Information
- Application Number
- CN202421093367.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-20
- Publication Date
- 2025-03-11
- Estimated Expiration
- 2034-05-20
AI Technical Summary
In the foundation pit project, the existing oblique composite pile support has problems such as large material consumption, long construction period, high cost, difficult to adjust the reinforcement strength in real time, difficult to reuse steel lattice piles, and large number of precipitation wells in the pit and easy to damage.
The oblique steel pipe pile support is adopted with dry precipitation and end grouting functions. The soil reinforcement and precipitation functions are realized through the standard section of the pile body of the hollow structure and the pile end grouting head of the conical structure, and the load is transferred to the crown beam through the force transmission plate and reinforcement pier.
The construction period is shortened, construction costs are reduced, the number of precipitation wells in the pit is reduced, the flexibility of soil reinforcement and the bearing capacity of steel pipe piles are improved, and steel pipe piles can be reused.
Smart Images
Figure CN222594878U_ABST
Abstract
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 drainage and precipitation and end grouting functions. Background Art
[0002] In the southeast coastal areas, "cast-in-place piles + water-stop curtains + dewatering inside and outside the pit + horizontal internal supports" is the most commonly used and reliable foundation pit support solution. However, for foundation pit projects with large plane areas, a large number of horizontal internal supports not only consume a lot of materials, but also hinder the excavation and transportation of earthwork in the pit, thus seriously affecting the progress of the project. In recent years, oblique composite pile support has gradually been adopted by more units due to its advantages such as low material consumption, flexible plane layout, and convenient earthwork excavation.
[0003] 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 pre-reinforce the soil and drill holes, and then insert the prefabricated steel lattice pile obliquely into the holes. After the cementitious materials such as cement solidify, they will form lateral and end reinforcement bodies around and below the steel lattice piles, thereby improving the bearing capacity of the steel lattice piles. However, the above conventional practices have the following shortcomings: (1) Mixing reinforcement takes a long time, which affects the construction period, and the cementitious materials used are more, which increases the cost; (2) Mixing reinforcement is usually carried out in advance. If there is a risk in the foundation pit during the earthwork excavation process, the strength of the reinforcement 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 dewatering wells in the pit need to be set up separately. For foundation pits with larger plane areas, the number of dewatering wells in the pit is large, and the cost is high; (5) The dewatering wells in the pit are usually made of PVC corrugated pipes, which are difficult to protect during the earthwork excavation process and are easily damaged once they are hit by mechanical equipment. If the number of precipitation wells is insufficient, additional wells need to be added, which further increases the cost. Therefore, it is urgent to improve the existing oblique composite pile support manufacturing method and construction process. Utility Model Content
[0004] The utility model aims to solve the deficiencies in the prior art and provide an inclined steel pipe pile support with drainage and precipitation and end grouting functions.
[0005] The specific technical solutions adopted by this utility model are as follows:
[0006] The utility model provides an inclined steel pipe pile support with drainage and dewatering and end grouting functions, wherein the inclined steel pipe pile support is arranged in a foundation pit to be excavated, and comprises a pile body standard section and a pile end grouting head; the pile end grouting head is arranged at the bottom end of the pile body standard section, and the top end of the pile body standard section is connected to the crown beam at the top of the foundation pit peripheral support structure through a reinforcement pier;
[0007] The standard section of the pile body is a hollow structure, and a number of grouting pipes are evenly fixed along the circumferential direction on the inner side of the standard section of the pile body; a number of filter holes for drainage and precipitation are opened on the side wall of the standard section of the pile body; the filter holes are evenly distributed in the axial direction and circumferential direction of the side wall of the standard section of the pile body, and the positions where the filter holes are opened avoid the grouting pipes to avoid leakage;
[0008] The pile end grouting head is a conical structure for reducing resistance; a pile end grouting hole is opened on the pile end grouting head, and the outlet of the grouting pipe inside the standard section of the pile body corresponds to the pile end grouting hole; a force transfer plate is fixed to the top outer wall of the standard section of the pile body, and a reinforcement pier is cast outside the force transfer plate; the load supported by the oblique steel pipe pile is transferred to the crown beam through the force transfer plate and the reinforcement pier.
[0009] Preferably, the standard section of the pile body adopts φ630×14 steel pipe piles.
[0010] Preferably, the grouting pipes are all made of φ48×3 steel pipes.
[0011] Preferably, the pile end grouting head adopts a conical cross pile tip, which is welded into a whole with a 14 mm thick steel plate.
[0012] Preferably, four grouting pipes are uniformly welded along the circumferential direction on the inner side of the standard section of the pile body.
[0013] Preferably, a nylon net is arranged outside the standard section of the pile body to prevent stratum soil from entering the interior; and a wire mesh is fixed outside the nylon net.
[0014] Preferably, the aperture of the nylon mesh is 60-80 meshes, and the aperture of the wire mesh is 5-10 meshes.
[0015] Preferably, the diameter of the filter hole is 8 to 12 mm.
[0016] 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.
[0017] Preferably, the force transfer plate and the top outer wall of the standard section of the pile body are fixed by welding.
[0018] Compared with the prior art, the utility model has the following beneficial effects:
[0019] (1) The inclined steel pipe pile support provided by the utility model does not require the soil to be reinforced in advance, and the pile end grouting can be carried out at a later stage, which is conducive to shortening the construction period and effectively reducing the construction cost. After the bottom soil of the pit is dewatered, the side resistance of the pile is improved; after the pile end is grouting, the resistance at the bottom of the pile is significantly enhanced. The combined effect of these two ensures that the bearing capacity of the steel pipe pile can meet the design requirements.
[0020] (2) The inclined steel pipe pile support provided by the utility model has the function of draining and dewatering, so the number of dewatering wells in the pit can be significantly reduced. In particular, for foundation pits with smaller areas, there is no need to set up additional dewatering wells, which further reduces costs. Compared with traditional PVC corrugated pipe dewatering wells, the inclined steel pipe pile support is not easily damaged during the excavation process, which helps to ensure the continuity of the dewatering operation.
[0021] (3) During the earth excavation process, if a dangerous situation occurs in the foundation pit, the strength of the reinforcement body can be increased by re-grouting the inclined steel pipe pile support to enhance the emergency response capability.
[0022] (4) For inclined steel pipe pile supports that do not need to be permanently 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. BRIEF DESCRIPTION OF THE DRAWINGS
[0023] Figure 1 A schematic diagram of the installation of the oblique steel pipe pile support provided in this embodiment;
[0024] Figure 2 for Figure 1 Sectional view at AA;
[0025] Figure 3 for Figure 1 Cross-section at the middle BB;
[0026] Figure 4 A schematic diagram of a pile end grouting head provided in this embodiment;
[0027] Figure 5 for Figure 1 Cross-section at CC;
[0028] Figure 6 for Figure 1 Sectional view at DD;
[0029] Figure 7 This is a schematic diagram of the pressed-in oblique steel pipe pile support and grouting in the embodiment;
[0030] Figure 8 It is a schematic diagram of the elevation of the earth excavation to the bottom surface of the reinforcement pier in the embodiment;
[0031] Fig. 9 It is a schematic diagram of strengthening pier construction in the embodiment;
[0032] Fig.10 This is a schematic diagram of the elevation of the earth excavation to the bottom surface of the foundation in the embodiment;
[0033] Fig.11 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;
[0034] Fig.12 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;
[0035] Fig.13 In order to avoid retaining the oblique steel pipe pile support construction, the remaining foundation construction diagram is shown;
[0036] Fig.14 In order to retain some inclined steel pipe piles to support the construction, the foundation construction diagram is shown;
[0037] Fig.15 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;
[0038] Fig.16 In order to retain some inclined steel pipe piles to support the construction, the schematic diagram of the blocking construction is shown;
[0039] In the figure: standard section of pile body 1, pile end grouting head 2, grouting pipe 101, filter hole 102, pile end grouting hole 201, force transfer plate 3, concrete 4, cap beam 5, reinforcement pier 6, dewatering well 7, three-axis cement mixing pile 8, bored pile 9, water stop plate 10, end reinforcement body 11. DETAILED DESCRIPTION
[0040] 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.
[0041] like Figure 1 As shown, in a preferred embodiment of the utility model, an inclined steel pipe pile support with drainage and end grouting functions is provided. The inclined steel pipe pile support is arranged in a foundation pit to be excavated, and comprises a pile body standard section 1 and a pile end grouting head 2, and the pile end grouting head 2 is arranged at the bottom end of the pile body standard section 1.
[0042] 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 5 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.
[0043] The top end of the standard section 1 of the pile body in the oblique steel pipe pile support provided by the utility model is connected to the crown beam 5 at the top of the supporting structure around the foundation pit through the reinforcing pier 6.
[0044] like Figure 2 As shown, the pile body standard section 1 provided by the utility model is a hollow structure, and a plurality of grouting pipes 101 are evenly fixed along the circumferential direction on the inner side of the pile body standard section 1. A plurality of filter holes 102 for drainage and precipitation are also provided on the side wall of the pile body standard section 1, and the diameter of the filter hole 102 is 8 to 12 mm. The filter holes 102 are evenly distributed in the axial and circumferential directions of the side wall of the pile body standard section 1. Since the pile body standard section 1 is a hollow structure, during actual construction, a water pump can be placed inside the pile body standard section 1, and the submerged water in the soil layer in the foundation pit can enter the inner cavity of the pile body standard section 1 through the filter holes 102 and be discharged outside the pit, thereby achieving the effect of drainage and precipitation.
[0045] It should be noted that the position where the filter hole 102 is opened needs to avoid the grouting pipe 101 to avoid leakage. In order to avoid soil particles entering through the filter hole 102 during the drainage and precipitation process, causing blockage. In this embodiment, three layers of nylon mesh are arranged on the periphery of the standard section 1 of the pile body, 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, aperture of the nylon mesh and aperture of the wire mesh according to the specific working conditions. The aperture of the nylon mesh is 60 to 80 mesh, and the aperture of the wire mesh is 5 to 10 mesh.
[0046] like Figure 4 As shown, the pile end grouting head 2 provided by the utility model 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 3 As shown, a pile end grouting hole 201 is provided on the pile end grouting head 2, and the outlet of the grouting pipe 101 inside the pile body standard section 1 corresponds to the pile end grouting hole 201. A temporary sealing tape is provided on the pile end grouting hole 201. During grouting, the grouting pressure is increased, and grouting is performed by relying on the slurry to break through the tape.
[0047] In order to improve the stability and safety of the entire support structure, it is necessary to set up a reinforcement pier 6 to connect the oblique steel pipe pile support and the crown beam 5. Figure 5 As shown, a force transfer plate 3 is fixed to the top outer wall of the pile body standard section 1, and a reinforcement pier 6 is cast outside the force transfer plate 3. The load supported by the oblique steel pipe pile is transferred to the cap beam 5 through the force transfer plate 3 and the reinforcement pier 6.
[0048] Taking a foundation pit with an excavation depth of 6m as an example, the following describes the design of an inclined steel pipe pile support with a total length of 15m and introduces the various components and supporting construction methods.
[0049] In this embodiment, the pile body standard section 1 adopts a φ630×14 steel pipe pile, that is, the outer diameter of the pile body standard section 1 is 630mm and the wall thickness is 14mm. Four grouting pipes 101 are evenly welded along the circumferential direction on the inner side of the pile body standard section 1. The grouting pipes 101 are all steel pipes with an outer diameter of 48mm and a wall thickness of 3mm.
[0050] In this embodiment, a plurality of filter holes 102 for drainage and precipitation are provided along the axial direction of the side wall of the pile body standard section 1. In the axial direction of the pile body standard section 1, the center distance between adjacent filter holes 102 is 100 mm. The filter holes 102 are also evenly distributed in the circumferential direction of the side wall of the pile body standard section 1, with a total of 20 filter holes 102 in each section. The diameter of the filter holes 102 provided in this embodiment is 10 mm.
[0051] In order to prevent soil particles from entering through the filter holes 102 during drainage and precipitation, causing blockage, in this embodiment, three layers of 60-mesh nylon mesh are arranged around the pile body standard section 1, and one layer of 7-mesh galvanized wire mesh is arranged to fix the nylon mesh.
[0052] In this embodiment, the top of the standard section 1 of the pile body supported by the oblique steel pipe pile is connected to the crown beam 5 through the reinforcing pier 6. The reinforcing pier 6 is made of reinforced concrete and has a size of 1800mm×2000mm×700mm. At the height center of the reinforcing pier 6, a force transfer plate 3 is welded on the periphery of the top of the standard section 1 of the pile body. After the concrete 5 of the reinforcing pier 6 is poured, the force transfer plate 3 is fixed to form a force transmission system. The force transfer plate 3 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 the reinforcement body can be grouted at any time during use, and the position of the water pump in the pile can be adjusted at any time to adjust the precipitation depth.
[0053] The specific steps of the construction method using the above-mentioned oblique steel pipe pile support are as follows:
[0054] (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 length of the oblique steel pipe pile support and complete the production. In this embodiment, the support structure around the foundation pit also includes three-axis cement mixing piles 8 and bored cast-in-place piles 9. Among them, the three-axis cement mixing piles 8 play a water-stopping role, and the bored cast-in-place piles 9 play a soil retaining role.
[0055] (2) Figure 7 As shown, according to the tilt angle determined by the design, a pile driver is used to press in the oblique steel pipe pile support. After the pile end grouting head 2 reaches the designed elevation, grouting is performed from several grouting pipes 101 inside the pile body standard section 1, so that the slurry flows out from the pile end grouting head 2 to form the end reinforcement body 11.
[0056] (3) Figure 8As shown, when the water level outside the foundation pit drops to the design elevation and the water level inside the foundation pit drops below the elevation of the bottom surface of the reinforced pier 6, the foundation pit is excavated to the elevation of the bottom surface of the reinforced pier 6. The portion of the pile body standard section 1 that is higher than the elevation of the top surface of the reinforced pier 6 is cut off, and a force transfer plate 3 is welded to the outer wall at the top of the pile body standard section 1, and the excess concrete 4 on the top of the supporting structure around the foundation pit is chiseled off.
[0057] (4) Fig. 9 As shown, at the top of the foundation pit surrounding support structure, the crown beam 5 and the reinforcement pier 6 are simultaneously supported by formwork, steel bars are tied, and concrete 4 is poured to connect them to form a whole.
[0058] (5) Fig.10 As shown, when the water level in the foundation pit drops below the foundation bottom surface, the foundation pit is excavated to the foundation bottom surface elevation. According to the building anti-floating design requirements and the actual situation on site, it is determined whether the inclined steel pipe pile support needs to be retained.
[0059] If there is no need to retain the inclined steel pipe pile support, the details are as follows:
[0060] (1) Figure 6 and Fig.11 As shown, a construction joint is left around the pile body standard section 1 where the foundation bottom surface needs to be set, and the peripheral foundation is constructed first. When tying the steel bars, a water stop plate 10 is set at the construction joint position. At the same time, the strengthening pier 6 is chiseled out.
[0061] (2) Fig.12 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 grouting pipe 101 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.
[0062] (3) Fig.13 As shown, the remaining foundation construction, underground structure construction, fertilizer trough backfilling around the pit, and the drainage well 7 outside the pit are closed.
[0063] If it is necessary to retain some inclined steel pipe pile supports, the details are as follows:
[0064] (1) Figure 6 and Fig.14 As shown, an annular water stop plate 10 is set by welding at the intersection of the pile body standard section 1 and the foundation to construct the foundation.
[0065] (2) Fig.15 As shown, the strengthening pier 6 is chiseled out, the standard section 1 of the pile body above the top surface of the foundation is cut off, and the dewatering function supported by the oblique steel pipe pile is retained. The underground structure and the upper structure are constructed, the fertilizer trough around the pit is backfilled, and the dewatering well 7 outside the pit is closed.
[0066] (3) Fig.16As shown, after the anti-floating property of the underground structure meets the design requirements, the water level in the inclined steel pipe support is lowered and kept stable, underwater concrete 4 is filled in the cut-off part, the closed steel plate is welded, and micro-expansion concrete 4 is filled to complete the plugging.
[0067] 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 oblique steel pipe pile support with drainage and end grouting functions, characterized in that: The oblique steel pipe pile support is arranged in a foundation pit to be excavated, and comprises a pile body standard section (1) and a pile end grouting head (2); the pile end grouting head (2) is arranged at the bottom end of the pile body standard section (1), and the top end of the pile body standard section (1) is connected to the crown beam at the top of the foundation pit peripheral support structure through a reinforcement pier; The pile body standard section (1) is a hollow structure, and a plurality of grouting pipes (101) are evenly fixed along the circumferential direction on the inner side of the pile body standard section (1); a plurality of filter holes (102) for drainage and precipitation are provided on the side wall of the pile body standard section (1); the filter holes (102) are evenly distributed in the axial direction and circumferential direction of the side wall of the pile body standard section (1), and the filter holes (102) are provided at positions away from the grouting pipes (101) to avoid grout leakage; The pile end grouting head (2) is a conical structure for reducing resistance; a pile end grouting hole (201) is provided on the pile end grouting head (2); an outlet of a grouting pipe (101) inside the pile body standard section (1) corresponds to the pile end grouting hole (201); a force transmission plate (3) is fixed to the outer wall of the top end of the pile body standard section (1), and a reinforcement pier is cast outside the force transmission plate (3); the load supported by the oblique steel pipe pile is transmitted to the crown beam through the force transmission plate (3) and the reinforcement pier.
2. The oblique steel pipe pile support according to claim 1, characterized in that: The standard pile body section (1) adopts a φ630×14 steel pipe pile.
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 pile end grouting head (2) 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: Four grouting pipes (101) are uniformly welded in the circumferential direction on the inner side of the pile body standard section (1).
6. The oblique steel pipe pile support according to claim 1, characterized in that: A nylon net is arranged outside the standard section (1) of the pile body to prevent stratum soil from entering the interior; a wire mesh is fixed outside the nylon net.
7. The oblique steel pipe pile support according to claim 6, characterized in that: The aperture of the nylon mesh is 60-80 meshes, and the aperture of the wire mesh is 5-10 meshes.
8. The oblique steel pipe pile support according to claim 1, characterized in that: The diameter of the filter hole (102) is 8-12 mm.
9. The oblique steel pipe pile support according to claim 1, characterized in that: The force transmission plate (3) is made of a double-jointed steel plate with a thickness of 14 mm, and the outer diameter of the force transmission plate (3) is 1500 mm.
10. The oblique steel pipe pile support according to claim 1, characterized in that: The force transmission plate (3) and the top outer wall of the pile body standard section (1) are fixed by welding.