A combined pile structure for deep foundation pit steel pipe grouting

Abstract

The invention discloses a combined pile structure for deep foundation pit steel pipe grouting, comprising an outer pipe body and an inner pipe body, wherein the inner sides of the outer pipe body and the inner pipe body are both provided with transverse discharge ports, the inner side of the conical tube is provided with a vertical discharge port, and the left and right sides of the outer pipe body are both provided with secondary grouting channels, and cement slurry entering the inner pipe body can flow into and fill nearby soil pores through the transverse discharge ports, so that during grouting, the soil pores near the outer pipe body can be filled first, and then grouting can be performed through the soil pores directly below the conical tube, and then cement slurry can be directly injected into the conical tube through the secondary grouting channel, and grouting can be performed on the cracks directly below through the vertical discharge port, and the separate grouting can fully grout the cracks in the two transverse directions and the vertical direction, so as to ensure that the flow rate and pressure of the cement slurry are relatively stable, and solve the problem that part of the cement slurry has solidified into blocks and it is impossible to ensure that the subsequent cement slurry can completely fill the surrounding gaps.

Description

Technical Field

[0001] The invention relates to the technical field of deep foundation pit grouting, in particular to a combined pile structure for deep foundation pit steel pipe grouting. Background Art

[0002] Deep foundation pit steel pipe grouting is an effective foundation pit support method, which mainly enhances the strength and stability of the soil by injecting slurry into the steel pipe. The specific construction steps include preparing grouting materials, burying grouting steel pipes, and using grouting pumps to press slurry into the soil pores. Grouting materials are usually composed of cement, sand, water, additives, etc., and must have good fluidity, stability and curing properties. During the grouting process, the grouting pressure, speed and grouting volume must be controlled to ensure that the slurry fully fills the soil pores and forms a good combination with the original soil. The detection and evaluation of the grouting effect is also an important link, which is usually carried out by core sampling, acoustic wave testing and other methods. This method is often used to deal with areas with high groundwater levels, loose soil or cracks to solve problems such as foundation settlement, slippage and leakage.

[0003] In the prior art, the grouting method is to insert a steel pipe into a deep foundation pit, and then inject grout into the steel pipe. During the grouting process, the cement slurry will preferentially penetrate downward into the soil pores below the steel pipe until the soil pores directly below the steel pipe are filled with cement slurry. However, the cement slurry flowing downward will leak radially outward through the lateral slurry outlet on the inner side of the steel pipe with the steel pipe as the center, causing part of the cement slurry to enter the soil gaps around the steel pipe in advance, but most of the cement slurry will be preferentially injected directly below the steel pipe, causing a small amount of cement slurry around the steel pipe to contact with the soil. Accelerate the solidification rate. When the gap directly below the steel pipe is filled, the cement slurry will be pushed by pressure into the soil gaps around the steel pipe. However, since part of the cement slurry has solidified into blocks, it cannot be guaranteed that the subsequent cement slurry can completely fill the gaps around it. The flow rate of the cement slurry decreases, resulting in increased pressure. The increased pressure will give the grouting pump and construction workers on the ground the illusion that the bottom is already filled, thereby stopping the grouting without completely filling the gaps around it. Such operations will pose serious safety hazards to the entire building foundation. Summary of the invention

[0004] The object of the present invention is to provide a combined pile structure for deep foundation pit steel pipe grouting to solve the problems raised in the prior art.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a combined pile structure for deep foundation pit steel pipe grouting, comprising an outer pipe body and an inner pipe body, a conical cylinder is fixedly installed at the bottom end of the outer pipe body, a main sealing cover and a secondary sealing cover are arranged above the outer pipe body, a horizontal discharge port is opened on the inner side of the outer pipe body and the inner pipe body, a vertical discharge port is opened on the inner side of the conical cylinder, and secondary grouting channels are arranged on the left and right sides of the outer pipe body;

[0006] The inner side of the outer tube body is provided with a slide groove, the outer surface of the inner tube body is provided with a convex groove, and the outer surface of the convex groove is slidably connected with the outer surface of the slide groove;

[0007] A limiting ring is provided on the inner wall of the outer tube body, and the top end of the limiting ring is fixedly mounted on the bottom end of the inner tube body;

[0008] The outer surface of the conical cylinder is fixedly provided with a plurality of barbs, the outer surface of the barbs is provided with three relatively sharp blades, the outer surface of the conical cylinder located at the vertical discharge port is rotatably connected with a rubber sheet, and the bottom end of the conical cylinder located at the vertical discharge port is fixedly provided with a cone bottom protection sheet.

[0009] Preferably, a feed inlet is fixedly mounted on the top end of the outer tube body, an inner wall of the feed inlet is threadedly connected to an outer surface of the secondary sealing cover, and a handle is fixedly mounted on the outer surface of the secondary sealing cover.

[0010] Preferably, a secondary grille is fixedly mounted on the inner surface of the secondary sealing cover, and the outer surface of the secondary sealing cover is in close contact with the top end and the outer surface of the inner tube body.

[0011] Preferably, the inner surface of the secondary sealing cover is threadedly connected to the outer surface of the main sealing cover, a primary grouting port is provided on the inner side of the main sealing cover, and a main grid is fixedly mounted on the inner wall of the main sealing cover.

[0012] Preferably, a fixing frame is fixedly mounted on the inner wall of the inner tube body, and a pull ring is fixedly mounted on the outer surface of the fixing frame.

[0013] Preferably, the outer surface of the outer tube body and the outer surface of the secondary grouting channel are fixedly mounted, and the interior of the secondary grouting channel and the inner side of the feed inlet are communicated with each other.

[0014] Preferably, a mixing plate is fixedly installed on the outer surface of the outer tube body close to the conical tube, the outer surface inclination angle of the mixing plate is the same as the inclination angle of the conical tube surface, and the interior of the secondary grouting channel is connected to the inner side of the mixing plate.

[0015] Preferably, the outer tube body is provided with a plurality of through grooves on the inner side of the mixing plate, the inner side wall of the through groove is rotatably connected with a one-way baffle, the inner surface of the through groove is provided with a baffle, and the outer surface of the baffle is in close contact with the outer surface of the one-way baffle.

[0016] Preferably, a secondary grouting port is opened on the inner side of the secondary sealing cover, and a sealing plug is threadedly connected to the inner wall of the secondary grouting port.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] 1. The present invention can vertically insert the outer tube into the deep foundation pit through the cooperation among the outer tube body, the inner tube body, the conical tube, the horizontal discharge port, the vertical discharge port and the secondary grouting channel, and then insert the inner tube body into the outer tube body, and inject cement slurry into the inner tube body. The cement slurry entering the inner tube body can flow into and fill the nearby soil pores through the horizontal discharge port, so that the soil pores near the outer tube body can be filled first during grouting, and then grouting can be performed through the soil pores directly below the conical tube, and then the cement slurry can be directly injected into the conical tube through the secondary grouting channel, and grouting can be performed for the cracks directly below it through the vertical discharge port, so that the soil cracks directly below and the horizontal soil cracks are grouted separately, and the separate grouting can fully grout the cracks in the two horizontal and vertical directions. Since there is no pre-solidified cement in the gaps flowing into during grouting, the flow rate and pressure of the cement slurry are ensured to be relatively stable, which solves the problem that part of the cement slurry has solidified into blocks and cannot ensure that the subsequent cement slurry can completely fill the gaps around.

[0019] 2. In the present application, the barbs on the surface of the conical tube can be inserted into the soil and not easily pulled out, so as to reduce the pressure increase below the outer tube during grouting and push the outer tube upward as a whole. When the grouting process is completed, the rubber sheet will reduce the speed of the cement slurry backfilling into the outer tube below. The cone bottom protection sheet can reduce the probability of deformation of the conical tube due to hard soil during the downward insertion of the outer tube.

[0020] 3. In the present application, through the cooperation among the through groove, the baffle, the one-way baffle, the mixing plate and the outer tube body, after the cement slurry enters the space formed between the mixing plate and the outer tube body, it can directly enter the through groove inside the outer tube body, and directly enter the inside of the outer tube body and the bottom of the inner tube body. During this period, the cement slurry can push the one-way baffle. When the pressure directly below the outer tube body increases or the grouting stops, the cement slurry directly below will surge back due to the pressure, but the surged cement slurry will push the one-way baffle, so that the one-way baffle will resist the baffle, forcing the surged cement slurry to be unable to enter the space formed between the outer tube body and the mixing plate, thereby preventing the secondary grouting channel from flowing back. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the overall structure of a combined pile structure for deep foundation pit steel pipe grouting according to the present invention;

[0022] Figure 2 It is a schematic diagram of the main explosion structure of a combined pile structure for deep foundation pit steel pipe grouting according to the present invention;

[0023] Figure 3 It is a schematic diagram of the explosion structure above the outer tube body and the inner tube body of a combined pile structure of deep foundation pit steel tube grouting of the present invention;

[0024] Figure 4 It is a schematic diagram of the overall disassembly structure of the outer tube body of a combined pile-type structure for deep foundation pit steel pipe grouting according to the present invention;

[0025] Figure 5 It is a schematic diagram of the overall bottom structure of a combined pile structure for deep foundation pit steel pipe grouting according to the present invention;

[0026] Figure 6 It is a schematic diagram of the overall bottom internal structure of a combined pile structure for deep foundation pit steel pipe grouting according to the present invention;

[0027] Figure 7 It is a schematic diagram of the overall top cross-sectional plane structure of a combined pile structure for deep foundation pit steel pipe grouting according to the present invention;

[0028] Figure 8 It is a schematic diagram of the overall bottom cross-sectional plane structure of a combined pile structure for deep foundation pit steel pipe grouting according to the present invention;

[0029] Fig. 9 The present invention is a schematic diagram of the internal planar structure of a through-channel of a combined pile-type structure for steel pipe grouting in a deep foundation pit.

[0030] Numbers in the figure: 1. Outer tube body; 2. Inner tube body; 3. Main sealing cover; 4. Secondary sealing cover; 5. Horizontal discharge port; 6. Vertical discharge port; 7. Secondary grouting channel; 8. Slide groove; 9. Convex groove; 10. Limiting ring; 11. Barb; 12. Conical cylinder; 13. Rubber sheet; 14. Cone bottom protection sheet; 15. Feed inlet; 16. Handle; 17. Secondary grille; 18. Primary grouting port; 19. Main grille; 20. Fixed frame; 21. Pull ring; 22. Mixing plate; 23. Through groove; 24. One-way baffle; 25. Block; 26. Secondary grouting port; 27. Sealing plug. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] Example: Figure 1-Figure 9 As shown, the present invention provides a technical solution of a combined pile structure for deep foundation pit steel pipe grouting, comprising an outer tube body 1 and an inner tube body 2, a conical cylinder 12 is fixedly installed at the bottom end of the outer tube body 1, a main sealing cover 3 and a secondary sealing cover 4 are arranged above the outer tube body 1, a horizontal discharge port 5 is opened on the inner side of the outer tube body 1 and the inner tube body 2, a vertical discharge port 6 is opened on the inner side of the conical cylinder 12, and secondary grouting channels 7 are arranged on the left and right sides of the outer tube body 1. The outer tube body 1 can be vertically inserted into the deep foundation pit, and then the inner tube body 2 is inserted into the outer tube body 1, and cement slurry is injected into the inner tube body 2. The cement slurry entering the inner tube body 2 can flow into and fill the nearby soil pores through the horizontal discharge port 5, so that it can be injected. During the grouting process, the soil pores near the outer tube body 1 are first filled, and then grouting is carried out through the soil pores directly below the conical tube 12. Subsequently, cement slurry can be directly injected into the conical tube 12 through the secondary grouting channel 7, and the cracks directly below it are grouted through the vertical discharge port 6, so that the soil cracks directly below and the horizontal soil cracks are grouted separately. The separate grouting can fully grout the cracks in both the horizontal and vertical directions. Since there is no pre-solidified cement flowing into the gaps during the grouting period, the flow rate and pressure of the cement slurry are relatively stable, thereby solving the problem that part of the cement slurry has solidified into blocks and the subsequent cement slurry cannot be guaranteed to completely fill the surrounding gaps.

[0033] A slide groove 8 is provided on the inner side of the outer tube body 1, and a convex groove 9 is provided on the outer surface of the inner tube body 2. The outer surface of the convex groove 9 is slidably connected to the outer surface of the slide groove 8. The inner tube body 2 can slide up and down on the inner wall of the outer tube body 1 and the surface of the slide groove 8 through the convex groove 9, thereby preventing the inner tube body 2 and the transverse discharge port 5 of the outer tube body 1 from being misaligned.

[0034] A limiting ring 10 is provided on the inner wall of the outer tube body 1, and the top end of the limiting ring 10 is fixedly installed with the bottom end of the inner tube body 2. The limiting ring 10 can play a minimum limiting role for the inner tube body 2, forcing the lateral discharge port 5 of the inner tube body 2 to be aligned with the lateral discharge port 5 of the outer tube body 1.

[0035] A number of barbs 11 are fixedly installed on the outer surface of the conical tube 12, and three relatively sharp blades are arranged on the outer surface of the barbs 11. A rubber sheet 13 is rotatably connected to the outer surface of the conical tube 12 located at the vertical discharge port 6. A cone bottom protection sheet 14 is fixedly installed on the bottom end of the conical tube 12 located at the vertical discharge port 6. The barbs 11 on the surface of the conical tube 12 can be difficult to be pulled out after being inserted into the soil, so as to reduce the pressure increase directly below the outer tube body 1 during grouting and push the outer tube body 1 upward as a whole. When the grouting step is completed, the rubber sheet 13 will reduce the speed at which the cement slurry directly below is backfilled into the outer tube body 1. The cone bottom protection sheet 14 can reduce the probability of deformation of the conical tube 12 due to hard soil during the downward insertion of the outer tube body 1.

[0036] A feed port 15 is fixedly installed at the top of the outer tube body 1, and the inner wall of the feed port 15 is threadedly connected to the outer surface of the secondary sealing cover 4. A handle 16 is fixedly installed on the outer surface of the secondary sealing cover 4, and secondary grouting can be performed on the feed port 15 to fill the soil gap directly below the outer tube body 1. The secondary sealing cover 4 can be easily rotated and screwed out through the handle 16. When the secondary sealing cover 4 is not screwed out, it can resist the inner tube body 2, so that the inner tube body 2 cannot move upward.

[0037] A secondary grille 17 is fixedly installed on the inner surface of the secondary sealing cover 4, and the outer surface of the secondary sealing cover 4 is in close contact with the top and outer surface of the inner tube body 2. The secondary grille 17 can intercept the lumps of yellow sand that appear in the cement slurry, and break these lumps with the impact of subsequent cement slurry.

[0038] The inner surface of the secondary sealing cover 4 is threadedly connected to the outer surface of the main sealing cover 3. A primary grouting port 18 is provided on the inner side of the main sealing cover 3. A main grid 19 is fixedly installed on the inner wall of the main sealing cover 3. The function of the main grid 19 is the same as that of the above-mentioned secondary grid 17, so no further description is given. The primary grouting port 18 is the entrance for the first grouting. During the first grouting, cement slurry can enter the interior of the inner tube body 2 through the primary grouting port 18.

[0039] A fixing frame 20 is fixedly mounted on the inner wall of the inner tube body 2, and a pull ring 21 is fixedly mounted on the outer surface of the fixing frame 20. The fixing frame 20 can provide support for the pull ring 21. During the secondary grouting, the pull ring 21 can assist the inner tube body 2 to slide upward.

[0040] The outer surface of the outer tube body 1 is fixedly installed with the outer surface of the secondary grouting channel 7, and the interior of the secondary grouting channel 7 is interconnected with the inner side of the feed port 15. A mixing plate 22 is fixedly installed on the outer surface of the outer tube body 1 located near the conical cylinder 12. The inclination angle of the outer surface of the mixing plate 22 is the same as the inclination angle of the surface of the conical cylinder 12. The interior of the secondary grouting channel 7 is interconnected with the inner side of the mixing plate 22. When the second grouting is performed, after the cement slurry enters the feed port 15, the cement slurry can enter the secondary grouting channel 7, so that the cement slurry can directly bypass the inner tube body 2 and directly enter the annular space formed between the mixing plate 22 and the outer tube body 1.

[0041] The outer tube body 1 is provided with a plurality of through grooves 23 on the inner side of the mixing plate 22. The inner side wall of the through groove 23 is rotatably connected with a one-way baffle 24. A stopper 25 is provided on the inner surface of the through groove 23. The outer surface of the stopper 25 is in close contact with the outer surface of the one-way baffle 24. After the cement slurry enters the space formed between the mixing plate 22 and the outer tube body 1, it can directly enter the through groove 23 on the inner side of the outer tube body 1 and directly enter the inside of the outer tube body 1 and the bottom of the inner tube body 2. During this period, the cement slurry can push the one-way baffle 24. When the pressure directly below the outer tube body 1 increases or the grouting stops, the cement slurry directly below will surge due to the pressure, but the surging cement slurry will push the one-way baffle 24, so that the one-way baffle 24 resists the stopper 25, forcing the surging cement slurry to be unable to enter the space formed between the outer tube body 1 and the mixing plate 22, thereby preventing the secondary grouting channel 7 from flowing back.

[0042] A secondary grouting port 26 is provided on the inner side of the secondary sealing cover 4, and a sealing plug 27 is threadedly connected to the inner wall of the secondary grouting port 26. Grouting can be directly injected into the feed inlet 15 through the secondary grouting port 26. After the grouting is completed, the sealing plug 27 can be rotated and inserted into the secondary grouting, and after the cement slurry solidifies, it will be connected to the sealing plug 27 as a whole.

[0043] In actual use, the inner tube body 2 is inserted into the outer tube body 1, and then the secondary sealing cover 4 is rotated and screwed into the feed port 15 to ensure that the inner tube body 2 does not slip out of the outer tube body 1. Then the outer tube body 1 is vertically inserted into the foundation pit soil, and the output end of the grouting pump is connected to the primary grouting port 18 through the output pipe, and then the first grouting is started. During the first grouting, the cement slurry can enter the main sealing cover 3 through the primary grouting port 18, and then enter the interior of the inner tube body 2 through the main grid 19. It can first enter the horizontal soil cracks around the outer tube body 1 through the horizontal discharge port 5 on the inner side of the inner tube body 2 and the outer tube body 1. When the pressure reaches a certain threshold, the grouting is stopped and the primary grouting port 18 is blocked, and the second grouting is prepared;

[0044] During the second grouting, the output end of the grouting pump needs to be connected to the secondary grouting port 26 through the output pipe, and then the secondary grouting begins. During the second grouting, the cement slurry can pass through the secondary grouting port 26 and the auxiliary grid 17 to enter the feed port 15, and the pressure of the grouting pump allows the cement slurry to enter the secondary grouting channel 7. The cement slurry can enter the annular space composed of the mixing plate 22 and the outer tube body 1 through the secondary grouting channel 7, and enter the conical tube 12 through the through groove 23 on the inner side of the outer tube body 1. And enter the soil cracks directly below the outer tube body 1 through the vertical discharge port 6 on the inner side of the conical cylinder 12, and stop grouting after the pressure reaches a certain threshold, and block the secondary grouting port 26 with the sealing plug 27. At this point, the grouting is completed. Within six hours after the grouting is completed, the cement slurry is in a semi-solidified state, and the secondary sealing cover 4 can be screwed out, and the inner tube body 2 can be quickly pulled out through the pull ring 21, and the inside of the outer tube body 1 can be re-grouted, so that the cement slurry fills the inside of the outer tube body 1, and the secondary sealing cover 4 can be screwed back into place.

[0045] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A combined pile structure for deep foundation pit steel pipe grouting, characterized in that: The invention comprises an outer tube body (1) and an inner tube body (2), wherein a conical cylinder (12) is fixedly mounted on the bottom end of the outer tube body (1), a main sealing cover (3) and a secondary sealing cover (4) are arranged above the outer tube body (1), a horizontal discharge port (5) is provided on the inner side of the outer tube body (1) and the inner tube body (2), a vertical discharge port (6) is provided on the inner side of the conical cylinder (12), and secondary grouting channels (7) are provided on the left and right sides of the outer tube body (1); The inner side of the outer tube body (1) is provided with a slide groove (8), the outer surface of the inner tube body (2) is provided with a convex groove (9), and the outer surface of the convex groove (9) is slidably connected to the outer surface of the slide groove (8); A limiting ring (10) is provided on the inner wall of the outer tube body (1), and the top end of the limiting ring (10) is fixedly mounted on the bottom end of the inner tube body (2); A plurality of barbs (11) are fixedly mounted on the outer surface of the conical cylinder (12), and three relatively sharp blades are arranged on the outer surface of the barbs (11). A rubber sheet (13) is rotatably connected to the outer surface of the conical cylinder (12) located at the vertical discharge port (6), and a cone bottom protection sheet (14) is fixedly mounted on the bottom end of the conical cylinder (12) located at the vertical discharge port (6); A material inlet (15) is fixedly mounted on the top of the outer tube body (1), the inner wall of the material inlet (15) is threadedly connected to the outer surface of the secondary sealing cover (4), and a handle (16) is fixedly mounted on the outer surface of the secondary sealing cover (4); The outer surface of the outer tube body (1) and the outer surface of the secondary grouting channel (7) are fixedly mounted, and the interior of the secondary grouting channel (7) and the inner side of the feed inlet (15) are connected to each other; A mixing plate (22) is fixedly mounted on the outer surface of the outer tube body (1) located near the conical cylinder (12); the outer surface of the mixing plate (22) has an inclination angle that is the same as the inclination angle of the surface of the conical cylinder (12); and the interior of the secondary grouting channel (7) is connected to the inner side of the mixing plate (22); The outer tube body (1) is provided with a plurality of through grooves (23) on the inner side of the mixing plate (22); the inner side walls of the through grooves (23) are rotatably connected to a one-way baffle (24); the inner surface of the through grooves (23) is provided with a baffle (25); the outer surface of the baffle (25) is in close contact with the outer surface of the one-way baffle (24).

2. A combined pile structure for deep foundation pit steel pipe grouting according to claim 1, characterized in that: A secondary grille (17) is fixedly mounted on the inner surface of the secondary sealing cover (4), and the outer surface of the secondary sealing cover (4) is in close contact with the top end and outer surface of the inner tube body (2).

3. The combined pile structure for deep foundation pit steel pipe grouting according to claim 1 is characterized in that: The inner surface of the secondary sealing cover (4) is threadedly connected to the outer surface of the main sealing cover (3); a primary grouting port (18) is provided on the inner side of the main sealing cover (3); and a main grille (19) is fixedly mounted on the inner wall of the main sealing cover (3).

4. The combined pile structure for deep foundation pit steel pipe grouting according to claim 1 is characterized in that: A fixing frame (20) is fixedly mounted on the inner wall of the inner tube body (2), and a pull ring (21) is fixedly mounted on the outer surface of the fixing frame (20).

5. The combined pile structure for deep foundation pit steel pipe grouting according to claim 1 is characterized in that: A secondary grouting port (26) is provided on the inner side of the secondary sealing cover (4), and a sealing plug (27) is threadedly connected to the inner wall of the secondary grouting port (26).

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