Soft rock pre-stressed anchor cable fixed-point pressure grouting structure

Abstract

The utility model relates to the technical field of foundation pit supporting construction, and particularly discloses a soft rock pre-stressed anchor cable fixed-point pressure grouting structure which comprises a steel strand, a primary grouting pipe, a secondary grouting pipe and a valve body, a grouting hole is formed in the primary grouting pipe, the valve body is arranged on the secondary grouting pipe, a grout outlet is formed in the valve body, and the grouting hole is communicated with the grouting hole. The valve body is provided with an adjusting assembly used for controlling the pulp outlet to be opened and closed. The anchor cable has the effect of improving the bearing capacity of the anchor cable.

Description

Technical Field

[0001] The present application relates to the technical field of foundation pit support construction, and in particular to a soft rock prestressed anchor fixed-point pressure grouting structure. Background Art

[0002] Chongqing is a region with many mountains and rivers. The surface morphology is mainly mountainous and hilly. The stratum conditions from top to bottom are mainly fill, silty clay, sandy mudstone and sandstone. The rapid development and construction of the city requires the protection of mountains and hills. The most commonly used and most space-saving method is the active protection measure of prestressed anchor frame beams, piles and prestressed anchor cables.

[0003] In order to ensure the safety of the overall protective structure, the anchoring section of the prestressed anchor cable must be set in stable sandstone or sandy mudstone. According to the provisions of the national standard "Technical Specifications for Building Slope Engineering" on rock categories, sandstone and sandy mudstone are judged to be soft rocks. Therefore, in the structural design of the anchoring section of the prestressed anchor cable, in order to meet the requirements of pull-out bearing capacity, the anchoring section design often exceeds the maximum length requirements specified in the specification. The specification also stipulates: When the calculated anchoring section length exceeds the required length of the structure, measures should be taken to improve the quality of the rock and soil mass of the anchoring section, expand the diameter of the anchoring section, and use load-distributing anchor cables to improve the bearing capacity of the anchor cable.

[0004] Since the first two measures are difficult to implement, and the material cost and processing cost of the load-distributing anchor cable are high, there is an urgent need for a technology that is simple to operate and easy to implement to solve this problem. Utility Model Content

[0005] In order to improve the bearing capacity of anchor cables, the present application provides a soft rock prestressed anchor cable fixed-point pressure grouting structure.

[0006] The present application provides a soft rock prestressed anchor fixed-point pressure grouting structure that adopts the following technical solution:

[0007] A soft rock prestressed anchor fixed-point pressure grouting structure comprises a steel strand, a primary grouting pipe, a secondary grouting pipe and a valve body, wherein the primary grouting pipe is provided with a grouting hole, the valve body is arranged on the secondary grouting pipe, the valve body is provided with a slurry outlet, and the valve body is provided with an adjusting component for controlling the opening and closing of the slurry outlet.

[0008] By adopting the above technical scheme, during construction, cement mortar is first injected into the anchor hole through the primary grouting pipe. After the cement mortar is initially set, cement mortar is injected into the anchor hole through the secondary grouting pipe. During the secondary pressure grouting, the slurry overflows from the valve body, which can effectively fill the interlayer cracks of the rock mass at specific locations and the gaps between the primary grouting body and the anchor hole wall, achieving the effect of filling and compacting, increasing the bonding friction between the rock and soil body and the anchor body, and thus improving the pull-out bearing capacity of the anchor structure.

[0009] Optionally, the length direction of the valve body is perpendicular to the axial direction of the anchor cable hole.

[0010] By adopting the above technical solution, the grout outlet can be located as close to the anchor hole wall as possible, providing the best working conditions for secondary pressure grouting, reducing the confining pressure of the primary grouting body, and thus improving the success rate of secondary pressure grouting.

[0011] Optionally, a plurality of slurry outlets are provided, and the slurry outlets are divided into two groups, and the two groups of slurry outlets are respectively located at two ends of the valve body.

[0012] By adopting the above technical solution, since the slurry outlets are located on both sides, the grouting effect and efficiency can be enhanced.

[0013] Optionally, the adjusting assembly includes a block and a spring, the number of the block is the same as the number of slurry outlets, and each of the block corresponds to a slurry outlet, the block is slidably penetrated through the corresponding slurry outlet, a limit block is provided on one side of the block outside the valve body, and the spring is connected between the block and the valve body.

[0014] By adopting the above technical solution, the setting of the limit block allows the block to slide only on the outside of the valve body. Under normal circumstances, the spring causes the block to be inserted at the slurry outlet to close the slurry outlet. Therefore, during the first grouting, it is not easy for the slurry to enter the secondary grouting pipe through the slurry outlet to cause blockage; after the slurry is introduced into the secondary grouting pipe, under the action of the slurry pressure, the slurry can push the block to slide outward, thereby opening the slurry outlet, allowing the slurry to flow out smoothly and carrying out the secondary grouting.

[0015] Optionally, a conical surface is provided at one end of the blocking block outside the valve body.

[0016] By adopting the above technical solution, the resistance encountered by the block during sliding can be reduced, making it easier to open the slurry outlet.

[0017] Optionally, a limiting assembly is provided between the block and the valve body, and the limiting assembly includes a ratchet, a torsion spring and a rack, the rack is provided on the block, the ratchet is rotatably provided on the valve body, the torsion spring is connected between the ratchet and the valve body, and the torsion spring causes one end of the ratchet to press against the rack.

[0018] By adopting the above technical solution, when the block slides outward, it can drive the rack to slide, and the pawl will rotate accordingly. When the block tends to slide inward, the pawl limits the sliding of the rack, so that the block can only slide to the outside of the valve body. When the block slides out, the slurry outlet can be kept in an open state, which helps the slurry in the secondary grouting pipe to flow out smoothly.

[0019] Optionally, a connecting pipe is provided on the valve body, the connecting pipe is communicated with the interior of the valve body, and the connecting pipe is threadedly connected to the secondary grouting pipe.

[0020] By adopting the above technical solution, it is convenient to connect the valve body and the secondary grouting pipe, so that the specific positions of the rock interlayers and cracks can be determined according to the geological conditions and drilling construction records, so that the valve body can be installed at the corresponding position to achieve the effect of fixed-point grouting and further improve the pull-out resistance.

[0021] Optionally, a sealant is provided between the connecting pipe and the secondary grouting pipe.

[0022] By adopting the above technical solution, the sealing between the connecting pipe and the secondary grouting pipe can be enhanced, so that during the secondary grouting, the slurry is not easy to flow out through the gap between the connecting pipe and the secondary grouting pipe, thereby ensuring the grouting effect.

[0023] In summary, the present application includes at least one of the following beneficial technical effects:

[0024] 1. After the primary grouting, the secondary grouting is carried out. During the secondary grouting, the slurry flows out from the valve body to fill the gaps in the rock formation and the gaps between the primary grouting body and the anchor hole, making the slurry filling more compact, thereby increasing the bonding friction between the rock and soil body and the anchor body, thereby improving the pull-out bearing capacity of the anchoring structure.

[0025] 2. Under normal circumstances, the block will close the slurry outlet, making the valve in a closed state. During the first grouting, it is difficult for the slurry to enter through the slurry outlet, causing blockage. During the second grouting, the slurry can push the block out, allowing the valve to open, so that the slurry can flow smoothly into the anchor hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a cross-sectional view of an embodiment of the present application for showing the installation position of the anchor cable;

[0027] Figure 2 It is a schematic diagram of the overall structure of an embodiment of the present application;

[0028] Figure 3 is a schematic diagram of the structure of the adjustment component in the embodiment of the present application;

[0029] Figure 4 It is a schematic diagram of the structure of the limiting component in the embodiment of the present application.

[0030] Figure numerals: 1. anchor hole; 2. steel strand; 3. anchoring section; 4. free section; 5. primary grouting pipe; 51. grouting hole; 6. secondary grouting pipe; 7. valve body; 71. slurry outlet; 72. connecting pipe; 8. adjusting assembly; 81. blocking block; 811. conical surface; 812. limit block; 82. spring; 9. limiting assembly; 91. ratchet; 92. torsion spring; 93. rack; 10. clamping ring; 11. wire ring; 12. anchor; 13. connecting plate; 14. protective shell; 141. avoidance groove. DETAILED DESCRIPTION

[0031] The present application is further described in detail below in conjunction with the accompanying drawings.

[0032] The present application discloses a soft rock prestressed anchor fixed-point pressure grouting structure, which is described by taking its application in an anchor hole as an example. Figure 1 and Figure 2 The fixed-point pressure grouting structure of the soft rock prestressed anchor cable includes an anchor cable body, a primary grouting pipe 5 and a secondary grouting pipe 6. The anchor cable body includes four steel strands 2, and the steel strands 2 are arranged along the length direction of the anchor cable hole 1. The primary grouting pipe 5 and the secondary grouting pipe 6 are both fixedly connected to the anchor cable body, and the primary grouting pipe 5 and the secondary grouting pipe 6 are both arranged along the length direction of the anchor cable body. The anchor cable body includes an anchoring section 3 and a free section 4 arranged at one end of the anchoring section 3, the anchoring section 3 is located at the bottom end of the anchor cable hole 1, and the free section 4 is located at the top end of the anchor cable hole 1. The anchor cable body is provided with a clamping ring 10 and a wire-hanging ring 11. There are multiple clamping rings 10, which are evenly spaced on the anchoring section 3 and the free section 4. The clamping ring 10 and the steel strand 2 are fixed by steel wire binding. There are multiple wire-hanging rings 11, which are evenly spaced on the anchoring section 3. The wire-hanging ring 11 and the steel strand 2 are fixed by steel wire binding, and the wire-hanging rings 11 and the clamping ring 10 on the anchoring section 3 are staggered. Therefore, multiple steel strands 2 can be fixedly connected by the clamping ring 10 and the wire-hanging ring 11 to form a whole.

[0033] One end of the free section 4 of the anchor cable body away from the anchoring section 3 is fixedly connected with an anchor 12, and the anchor 12 can be fixedly connected to the reinforced concrete frame on the surface of the slope, so as to fix the anchor cable.

[0034] The primary grouting pipe 5 is provided with grouting holes 51, and there are multiple grouting holes 51 and they are evenly spaced along the length direction of the primary grouting pipe 5. Therefore, cement mortar can be injected into the anchor hole 1 through the primary grouting pipe 5 to perform primary grouting, and the grouting pressure is 0.4-1MPa. The secondary grouting pipe 6 is provided with a valve body 7, and there are multiple valve bodies 7. The end of the valve body 7 is provided with a grouting outlet 71, and the diameter of the grouting outlet 71 is 8-10mm. The valve body 7 is provided with an adjustment component 8 for controlling the opening and closing of the grouting outlet 71; therefore, after the valve body 7 is opened, cement mortar can be injected again for secondary grouting, and the grouting pressure is 2-5MPa. When installing the valve body 7, the specific positions of the rock interlayers and cracks are determined through geological conditions and drilling construction records, and then the valve body 7 is installed at the corresponding position of the secondary grouting pipe 6. After the anchor cable body together with the primary grouting pipe 5 and the secondary grouting pipe 6 are placed into the anchor cable hole 1, the valve body 7 is located at a position with more cracks in the anchor cable hole 1, thereby achieving the effect of fixed-point grouting, which helps to improve the pull-out bearing capacity of the anchor cable.

[0035] Reference Figure 3 and Figure 4 The valve body 7 is in a hollow cylindrical shape, the interior of the valve body 7 is connected to the interior of the secondary grouting pipe 6, and the length direction of the valve body 7 is perpendicular to the axial direction of the anchor hole 1. There are multiple slurry outlets 71, which are evenly divided into two groups, and each group of slurry outlets 71 is set at one end of the valve body 7. The distance between the end of the valve body 7 and the anchor hole 1 is 1-2cm, so the slurry outlet 71 is close to the hole wall of the anchor hole 1, which can reduce the confining pressure of the primary grouting body and help improve the success rate of secondary pressure grouting.

[0036] The regulating assembly 8 includes a block 81 and a spring 82. There are multiple blocks 81, and the number of the blocks 81 is the same as the number of the slurry outlets 71, and each block 81 corresponds to a slurry outlet 71. The slurry outlet 71 is a round hole, and the block 81 is cylindrical. The diameter of the block 81 is the same as the diameter of the slurry outlet 71, and the block 81 is slidably penetrated in the slurry outlet 71. The length of the block 81 is greater than the depth of the slurry outlet 71, so that one end of the block 81 is located inside the valve body 7, and the other end of the block 81 is located outside the valve body 7. The number of the springs 82 is the same as the number of the blocks 81, and each spring 82 corresponds to a block 81; the spring 82 is sleeved on the outside of the block 81, and the spring 82 is connected between the block 81 and the outer wall of the valve body 7. Under normal conditions, the spring 82 is at its original length, the blocking block 81 is located at the slurry outlet 71, the blocking block 81 blocks the slurry outlet 71, and the valve body 7 is in a closed state; when slurry is introduced into the secondary grouting pipe 6, the slurry can push the blocking block 81 to move to the outside of the valve body 7, so that the slurry outlet 71 is opened, thereby performing secondary grouting.

[0037] Among them, the blocking block 81 is fixedly connected to a limiting block 812 on one side outside the valve body 7. The limiting block 812 is annular, so that the limiting block 812 can limit the movement of the blocking block 81 to prevent the slurry outside the valve body 7 from exerting pressure on the blocking block 81 during a grouting process, causing the blocking block 81 to slide into the inside of the valve body 7, thereby causing the slurry outlet 71 of the valve body 7 to be blocked.

[0038] Furthermore, a conical surface 811 is provided at one end of the block 81 outside the valve body 7, thereby reducing the resistance encountered by the block 81 during its sliding toward the outside of the valve body 7, facilitating the smooth sliding of the block 81, and thus facilitating the smooth progress of the secondary grouting process.

[0039] Reference Figure 4 A connecting piece 13 is fixedly connected between two adjacent limit blocks 812 at the same end of the valve body 7. The connecting piece 13 connects the multiple limit blocks 812 into a whole, so that the multiple block blocks 81 at the same end can move synchronously. Limiting components 9 are provided at both ends of the valve body 7. The limiting components 9 include a rack 93, a ratchet 91 and a torsion spring 92. The rack 93 is fixedly connected to the connecting piece 13, and the rack 93 is arranged along the length direction of the valve body 7; the ratchet 91 is hinged on the outer wall of the valve body 7, and the torsion spring 92 is connected between the ratchet 91 and the valve body 7. The torsion spring 92 is in a twisted state, so that the torsion spring 92 makes the tip of the ratchet 91 press against the teeth of the rack 93. Therefore, when the block 81 moves toward the outside of the valve body 7, the block 81 drives the rack 93 to slide through the connecting piece 13, and the pawl 91 can rotate to avoid it when the rack 93 slides; when the rack 93 tends to slide toward the inside of the valve body 7, the pawl 91 presses against the rack 93, so that the sliding of the rack 93 is restricted, so that the rack 93 can only slide in one direction, so that the block 81 can only slide toward the outside of the valve body 7. Therefore, after the block 81 slides to the outside of the valve body 7, the block 81 is restricted in the current position, so that the slurry outlet 71 is in a continuously open state, which helps the slurry to flow out smoothly during the secondary grouting process.

[0040] Further, refer to Figure 3 A protective shell 14 is fixedly connected to the outer wall of the valve body 7. The protective shell 14 covers the outer sides of the rack 93 and the pawl 91. The protective shell 14 is provided with an avoidance groove 141 for sliding of the connection between the rack 93 and the connecting piece 13. Therefore, the protective shell 14 can reduce the slurry entering the meshing place between the rack 93 and the pawl 91, which helps to ensure the normal operation of the limiting component 9.

[0041] Reference Figure 2, connecting pipes 72 are arranged on opposite sides of the outer wall of the valve body 7, the two connecting pipes 72 are arranged coaxially, and the connecting pipes 72 are connected to the inside of the valve body 7. An internal thread is arranged on the inner wall of the connecting pipe 72, and an external thread is arranged on the outer wall of the connection between the secondary grouting pipe 6 and the connecting pipe 72, so that the connecting pipe 72 and the secondary grouting pipe 6 can be threadedly connected, and the connection process is simple; therefore, it is convenient to select a suitable installation position of the valve body 7 according to needs, and quickly install the valve body 7 on the secondary grouting pipe 6.

[0042] The connection between the connecting pipe 72 and the secondary grouting pipe 6 is coated with sealant, thereby enhancing the sealing and reducing the seepage of slurry there, thereby ensuring the internal pressure of the secondary grouting pipe 6, so that the slurry in the secondary grouting pipe 6 can flow out through the valve body 7.

[0043] The implementation principle of a fixed-point pressure grouting structure of a soft rock prestressed anchor cable in an embodiment of the present application is as follows: the anchor cable body, the primary grouting pipe 5 and the secondary grouting pipe 6 are connected, and then placed together in the anchor cable hole 1; then cement mortar is introduced into the primary grouting pipe 5, and the grouting pressure is 0.4-1MPa, and the cement mortar is injected into the anchor cable hole 1 through the grouting hole 51; wait for two hours, and after the cement mortar in the anchor cable hole 1 is initially solidified, cement mortar is introduced into the secondary grouting pipe 6, and the grouting pressure is 2-5MPa. Under the action of the mortar, the block 81 is pushed to the outside of the valve body 7, so that the slurry outlet 71 is opened, and then the mortar flows into the anchor cable hole 1 through the slurry outlet 71. The mortar fills the interlayers and cracks of the rock strata, and at the same time extends upward and downward, compacting the gap between the primary grouting body and the wall of the anchor cable hole 1, thereby achieving the effect of improving the pull-out friction.

[0044] The above are optional embodiments of the present application, and are not intended to limit the protection scope of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A soft rock prestressed anchor fixed-point pressure grouting structure, arranged in an anchor hole (1), characterized in that: The invention comprises a steel strand (2), a primary grouting pipe (5), a secondary grouting pipe (6) and a valve body (7), wherein the primary grouting pipe (5) is provided with a grouting hole (51), the valve body (7) is arranged on the secondary grouting pipe (6), a grouting outlet (71) is arranged on the valve body (7), and an adjusting component (8) for controlling the opening and closing of the grouting outlet (71) is arranged on the valve body (7).

2. A soft rock prestressed anchor fixed-point pressure grouting structure according to claim 1, characterized in that: The length direction of the valve body (7) is perpendicular to the axial direction of the anchor cable hole (1).

3. A soft rock prestressed anchor fixed-point pressure grouting structure according to claim 2, characterized in that: A plurality of slurry outlets (71) are provided, and the slurry outlets (71) are divided into two groups. The two groups of slurry outlets (71) are respectively located at two ends of the valve body (7).

4. A soft rock prestressed anchor fixed-point pressure grouting structure according to claim 3, characterized in that: The regulating assembly (8) comprises a block (81) and a spring (82); the number of the block (81) is the same as the number of the slurry outlets (71), and each of the block (81) corresponds to a slurry outlet (71); the block (81) is slidably arranged at the corresponding slurry outlet (71); a limit block (812) is arranged on one side of the block (81) outside the valve body (7); and the spring (82) is connected between the block (81) and the valve body (7).

5. A soft rock prestressed anchor fixed-point pressure grouting structure according to claim 4, characterized in that: A conical surface (811) is provided at one end of the blocking block (81) located outside the valve body (7).

6. The soft rock prestressed anchor fixed-point pressure grouting structure according to claim 4, characterized in that: A limiting assembly (9) is provided between the blocking block (81) and the valve body (7), the limiting assembly (9) comprising a ratchet (91), a torsion spring (92) and a rack (93), the rack (93) being provided on the blocking block (81), the ratchet (91) being rotatably provided on the valve body (7), the torsion spring (92) being connected between the ratchet (91) and the valve body (7), the torsion spring (92) causing one end of the ratchet (91) to press against the rack (93).

7. The soft rock prestressed anchor fixed-point pressure grouting structure according to claim 1, characterized in that: The valve body (7) is provided with a connecting pipe (72), the connecting pipe (72) is connected to the interior of the valve body (7), and the connecting pipe (72) is threadedly connected to the secondary grouting pipe (6).

8. The soft rock prestressed anchor fixed-point pressure grouting structure according to claim 7, characterized in that: A sealant is provided between the connecting pipe (72) and the secondary grouting pipe (6).

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