Bag type jet grouting anchor rod structure

Abstract

The utility model discloses a bag type rotary jet grouting anchor rod structure which comprises an anchor rod assembly extending into an anchor rod hole and cement soil wrapping the anchor rod assembly, and the anchor rod hole is formed through the rotary jet grouting technology. The anchor rod assembly comprises an anchor cable set and two anchor disc assemblies, the two ends of the bag are each connected with one anchor disc assembly, the two ends of the steel cylinder are each connected with one anchor disc assembly, a bag containing cavity is formed between the steel cylinder and the bag, and an anchoring block formed by cement paste is arranged in the bag containing cavity. Each anchor cable of the anchor cable group is fixed on an anchor disc assembly; the jet grouting drill rod can abut against the anchor disc assembly, and the anchor rod assembly is fed into the anchor rod hole. The grouting pipe and the exhaust pipe are communicated with the bag containing cavity. According to the method, collapse of the anchor rod hole is avoided through the cement soil in the anchor rod hole, the surrounding soil body is compacted through the cement paste, and the strength of the surrounding soil body of the anchor rod hole is improved.

Description

Technical Field

[0001] The utility model relates to a capsule type rotary grouting anchor rod structure. Background Art

[0002] During the construction of the bladder-type enlarged head anchor rod, a drilling machine is first used to adopt dry construction to form the anchor rod hole, and then part of the anchor rod hole is enlarged to form the enlarged head cavity. The anchor rod steel structure is placed into the anchor rod hole, and finally cement slurry is injected into the bladder and the anchor rod hole. After the cement slurry solidifies and reaches the set strength, the anchor rod steel structure is tensioned to generate prestress.

[0003] In actual construction, the soil in the anchor hole cannot be completely cleaned, especially a certain amount of soil will remain in the enlarged head cavity, and in the process of the anchor steel structure entering the anchor hole, due to the contact of the anchor steel structure and the collapse of some anchor holes themselves, there is more soil in the anchor hole, and the bag structure is difficult to push in. When grouting into the bag, the bag cannot be completely opened, which affects the outer diameter of the bag-type enlarged head and reduces the pull-out bearing capacity of the bag-type enlarged head anchor.

[0004] In addition, due to the small friction and adhesion between the bladder and the underground soil, the anchor rod mainly relies on the end face resistance of the bladder-type enlarged head to improve the pull-out bearing capacity, which limits the scope of use of the bladder-type enlarged head anchor rod structure. Utility Model Content

[0005] In order to solve the problems in the prior art of difficulty in inserting the bladder bag into the anchor hole, as well as the low friction and bonding force between the bladder bag and the underground soil, which affect the pull-out bearing capacity of the bladder-type enlarged head anchor structure, the present application proposes a bladder-type rotary grouting anchor structure, which includes an anchor assembly extending into the anchor hole and cement soil wrapped around the anchor assembly, and the anchor hole is formed by a rotary grouting process;

[0006] The anchor assembly comprises an anchor cable group and two anchor plate assemblies, the two anchor plate assemblies are arranged at intervals along the extension direction of the anchor cable hole; the anchor cable group has a plurality of anchor cables, and the plurality of anchor cable groups are arranged at intervals around a central axis, and the two ends of each anchor cable are respectively formed with a pull-out end and a tensioning end, the pull-out end is located in the enlarged head cavity of the anchor cable hole, and the tensioning end extends outward from the anchor cable hole; the two anchor plate assemblies are respectively a first anchor plate assembly and a second anchor plate assembly, wherein the second anchor plate assembly is located on the side of the first anchor plate assembly away from the tensioning end, the bladder is located in the enlarged head cavity, and the two ends of the bladder are respectively sealed and connected to one anchor plate assembly, and the two ends of the steel cylinder are respectively sealed and connected to one anchor plate assembly, a bladder cavity is formed between the steel cylinder and the bladder, and an anchor block formed by cement slurry is provided in the bladder cavity; each anchor cable of the anchor cable group is fixed to the second anchor plate assembly after passing through the inner cavity of the steel cylinder;

[0007] A first center hole is provided on the first anchor plate assembly, and the jet grouting drill rod can pass through the first center hole and then press against the second anchor plate assembly to deliver the anchor rod assembly into the anchor rod hole;

[0008] A grouting pipe and an exhaust pipe are installed on the steel cylinder. Both ends of the grouting pipe and the exhaust pipe are connected to the bladder cavity and the inner cavity of the steel cylinder respectively. One end of the grouting pipe can be sealedly connected to the grouting pipe, and the other end of the grouting pipe can extend outward from the anchor hole; one end of the exhaust pipe can be sealedly connected to the exhaust pipe, and the other end of the exhaust pipe can extend outward from the anchor hole. The inlet of the exhaust pipe in the bladder cavity is located on the side of the steel cylinder adjacent to the first anchor plate assembly. The exhaust pipe is preferably installed on the end of the steel cylinder adjacent to the first anchor plate assembly, as close to the first anchor plate assembly as possible. When the anchor hole is in an inclined state, the inlet of the exhaust pipe is located on the upper side of the steel cylinder, as close to the first anchor plate assembly as possible.

[0009] In the present application, the anchor hole is formed using a rotary jet grouting process. Cement soil, formed by mixing cement slurry with soil, remains within the anchor hole. The supporting force of the cement soil prevents the anchor hole from collapsing. Furthermore, during construction of the anchor hole, the cement slurry seeps outward into the soil surrounding the anchor hole, compacting the soil and increasing the strength of the soil surrounding the anchor hole, effectively preventing the anchor hole from collapsing. When injecting cement slurry into the bladder cavity to form the anchor block, this process must be completed before the cement soil within the anchor hole has initially set, thereby utilizing the fluidity of the cement soil. The cement soil within the anchor hole also forms a cement soil shell around the bladder that bonds the external soil to the bladder. This shell enhances the connection strength between the bladder and the underground soil, thereby increasing the friction between the bladder-type enlarged head and the underground soil, and improving the pullout bearing capacity of the anchor structure. This avoids the drawback of the prior art, where the friction between the bladder-type enlarged head and the underground soil is low, and the pullout bearing capacity is primarily increased by relying on the end resistance of the bladder-type enlarged head. In addition to being used for installing the bladder bag, the two anchor plate assemblies can also improve the connection strength between the anchor rod assembly and the bladder enlarged head.

[0010] In existing construction, the anchor rod assembly is manually pushed into the anchor rod hole using fine-rolled threaded steel bars, which is a static press-in method. Since the fine-rolled threaded steel bars are slender and have a small pushing force, if there is a lot of crushed soil remaining in the anchor rod hole, it cannot be pushed in. The anchor rod assembly can only be pulled out and the anchor rod hole can be cleaned again. During the construction, since the hole collapse phenomenon will occur during the cleaning process, it is often necessary to repeatedly clean it before the anchor rod assembly can be inserted to the set depth. In this application, the anchor rod assembly is inserted into the anchor rod hole using a rotary jet drill rod, which has a large thrust and can overcome the resistance of the cement soil in the anchor rod hole. In addition, when the rotary jet drill rod pushes the anchor rod assembly forward, the rotary jet drill rod needs to keep rotating, so the anchor rod assembly has a good positioning ability.

[0011] Specifically, to facilitate the removal and recycling of the grouting pipe and the exhaust pipe, one end of the grouting pipe can be sealedly inserted into the grouting pipe, and the grouting pipe can be pulled outward to separate the grouting short pipe; one end of the exhaust pipe can be sealedly inserted into the exhaust pipe, and the exhaust pipe can be pulled outward to separate the exhaust short pipe. Preferably, a sealing member such as a sealing ring is used to seal between the grouting pipe and the grouting pipe, and between the exhaust pipe and the exhaust pipe, and the grouting pipe is connected to the grouting pipe and the exhaust pipe is connected to the exhaust pipe by plugging. While ensuring sealing, it is also convenient to recover the grouting pipe and the exhaust pipe.

[0012] Furthermore, in order to improve the stability of the anchor rod assembly when inserted into the anchor rod hole and reduce the resistance of cement soil, a guide cap is fixedly installed on the side of the second anchor plate assembly away from the first anchor plate assembly, and a second center hole connecting the inner cavity of the guide cap and the inner cavity of the steel cylinder is opened on the second anchor plate assembly.

[0013] Specifically, to ensure that the second anchor plate assembly remains stably on the anchor cable and to avoid damage to the anchor cable, the second anchor plate assembly includes an anchor plate and an extrusion plate. For each anchor cable, a through-hole anchor hole is provided on the anchor plate. The end of the anchor hole facing away from the tensioning end is formed into a conical hole with the smaller end facing the tensioning end. A clip group is arranged in the conical hole. The extrusion plate is located on the side of the anchor plate facing away from the tensioning end. A locking bolt connects the extrusion plate to the anchor plate, and the extrusion plate tightly squeezes the clips in the clip group into the conical hole, securing the anchor cable to the anchor plate. The clip-type anchor is a conventional anchor for anchor cables. This method can avoid the use of welding or other methods that affect the strength of the anchor cable to install the second anchor plate assembly.

[0014] Furthermore, corresponding to each anchor cable, an extrusion tube is provided between the anchor plate and the extrusion plate. The extrusion tube is sleeved on the corresponding anchor cable, and the two ends of the extrusion tube are respectively pressed against the clamp and the extrusion plate. In actual construction, the clamp may be completely accommodated in the conical hole. In this case, the clamp cannot be tightly pressed into the conical hole by relying solely on the compression plate, which may easily lead to insufficient locking force of the clamp on the anchor cable. As a result, during the subsequent prestressing, the anchor cable may fall out of the anchor hole, and the prestressing cannot be completed. Using a compression tube to eliminate the above problem can ensure that the clamp can tightly lock the anchor cable to the lower anchoring part.

[0015] Furthermore, a cement-soil expansion head is provided on the side of the bladder facing the tensioning end. The diameter of the cement-soil expansion head is larger than that of the free section and is connected to the bladder. During the formation of the cement-soil expansion head, cement slurry diffuses outward into the surrounding soil, increasing the connection strength between the cement-soil expansion head and the underground soil, thereby improving the stability of the cement-soil expansion head underground. The cement-soil expansion head and the bladder expansion head together form the expansion head section of the anchor structure, enhancing the stability of the bladder expansion head underground and expanding the range of its use.

[0016] Specifically, to ensure the stability of the cement soil enlarged head underground, the outer diameter of the cement soil enlarged head is 0.8-1.2 times the outer diameter of the anchor block.

[0017] Specifically, the cement soil enlarged head is formed by a rotary jet drill rod using a rotary jet process. Utilizing the hole enlarging and grouting functions of the rotary jet drill rod, the required accommodation space for the cement soil enlarged head and the cement soil filling the accommodation space are completed at one time, thereby improving construction efficiency.

[0018] The steps of the construction method of the capsule type rotary grouting anchor structure in this application are as follows:

[0019] (1) drilling an anchor hole using a jet grouting drill rod of a jet grouting drill, and forming an enlarged head cavity at a set position; when drilling the anchor hole, spraying a first cement slurry outward through the jet grouting drill rod, and the first cement slurry forms cement soil with the soil;

[0020] When drilling anchor holes, first use a grouting pressure of 10-15 MPa to form the hole, and then use a grouting pressure of 25-35 MPa to form the expanded head cavity; the water-cement ratio of the first cement slurry is 1.0-1.5;

[0021] (2) After the drilling of the anchor hole is completed, the jet grouting drill rod is pulled out of the anchor hole, and then the head of the jet grouting drill rod is passed through the first center hole and pressed against the edge of the second center hole. The anchor assembly carrying the grouting pipe and the exhaust pipe is inserted into the anchor hole using the jet grouting drill rod, and the bag is located in the expanded head cavity;

[0022] (3) injecting a second cement slurry into the bag cavity through the grouting pipe, and the gas in the bag cavity is discharged outward through the exhaust pipe; after the second cement slurry solidifies, it forms an anchor block, and the anchor block and the bag together form a bladder-type enlarged head;

[0023] When injecting the second cement slurry into the bag cavity, the grouting pressure is 4-8 MPa, and the water-cement ratio of the second cement slurry is 0.4-0.6;

[0024] After grouting is completed in the bladder cavity, the jet grouting drill rod is moved outward, and the third cement slurry is injected into the steel cylinder at the same time. When the jet grouting drill rod exceeds the first anchor plate assembly, the third cement slurry is continued to be sprayed to form a cement soil expansion head. The cement soil expansion head and the bladder expansion head together form an expansion head section.

[0025] When grouting into the steel cylinder and constructing the cement soil expansion head, the grouting pressure is 25-35MPa, and the water-cement ratio of the third cement slurry is 1.0-1.5;

[0026] The jet grouting drill pipe sprays at least twice as it forms the cement-soil enlarged head. Grouting into the bag must be completed before the cement-soil in the anchor hole begins to set. Grouting can also be injected into the steel cylinder using a grouting pipe.

[0027] (4) Inject the third cement slurry into the common anchor section and the free section. The grouting pressure in both the common anchor section and the free section is 10-15 MPa;

[0028] (5) When the grout in the anchor hole reaches the set strength, the anchor cable is tensioned and locked. The grout in the anchor hole includes the second cement grout in the bag and the cement soil formed by mixing the first cement grout and the third cement grout with the soil.

[0029] In this application, the water-cement ratio of each cement slurry is the weight ratio of water to cement. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural diagram of an embodiment of the present application.

[0031] Figure 2 yes Figure 1 Enlarged view of part A.

[0032] Figure 3 yes Figure 2 Magnified view of part B.

[0033] Figure 4 yes Figure 3 Magnified view of part C.

[0034] Figure 5 yes Figure 3 Magnified view of part D.

[0035] Figure 6 This is the installation diagram of the guide cap.

[0036] Figure 7 This is a state diagram when the bag cavity is not grouting. DETAILED DESCRIPTION

[0037] The following is an explanation of the bladder type rotary grouting anchor rod structure.

[0038] See also Figures 1-6 Along its length, the bladder jet grouting anchor structure comprises an enlarged head section 201, a conventional anchoring section 202, and a free section 203, which are sequentially connected. The enlarged head section and the conventional anchoring section are collectively referred to as the anchoring section, and the conventional anchoring section and the free section have approximately the same diameter. In this embodiment, the bladder jet grouting anchor structure is inclined. It is understood that in other embodiments, the bladder jet grouting anchor structure can also be vertical or horizontal. In actual construction, there are no specific requirements for the extension direction of the bladder jet grouting anchor structure.

[0039] The bladder type rotary grouting anchor structure comprises an anchor assembly 100 inserted into an anchor hole 200 and cement soil wrapped around the anchor assembly 100. The cement soil is not shown in the drawings. The anchor hole 200 is formed by a rotary grouting process.

[0040] The anchor assembly 100 includes an anchor cable assembly and two anchor plate assemblies, which are spaced apart along the extension direction of the anchor hole. The two anchor plate assemblies are a first anchor plate assembly 20 and a second anchor plate assembly 30, wherein the second anchor plate assembly 30 is located on the side of the first anchor plate assembly 20 away from the tensioning end. The anchor cable assembly includes a plurality of anchor cables 10, which are spaced apart around a central axis. Specifically, in this embodiment, the anchor cable assembly includes four anchor cables 10. Each anchor cable 10 has two ends formed as an anti-pullout end 101 and a tensioning end 102, wherein the anti-pullout end 101 is located within the enlarged head cavity 220 of the anchor hole 200, and the tensioning end 102 extends outward from the anchor hole 200. The bladder 11 is located within the enlarged head cavity 220, and the two ends of the bladder are respectively sealed to an anchor plate assembly.

[0041] The two ends of the steel cylinder 40 are respectively connected to an anchor plate assembly in a sealed manner, and a bladder cavity is formed between the steel cylinder 40 and the bladder 11. The bladder cavity contains an anchor block formed by cement slurry. The anchor block and the bladder together form a bladder-type enlarged head.

[0042] The outer surface of the bag is provided with a shell adjacent to the cement soil. In the present embodiment, the bag is provided with a cement soil enlarged head 230 toward the side of the tensioning end, and the cement soil enlarged head is connected to the bag. Figure 1 In the longitudinal direction, the area of ​​the bladder enlarged head is marked as S, and the area of ​​the cement soil enlarged head 230 is marked as M. The bladder enlarged head and the cement soil enlarged head together form the enlarged head section 201. In this embodiment, the cement soil enlarged head 230 is formed by the jet grouting drill rod 300 using the jet grouting process.

[0043] In this embodiment, the outer diameter of the cement soil enlarged head is the same as the outer diameter of the anchor block. It is understood that in other embodiments, the outer diameter of the cement soil enlarged head can also be 0.8 times, 8.9 times, 1.1 times, or 1.2 times the outer diameter of the anchor block, or other multiples between 0.8 and 1.2 times.

[0044] The following describes the structure of the two anchor plate components. Figure 4 The first anchor plate assembly 20 includes an anchor ring 21 and a first compression ring 13. The first compression ring 13 is located on the side of the anchor ring 21 facing away from the second anchor plate assembly 30. One end of the bladder is held between the anchor ring and the first compression ring. A first compression bolt 14 passes through the first compression ring 13 and is screwed onto the anchor ring, sealingly connecting one end of the bladder to the first anchor plate assembly 20.

[0045] The second anchor plate assembly 30 includes an anchor plate 31, a compression plate 33, and a second compression ring 16. For each anchor cable 10, the anchor plate 31 is provided with a through-hole anchor hole. The end of the anchor hole, facing away from the tensioning end, is formed into a conical hole 35 with the smaller end facing the tensioning end. A clip group 36 is disposed within the conical hole 35. The compression plate 33 is located on the side of the anchor plate facing away from the tensioning end. Locking bolts 34 connect the compression plate to the anchor plate. The compression plate tightly compresses the clips in the clip group 36 within the conical hole, securing the anchor cable to the anchor plate. To ensure compression of the clips in the clip group, a compression tube 32 is sleeved on each anchor cable. The compression tube is located between the clips of the clip group and the compression plate. The compression plate presses against the clips of each clip group through the compression tube.

[0046] The ends of the steel cylinder 40 are welded to the anchor ring 21 and the anchor plate 31, respectively. In this embodiment, each anchor cable 10 passes through the first center hole 211 of the anchor ring and is connected to the second anchor disc assembly 30. The first center hole 211 of the anchor ring also serves as the center hole of the first anchor disc assembly 20, allowing each anchor cable 10 to pass through the center hole of the first anchor disc assembly and then connect to the second anchor disc assembly 30. In other words, each anchor cable 10 passes through the inner cavity of the steel cylinder 40 and is fixedly connected to the second anchor disc assembly 30.

[0047] The second clamping ring 16 is located on the side of the anchor plate 31 away from the first anchor plate assembly, and the other end of the bladder is pressed between the second clamping ring 16 and the anchor plate 31. The second clamping bolt 17 passes through the second clamping ring 16 and is screwed onto the anchor plate to seal the other end of the bladder to the second anchor plate assembly 30.

[0048] When securing the bag, special seals are generally not required. Since the bag is primarily made of organic materials such as HDPE, PVC, or PPTA, it has a certain degree of elasticity and inherently provides a strong seal. If the bag is difficult to install, special connectors can be installed at both ends to facilitate installation. Of course, seals can also be installed if necessary.

[0049] The jet-jet drill rod 300 can pass through the center hole and press against the second anchor plate assembly, inserting the anchor assembly into the anchor hole. In this embodiment, to facilitate positioning of the jet-jet drill rod on the second anchor plate assembly, a second center hole 311 is defined in the center of the anchor plate 31. The end of the jet-jet drill rod can be partially inserted into this second center hole, inserting the anchor assembly into the anchor hole. While the second center hole is a through hole, it is understood that in another embodiment, the second center hole can also be a blind hole opening toward the first anchor plate assembly.

[0050] A grouting pipe 303 and an exhaust pipe 306 are installed on the steel cylinder. Both ends of the grouting pipe 303 and the exhaust pipe 306 are connected to the bag cavity and the inner cavity of the steel cylinder respectively.

[0051] A first pipe joint 304 is provided at one end of the grouting pipe 303 located within the inner cavity of the steel cylinder. One end of the grouting pipe 301 can be inserted into the first pipe joint 304, and the other end of the grouting pipe 301 can extend outward from the anchor hole. A sealing ring is embedded in the inner wall of the first pipe joint, allowing the grouting pipe to be sealedly connected to the grouting pipe 303. In this embodiment, the grouting pipe is inserted into the first pipe joint 304 only via the sealing ring. When the grouting pipe is pulled outward, it can be pulled out of the first pipe joint 304 to disengage the grouting short pipe, thereby allowing the grouting pipe to be pulled out of the anchor hole for recycling. Of course, the first pipe joint 304 can also be inserted into the grouting pipe.

[0052] A second pipe joint 307 is provided at one end of the exhaust pipe 306 located within the inner cavity of the steel cylinder. One end of the exhaust pipe 302 can be inserted into the second pipe joint 307, and the other end of the exhaust pipe 302 can extend outward from the anchor hole. A sealing ring is embedded in the inner wall of the second pipe joint, allowing the exhaust pipe to be sealedly connected to the exhaust pipe 306. In this embodiment, the exhaust pipe is inserted into the second pipe joint 307 only through the sealing ring. When the exhaust pipe is pulled outward, it can be pulled out of the second pipe joint 307 to disengage the exhaust short pipe, thereby removing the exhaust pipe from the anchor hole for recycling. Of course, the second pipe joint 307 can also be inserted into the exhaust pipe.

[0053] To prevent the grouting pipe or exhaust pipe from falling off the grouting connecting pipe or exhaust connecting pipe, the grouting pipe or exhaust pipe can be fixed to the inner wall of the steel cylinder using fixing parts such as welding clamps, but this does not affect the removal of the grouting pipe and exhaust pipe from the anchor hole.

[0054] In this embodiment, the outlet of the anchor hole extends upward in an inclined direction, giving the bladder-type rotary grouting anchor structure an inclined shape. In order to maximize the discharge of gas from the bladder cavity during grouting into the bladder cavity, in this embodiment, the exhaust pipe 306 is installed at the top of the upper side of the steel cylinder, and the inlet of the exhaust pipe in the bladder cavity extends upward and as close as possible to the first anchor plate assembly, but the exhaust of gas cannot be blocked by the anchor plate assembly. There are no specific requirements for the outlet position of the grouting pipe in the bladder cavity, as long as it can smoothly inject cement slurry into the bladder cavity.

[0055] Cement slurry can be injected into the bag cavity through the grouting pipe to form the anchor block 210. During the process of injecting the cement slurry into the bag cavity, the gas in the bag cavity can be discharged from the anchor hole 200 through the exhaust pipe.

[0056] It is understood that in order to reduce the resistance of the anchor assembly when it is inserted into the anchor hole, please refer to Figure 6 In another embodiment, a guide cap 50 may be installed on the second anchor plate assembly. Figure 6 In the installation, the guide cap is welded to the second compression ring 16 and positioned on the side of the anchor plate 31 facing away from the first anchor plate assembly. Once the second compression ring is installed on the anchor plate 31, the guide cap is also installed. To ensure that the guide cap is filled with cement slurry, the second center hole must be a through hole, and preferably, a slurry hole 331 is provided in the extrusion plate.

[0057] Of course, a through hole can also be provided on the guide cap to facilitate the cement soil in the anchor hole to enter the guide cap.

[0058] It is understood that in another embodiment, the guide cap 50 can also be welded to the side of the anchor plate 31 away from the first anchor plate assembly. Of course, the guide cap 50 can also be installed on the anchor plate 31 or the second clamping ring 16 by flange connection or other means.

[0059] To explain this application in more detail, the construction method of the capsule type rotary grouting anchor structure in this embodiment is described below. The steps are as follows:

[0060] (1) An anchor hole is drilled using a jet grouting drill rod of a jet grouting drill, and an enlarged head cavity is formed at a set position. When drilling the anchor hole, a first cement slurry is sprayed outward through the jet grouting drill rod, and the first cement slurry forms cement soil with the soil.

[0061] When drilling an anchor hole, a grouting pressure of 10-15 MPa is first used to create the hole, followed by a grouting pressure of 25-35 MPa to form the enlarged head cavity. The water-cement ratio of the first cement slurry is 1.0-1.5. Specifically, in this embodiment, a grouting pressure of 12 MPa is first used to create the hole, followed by a grouting pressure of 30 MPa to form the enlarged head cavity. The water-cement ratio of the first cement slurry is 1.0.

[0062] (2) After the anchor hole is drilled, the jet grouting drill rod is pulled out of the anchor hole. The head of the jet grouting drill rod is passed through the first center hole 211 and pressed against the edge of the second center hole 311. The jet grouting drill rod is used to insert the anchor assembly with the grouting pipe and the exhaust pipe into the anchor hole, and the bag is located in the expanded head cavity. Figure 7 At this time, under the pressure of cement soil in the anchor hole, the bag is attached to the outer surface of the steel cylinder. Figure 7 In the embodiment, the bladder bag is not attached to the outer peripheral surface of the steel cylinder.

[0063] (3) A second cement slurry is injected into the bag cavity through the grouting pipe, and the gas in the bag cavity is discharged outward through the exhaust pipe; after the second cement slurry solidifies, it forms an anchor block 210, and the anchor block and the bag together form a bladder-type enlarged head.

[0064] When the second cement slurry is injected into the bag cavity, the grouting pressure is 4-8 MPa, and the water-cement ratio of the second cement slurry is 0.4-0.6. Specifically in this embodiment, when the second cement slurry is injected into the bag cavity, the grouting pressure is 5 MPa, and the water-cement ratio of the second cement slurry is 0.5.

[0065] After completing the grouting into the bladder cavity, the jet grouting drill rod is moved outward, and the third cement slurry is injected into the steel cylinder at the same time. When the jet grouting drill rod exceeds the first anchor plate assembly, the third cement slurry is continued to be sprayed to form a cement soil expansion head. The cement soil expansion head and the bladder expansion head together form the expansion head section 201.

[0066] When grouting into the steel cylinder and constructing the cement-soil enlarged head, the grouting pressure is 25-35 MPa, and the water-cement ratio of the third cement slurry is 1.0-1.5. Specifically in this embodiment, when forming the cement-soil enlarged head, the grouting pressure is 30 MPa, and the water-cement ratio of the third cement slurry is 1.2.

[0067] The jet grouting drill pipe sprays at least twice as it forms the cement-soil enlarged head. Grouting into the bag must be completed before the cement-soil in the anchor hole begins to set. Grouting can also be injected into the steel cylinder using a grouting pipe.

[0068] (4) Inject the third cement slurry into the common anchoring section and the free section. The grouting pressure in the common anchoring section and the free section is 10-15 MPa. In this embodiment, the grouting pressure in the common anchoring section and the free section is 12 MPa.

[0069] (5) When the grout in the anchor hole reaches the set strength, the anchor cable is tensioned and locked. The grout in the anchor hole includes the second cement grout in the bag and the cement soil formed by mixing the first cement grout and the third cement grout with the soil.

[0070] In this embodiment, the water-cement ratio of each cement slurry is the weight ratio of water to cement.

Claims

1. A capsule type rotary grouting anchor structure, characterized in that: It includes an anchor rod assembly inserted into an anchor rod hole and cement soil wrapped around the anchor rod assembly, wherein the anchor rod hole is formed by a rotary grouting process; The anchor assembly comprises an anchor cable group and two anchor plate assemblies, the two anchor plate assemblies are arranged at intervals along the extension direction of the anchor cable hole; the anchor cable group has a plurality of anchor cables, and the plurality of anchor cable groups are arranged at intervals around a central axis, and the two ends of each anchor cable are respectively formed with a pull-out end and a tensioning end, the pull-out end is located in the enlarged head cavity of the anchor cable hole, and the tensioning end extends outward from the anchor cable hole; the two anchor plate assemblies are respectively a first anchor plate assembly and a second anchor plate assembly, wherein the second anchor plate assembly is located on the side of the first anchor plate assembly away from the tensioning end, the bladder is located in the enlarged head cavity, and the two ends of the bladder are respectively sealed and connected to one anchor plate assembly, and the two ends of the steel cylinder are respectively sealed and connected to one anchor plate assembly, a bladder cavity is formed between the steel cylinder and the bladder, and an anchor block formed by cement slurry is provided in the bladder cavity; each anchor cable of the anchor cable group is fixed to the second anchor plate assembly after passing through the inner cavity of the steel cylinder; A first center hole is provided on the first anchor plate assembly, and the jet grouting drill rod can pass through the first center hole and then press against the second anchor plate assembly to deliver the anchor rod assembly into the anchor rod hole; A grouting pipe and an exhaust pipe are installed on the steel cylinder, and both ends of the grouting pipe and the exhaust pipe are respectively connected to the bag cavity and the inner cavity of the steel cylinder. One end of the grouting pipe can be sealedly connected to the grouting pipe, and the other end of the grouting pipe can extend outward from the anchor hole; one end of the exhaust pipe can be sealedly connected to the exhaust pipe, and the other end of the exhaust pipe can extend outward from the anchor hole. The inlet of the exhaust pipe in the bag cavity is located on the side of the steel cylinder adjacent to the first anchor plate assembly.

2. The bladder type rotary grouting anchor structure according to claim 1, characterized in that: One end of the grouting pipe can be sealed and inserted into the grouting connecting pipe. By pulling the grouting pipe outward, the grouting pipe can be separated from the grouting short pipe. One end of the exhaust pipe can be sealed and inserted into the exhaust connecting pipe. By pulling the exhaust pipe outward, the exhaust pipe can be separated from the exhaust short pipe.

3. The bladder type rotary grouting anchor structure according to claim 1, characterized in that: A guide cap is fixedly installed on one side of the second anchor disc assembly away from the first anchor disc assembly, and a second central hole communicating with the inner cavity of the guide cap and the inner cavity of the steel cylinder is opened on the second anchor disc assembly.

4. The bladder type rotary grouting anchor structure according to claim 1, characterized in that: The second anchor plate assembly includes an anchor plate and an extrusion plate. Corresponding to each anchor cable, an anchor hole in the shape of a through hole is provided on the anchor plate. The end of the anchor hole away from the tensioning end is formed into a conical hole with the small end facing the tensioning end. A clip group is arranged in the conical hole. The extrusion plate is located on the side of the anchor plate away from the tensioning end. The locking bolt connects the extrusion plate to the anchor plate, and the extrusion plate tightly squeezes the clips in the clip group into the conical hole to fix the anchor cable on the anchor plate.

5. The bladder type rotary grouting anchor structure according to claim 4, characterized in that: Corresponding to each anchor cable, an extrusion tube is provided between the anchor plate and the extrusion plate. The extrusion tube is sleeved on the corresponding anchor cable, and the two ends of the extrusion tube are respectively pressed against the clamping piece and the extrusion plate.

6. The bladder type rotary grouting anchor structure according to claim 1, characterized in that: A cement soil enlarged head is provided on one side of the bladder bag facing the tensioning end. The diameter of the cement soil enlarged head is larger than the diameter of the free section, and the cement soil enlarged head is connected to the bladder bag.

7. The bladder-type rotary grouting anchor structure according to claim 6, characterized in that: The outer diameter of the cement soil enlarged head is 0.8-1.2 times the outer diameter of the anchor block.

8. The bladder-type jet-grouting anchor structure according to claim 6, characterized in that: The cement soil enlarged head is formed by a rotary grouting drill rod using a rotary grouting process.

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