Recyclable rotary jet enlarged head anchor cable and construction method

Abstract

The present invention discloses a recyclable rotary jet enlarged head anchor cable and a construction method, comprising a rotary jet drill bit, a locking and recovery device, a recyclable anchor cable, a drill rod, a protective casing, and a prestressed steel strand. The rotary jet drill bit and the recyclable anchor cable are mounted on the locking and recovery device, which is mounted on the drill rod. The recyclable anchor cable is connected to the prestressed steel strand, which is connected to the locking and recovery device and the protective casing, through which the prestressed steel strand passes. The present invention allows the locking and recovery device and the protective casing to form a sealed space for the prestressed steel strand, which is not affected by the various strands of prestressed steel strand, thereby improving the reliability of recovery and providing a better unlocking and recovery effect. The locking and recovery device has a simple structure, a large anchoring force, and is suitable for large-scale production with a high cost-effectiveness ratio. Locking and releasing the recyclable anchor cable are simpler, and manual recovery is easy to operate and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of anchor cables, and in particular to a recyclable rotary jet enlarged head anchor cable and a construction method. Background Art

[0002] In construction foundation pit projects, cast-in-place piles and anchor cables are often used in deep foundation pit support. Anchor cables are usually relatively long and may go beyond the red line, which may affect future subway shield construction and reduce underground pollution. Recyclable anchor cables are often used in design and construction. After the main structure is completed and the support is replaced, the anchor cables previously set in the underground soil are recycled, and the steel strands are recycled, which can reduce costs and meet the requirements of low-carbon environmental protection.

[0003] The pull-out resistance of the anchor cable is provided by the friction between the anchor section and the surrounding soil. In some projects, due to the thick silt layer, sand layer or silty clay in the stratum and the deep buried rock layer, when the anchor cable is used as the foundation pit support structure, the anchor cable of the stratum must be very long; some projects are surrounded by buildings, and the anchor cable will enter the stratum under the basement of the surrounding buildings, which may affect the original project piles and cause unnecessary disputes; if the pull-out resistance of the ordinary anchor cable with reduced length cannot meet the design requirements, at this time, the use of enlarged head anchor cable can greatly reduce the length of the anchor section of the anchor cable, which can solve the above problems.

[0004] In actual use, since the recyclable anchor cable may be tens of meters or even hundreds of meters, the currently disclosed recyclable anchor cable recovery method usually requires rotating the anchor cable from the tensioning end of the anchor cable waist beam, or pressing the anchor cable into the positioning unlocking device, so as to unlock the anchor cable from the anchor end in the soil, release the steel strand at the anchor end, and achieve the recovery of the anchor cable; because the anchor cable has great flexibility and elasticity and length, the anchor cable is affected by the friction resistance of the sheath, as well as the effect of its own flexibility and elasticity, and the force of the anchor cable rotation or thrust is difficult to transmit The force when it reaches the other end or is transmitted is very small; when a large tonnage is tensioned, the greater tensioning force locks the anchor cable tightly at the anchor end. The anchor clamping piece at the anchor end in the soil has a greater locking force on the anchor cable, and the rotation and pushing force for unlocking also needs to be greater. The rotation and pushing force of the anchor cable through the tensioning section cannot overcome the locking force of the anchor clamping piece, and the anchor cable cannot be rotated or pushed at all, which makes it impossible to unlock, resulting in failure of anchor cable recovery; the longer the anchor cable is, the greater the tensioning lock or actual force tonnage, the higher the risk of failure of anchor end unlocking and failure of anchor cable recovery.

[0005] The currently disclosed recyclable enlarged head anchor cable has a fully enclosed conical sleeve on the outside of the pressure plate of the anchor end of the soil body and is made into a conical head. The recyclable enlarged head anchor cable is a pressure or pressure dispersion type; although the anchor section at the bottom of the hole is exceeded during grouting or jet grouting, the jet grouting drill pipe nozzle is directly pressed into the conical head after the anchor cable is lowered, and the jet grouting does not exceed the anchor end again. When reaching the bottom of the hole, the anchor end (conical head) is not necessarily located at the center of the jet grouting enlarged head pile. As the drill pipe is withdrawn, the anchor cable as a whole may slide downward a little, so that the direct bonding between the anchor end and the jet grouting enlarged cement soil body has the risk of defects such as voids and incompleteness, resulting in defects in the anchor end pressure plate and the enlarged head anchor section, thereby affecting the tensioning force of the recyclable enlarged head anchor cable.

[0006] The currently disclosed retrievable anchor cables have a fairing or a cone sleeve wrapped in the anchor end recovery device and are interconnected internally. When the recovery device or steel strand protective sleeve of a certain anchor cable is filled with cement slurry, all of the anchor cables will be filled with cement slurry due to the interconnection. The recovery device or protective rubber sleeve will be filled with cement slurry, making it impossible to pull out the anchor cable, affecting the recovery of the entire anchor cable. With a single pressure plate, the anchoring force will be limited, and the tensile material properties of the steel strand cannot be fully utilized. Summary of the Invention

[0007] The purpose of the present invention is to overcome the deficiencies of the above-mentioned prior art and to provide a recyclable rotary grouting enlarged head anchor cable and a construction method.

[0008] The purpose of the present invention is achieved through the following technical solutions: a recyclable rotary jet enlarged head anchor cable, comprising a rotary jet drill bit, a locking recovery device, a recyclable anchor cable, a drill rod, a protective casing and a prestressed steel strand, the locking recovery device comprising a pressure cover plate, a pressure anchor plate, a bolt, a locking structure, a release structure and a rotating pressure bearing, the rotary jet drill bit is mounted on the pressure anchor plate through the rotating pressure bearing, one end of the rotary jet drill bit passes through the pressure anchor plate and the pressure cover plate in sequence, the other end of the rotary jet drill bit is connected to the drill rod, The retrievable anchor cable is installed on the pressure anchor plate through one end of the locking structure, one end of the release structure is respectively connected to one end of the retrievable anchor cable and the locking structure, the other end of the release structure is connected to the pressure cover plate, the other end of the retrievable anchor cable is connected to one end of the prestressed steel strand, one end of the protective sleeve is connected to the pressure anchor plate, the other end of the prestressed steel strand and the other end of the locking structure are both protruded from the other end of the protective sleeve, and the pressure cover plate is connected to the pressure anchor plate by bolts.

[0009] A better choice is that the release structure includes a steel sleeve tube, a spring, a positioning receiving block, a catheter and a locking buckle. The two ends of the steel sleeve tube are respectively connected to the pressure cover plate and the pressure anchor plate. The positioning receiving block is installed on the inner wall of the steel sleeve tube through the catheter. The catheter is installed on the pressure cover plate through the locking buckle. One end of the positioning receiving block matches the locking buckle. The other end of the positioning receiving block is connected to one end of the recyclable anchor cable through a guide connecting line. The other end of the positioning receiving block is connected to the locking structure through a spring.

[0010] A better choice is that the positioning receiving block includes a self-locking joint, a guide cylinder and a connecting part connected in sequence, the self-locking joint matches the locking buckle, the guide cylinder is movably installed on the catheter, the connecting part is connected to the guide connecting line, and the guide cylinder is connected to the spring.

[0011] A better choice is that the locking structure includes a guide anchor protective tube, a pinning steel wire, a connecting tube and an anchor clamping plate, the pressure anchor plate is provided with a plurality of conical seat sleeves, and the plurality of conical seat sleeves are distributed around the rotary jet drill bit, the recoverable anchor cable is installed on the conical seat sleeve through the anchor clamping plate, the connecting tube is communicated with the conical seat sleeve, the connecting tube is installed on the guide anchor protective tube, the guide anchor protective tube is installed on the protective sleeve, the other end of the recoverable anchor cable passes through the connecting tube and is connected to one end of the prestressed steel strand, one end of the pinning steel wire is clamped between the conical seat sleeve and the anchor clamping plate, and the other end of the pinning steel wire passes through the connecting tube, the guide anchor protective tube and the protective sleeve in sequence.

[0012] A better option is that the jet grouting drill bit is provided with two high-pressure nozzles, one of the high-pressure nozzles is located on the side of the pressure cover plate away from the pressure anchor plate, and the other high-pressure nozzle is located between the pressure cover plate and the pressure anchor plate.

[0013] A better option is that the bolt includes a nut and a fixing screw, one end of the fixing screw passes through the pressure cover plate and is connected to a nut, and the other end of the fixing screw passes through the pressure anchor plate and is connected to another nut.

[0014] A construction method for a recyclable rotary grouting enlarged head anchor cable comprises the following steps:

[0015] S1. According to the design requirements of elevation and horizontal spacing, set the location of the drilling hole in the foundation pit, and trim the drilling rig working soil platform according to the location of the drilling hole;

[0016] S2, installing an anchor drilling rig on the drilling rig working soil platform of step S1, installing a rotary jet drill bit on the drill rod of the anchor drilling rig, aligning the rotary jet drill bit with the drilling position and drilling until the rotary drill bit reaches the junction of the conventional anchoring section and the enlarged head anchoring section, then stopping the drilling, and completing the construction of the conventional anchoring section;

[0017] S3. Turn on the high-pressure pump to supply cement slurry to the jet grouting drill bit. The jet grouting drill bit starts to rotate. The cement slurry jets and cuts the soil to form a large-diameter cement-soil cylindrical pile. Turn on the grouting mode of the jet grouting drill bit to grout the large-diameter cement-soil cylindrical pile, completing the construction of the enlarged head anchoring section.

[0018] S4. Pull the drill rod and the jet grouting drill bit out of the borehole, then remove the jet grouting drill bit from the drill rod, install the jet grouting drill bit and the recyclable anchor cable on the locking and recovery device, and then install the locking and recovery device on the drill rod;

[0019] S5. Use a jet grouting drill bit to push the expanded head anchoring section, start the high-pressure pump, and the high-pressure pump will deliver cement slurry to the jet grouting drill bit. The jet grouting drill bit starts to rotate, and the cement will be jetted and cut into the soil. The diameter of the expanded head anchoring section is increased, and the cement slurry is simultaneously filled in the expanded head anchoring section, completing the secondary grouting of the expanded head anchoring section.

[0020] S6. The prestressed steel strand is tensioned in the tensioning section. The prestressed steel strand drives the recyclable anchor cable to be tensioned. The recyclable anchor cable is locked by the clamping anchor sheet and the conical seat sleeve.

[0021] S7. The recyclable anchor cable is recovered from the locking recovery device.

[0022] A better option is that step S6 includes the following steps:

[0023] S601, performing the first tensioning of each prestressed steel strand according to 30% of the design tensioning force of the prestressed steel strand;

[0024] S602. Then, the entire prestressed steel strand is tensioned for the second time according to the designed tensioning force of the recyclable anchor cable. The recyclable anchor cable drives the positioning receiving block to approach the conical seat sleeve through the guide connecting line. The positioning receiving block presses the clamping anchor piece through the spring. At the same time, the recyclable anchor cable drives the clamping anchor piece to press the conical seat sleeve to lock it.

[0025] A better option is that step S7 includes the following steps:

[0026] S701. Use a jack to pull the pinning wire out from between the conical seat sleeve and the clamping anchor piece, so that the locking force of the clamping anchor piece and the conical seat sleeve on the recyclable anchor cable is reduced or eliminated.

[0027] S702. Rotate the anchor cable and push it into the conical seat sleeve. The anchor cable pushes the positioning receiving block toward the lock buckle through the spring. The positioning receiving block is automatically connected to the self-locking joint and the lock buckle. At the same time, the spring drives the anchor clamping piece to detach from the conical seat sleeve. The recyclable anchor cable is pulled outward from the conical seat sleeve. The recyclable anchor cable is sequentially detached from the anchor clamping piece, the conical seat sleeve and the anchor guide tube, completing the recovery of the recyclable anchor cable.

[0028] The present invention has the following advantages and beneficial effects compared to the prior art:

[0029] 1. The present invention uses a rotary jet drill bit, a locking and recovery device, a recyclable anchor cable, a drill rod, a protective casing and a prestressed steel strand. The locking and recovery device and the protective casing form a closed space for the prestressed steel strand, and each strand of the prestressed steel strand is not affected, thereby improving the reliability of recovery; its unlocking and recovery effect is better, the locking and recovery device has a simple structure, a large anchoring force, and is mass-produced with a high cost-effectiveness; locking and releasing the recyclable anchor cable is simpler, and manual recovery is easy to operate and reliable.

[0030] 2. The present invention overcomes the defect of bonding between the anchoring end of the anchor cable and the cement slurry of the rotary grouting enlarged head through a construction method of a recyclable rotary grouting enlarged head anchor cable. The locking recovery device is more tightly combined with the cement slurry, which can ensure the anchoring force of the anchor cable. The anchoring force is large, the force transmission is reliable, and a large-tonnage anchoring tension force can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of a locking and recovery device for a recyclable rotary jet enlarged head anchor cable according to the present invention;

[0032] Figure 2 This is a cross-sectional view of a pressure anchor plate of a locking and recovery device for a recoverable rotary jet enlarged head anchor cable according to the present invention;

[0033] Figure 3 This is a cross-sectional view of a locking and recovery device for a recoverable rotary jet enlarged head anchor cable according to the present invention;

[0034] Figure 4 Schematic diagram of unlocking a recyclable anchor cable of a locking and recovery device for a recyclable rotary jet enlarged head anchor cable according to the present invention;

[0035] Figure 5 This is a schematic diagram of a construction method of a recyclable rotary grouting enlarged head anchor cable according to the present invention;

[0036] Figure 6 It is a schematic diagram of the enlarged head anchoring section of the construction method;

[0037] Figure 7 It is a schematic diagram of the conventional anchoring section of the construction method;

[0038] Figure 8It is a free section schematic diagram of the construction method;

[0039] Figure 9 It is a schematic diagram of the tensioning section of the construction method;

[0040] Figure 10 This is a schematic diagram of a positioning receiving block of a locking and recovery device for a recoverable jet-jet enlarged head anchor cable;

[0041] The markings of the components in the accompanying drawings are as follows: 1-pressure-bearing cover plate; 101-pressure-bearing plate; 102-screw hole; 103-through hole; 2-pressure-bearing anchor plate; 201-through hole; 202-conical seat sleeve; 3-bolt; 301-fixing screw; 302-nut; 40-locking structure; 401-guide anchor protection tube; 402-pinning steel wire; 403-connecting tube; 404-clip anchor plate; 41-releasing structure; 411-steel sleeve tube; 412-spring; 413-positioning receiving block; 4131-self-locking joint; 4132-guide Toward cylinder; 4133-connecting part; 414-conduit; 415-locking buckle; 416-guide connecting line; 5-rotating pressure bearing; 601-drill pipe; 602-jet drill bit; 6021-high-pressure nozzle; 701-enlarged head anchoring section; 702-conventional anchoring section; 703-free section; 704-tensioning section; 706-locking recovery device; 707-prestressed steel strand; 708-protective casing; 709-buried PVC pipe; 710-anchor pad; 711-sprayed anchor surface layer; 8-recoverable anchor cable. DETAILED DESCRIPTION

[0042] The purpose of the present invention is described in further detail below with reference to the accompanying drawings and specific examples. The examples cannot be described one by one here, but the implementation methods of the present invention are not limited to the following examples.

[0043] Anchor cables are widely used in foundation pit support projects. Recyclable anchor cables 8 in temporary foundation pits can recycle prestressed steel strands 707 from the soil for secondary reuse. The entire length of the recyclable anchor cable 8 is free and unbonded, and the prestressed steel strands 707 are protected by a protective sleeve 708, which is a PVC hose. Within the expanded anchor section 701 in the soil, the recyclable anchor cable 8 connects to the conical seat sleeve 202 of the pressure anchor plate 2. The pressure anchor plate 2 transfers pressure to the cement slurry in the expanded anchor section 701. This creates shear and frictional resistance between the cement slurry and the rock or soil, achieving tension anchoring. The anchoring force of the recyclable expanded anchor cable is primarily generated in the expanded anchor section 701.

[0044] like Figure 6As shown, a recyclable rotary jet enlarged head anchor cable includes a rotary jet drill bit 602, a locking and recovery device 706, a recyclable anchor cable 8, a drill rod 601, a protective sleeve 708 and a prestressed steel strand 707. The anchor drill rig is connected to the locking and recovery device 706 through the drill rod 601, the rotary jet drill bit 602 is installed in the locking and recovery device 706, the drill rod 601 and the rotary jet drill bit 602 can rotate relative to the locking and recovery device 706, and the recyclable anchor cable 8 is installed around the rotary jet drill bit 602, that is, one end of the recyclable anchor cable 8 is locked in the locking and recovery device 706, and the other end of the recyclable anchor cable 8 is connected to one end of the prestressed steel strand 707, the protective sleeve 708 is connected to the locking and recovery device, and the other end of the prestressed steel strand 707 passes through the protective sleeve 708 and protrudes out of the pipe.

[0045] The jet grouting drill bit 602 is used for high-pressure injection and drilling of cement slurry; the locking and recovery device 706 is used to lock and release the recoverable anchor cable 8; the drill rod 601 is used to drive and push and pull the jet grouting drill bit 602; the protective casing 708 is used to protect the prestressed steel strand 707; the prestressed steel strand 707 is used to tension the recoverable anchor cable 8.

[0046] like Figure 1-4As shown, the locking and recovery device includes a pressure-bearing cover plate 1, a pressure-bearing anchor plate 2, two bolts 3, four locking structures 40, four release structures 41, and a rotating pressure bearing 5. Each release structure 41 includes a steel sleeve tube 411, a spring 412, a positioning receiving block 413, a guide connecting wire 416, a guide tube 414, and a lock buckle 415. Each locking structure 40 includes a guide anchor protection tube 401, a pinning steel wire 402, a connecting tube 403, and an anchor clamp 404. The bolt 3 includes two nuts 302 and a fixing screw 301. The pressure anchor plate 2 has a through hole 201 at its center. Four conical seat sleeves 202 are provided around the through hole 201. Four recoverable anchor cables 8 are respectively installed in the four conical seat sleeves 202 via anchor clamps 404. The left end of the retrievable anchor cable 8 is connected to the right end of the positioning receiving block 413 via a guide connecting line 416. The two ends of the spring 412 are respectively connected to the clamping anchor plate 404 and the right end of the positioning receiving block 413. The connecting pipe 403 is connected to the conical seat sleeve 202 of the pressure anchor plate 2. The right end of the retrievable anchor cable 8 protrudes from the right end of the connecting pipe 403 and connects to the prestressed steel strand 707. The left end of the pinning wire 402 is clamped between the conical seat sleeve 202 and the clamping anchor plate 404. The right end of the pinning wire 402 passes through the connecting pipe 403, the guide anchor protection tube 401, and the protective sleeve 708, and the pinning wire 402 protrudes to the outside. The guide anchor tube 401 is connected to the narrow end of the conical seat sleeve 202. The retrievable anchor cable 8, connecting tube 403, and pinning steel wire 402 are all located in the inner cavity of the guide anchor tube 401. The four guide anchor tubes 401 and the drill rod 601 are all set in the protective sleeve 708, and the protective sleeve 708 is connected to the pressure anchor plate 2. The wide end of the conical seat sleeve 202 of the pressure anchor plate 2 is connected to the right end of the steel sleeve tube 411. A through hole 103 is provided in the center of the pressure plate 101 of the pressure cover plate 1. Four steel sleeve tubes 411 are connected around the through hole 103. Four locking buckles 415 are respectively set in the four steel sleeve tubes 411, and the four locking buckles 415 are also installed on the pressure plate 101. The right end of the lock 415 is connected to the guide tube 414, which is mounted on the inner wall of the steel sleeve tube 411. The positioning receiving block 413 can move left and right within the guide tube 414, and the left end of the positioning receiving block 413 can be inserted into the lock 415 to achieve automatic locking. The jet grouting drill bit 602 passes through the through hole 201 of the pressure anchor plate 2 and the through hole 103 of the pressure cover plate 1 in sequence. The jet grouting drill bit 602 is connected to the drill rod 601, and the connection between the jet grouting drill bit 602 and the drill rod 601 is mounted on the rotary pressure bearing 5. The jet grouting drill bit 602 is equipped with two high-pressure nozzles 6021: one high-pressure nozzle 6021 is located on the left side of the pressure cover plate 1, and the other high-pressure nozzle 6021 is located between the pressure cover plate 1 and the pressure anchor plate 2. The two high-pressure nozzles 6021 are arranged on the jet grouting drill bit 602 in opposite directions. The rotary pressure bearing 5 is installed at the right end of the pressure anchor plate 2 , and the jet grouting drill bit 602 and the drill rod 601 can both rotate relative to the rotary pressure bearing 5 .Two screw holes 102 are provided at symmetrical positions on the periphery of the through hole 201 of the pressure anchor plate 2, and two screw holes 102 are also provided at symmetrical positions on the periphery of the through hole 103 of the pressure cover plate 1. The two ends of each fixing screw 301 pass through a screw hole 102 of the pressure cover plate 1 and a screw hole 102 of the pressure anchor plate 2 respectively, and two nuts 302 are respectively installed at the two ends of the fixing screw 301.

[0047] The positioning receiving block 413 includes a self-locking joint 4131, a guide cylinder 4132 and a connecting part 4133 connected in sequence. The self-locking joint 4131 and the lock buckle 415 can cooperate with each other to achieve self-locking. The guide cylinder 4132 is movably installed on the inner wall of the catheter 414. The connecting part 4133 is connected to the guide connecting line 416, and the right end of the guide cylinder 4132 is connected to the spring 412.

[0048] The pressure cover plate 1 is used to support and fix the jet grouting drill bit 602 to improve the anchoring force; the pressure anchor plate 2 is used to lock the recyclable anchor cable 8; the bolt 3 is used to fix the pressure cover plate 1 and the pressure anchor plate 2; the locking structure 40 is used to lock the recyclable anchor cable 8; the release structure 41 is used to release the recyclable anchor cable 8; the rotating pressure bearing 5 prevents the drill rod 601 and the jet grouting drill bit 602 from driving the recyclable anchor cable 8 to cause it to twist during rotation; the steel sleeve tube 411 is used to protect the internal components; the spring 412 is used to connect the clamping anchor plate 404 and the positioning receiving block 413; the self-locking joint 4131 of the positioning receiving block 413 is used to lock with the lock buckle 415; the cooperation of the guide cylinder 4132 and the guide tube 414 realizes the guiding effect and drives the clamping anchor plate 404 to disengage from the cone The seat sleeve 202; the guide connecting line 416 is used to position the receiving block 413 to drive the recyclable anchor cable 8; the lock buckle 415 cooperates with the self-locking joint 4131 to achieve locking, so as to prevent the clamping anchor piece 404 from returning to the conical seat sleeve 202; the guide anchor protection tube 401 is used to protect the recyclable anchor cable 8; the pinning steel wire 402 is used to fill the gap between the clamping anchor piece 404 and the conical seat sleeve 202, and increase the locking force of the conical seat sleeve 202 on the recyclable anchor cable 8. After the pinning steel wire 402 is pulled out, the locking force of the conical seat sleeve 202 on the recyclable anchor cable 8 is reduced or disappears; the connecting pipe 403 is used to protect the shell recovery anchor cable and the pinning steel wire 402; the clamping anchor piece 404 is used to clamp the recyclable anchor cable 8; the bolt 3 is used to fix the pressure cover plate 1 and the pressure anchor plate 2.

[0049] Working principle of locking recovery device:

[0050] 1. Locking method of the recyclable anchor cable 8: When the recyclable anchor cable 8 passes through the conical seat sleeve 202 of the pressure anchor plate 2, the clamping anchor plate 404 is clamped on the recyclable anchor cable 8 and connected to the spring 412. The positioning receiving block 413 is connected to the end of the recyclable anchor cable 8 via the guide connecting line 416, that is, the positioning receiving block 413 is located at the right end of the steel sleeve tube 411. When the prestressed steel strand 707 is tensioned, the prestressed steel strand 707 pulls the recyclable anchor cable 8 outward from the conical seat sleeve 202 of the pressure anchor plate 2. The recyclable anchor cable 8 drives the clamping anchor plate 404 to lock and bite the conical seat sleeve 202. The recyclable anchor cable 8 drives the positioning receiving block 413 to press the clamping anchor plate 404 against the conical seat sleeve 202 via the spring 412, thereby locking the recyclable anchor cable 8.

[0051] 2. Recovery method of the recyclable anchor cable 8: After releasing the tension locking force of the prestressed steel strand 707, use a jack to first pull out the pinning steel wire 402 from the conical seat sleeve 202 of the pressure anchor plate 2 and recover it. At this time, there are more gaps in the conical seat sleeve 202, and the locking force of the clamping anchor piece 404 and the conical seat sleeve 202 on the recyclable anchor cable 8 is reduced or disappears. The recyclable anchor cable 8 is pushed into the conical seat sleeve 202, and the recyclable anchor cable 8 pushes the positioning receiving block 413 to move to the left. The positioning receiving block 413 is locked with the lock buckle 415. At the same time, the positioning receiving block 413 drives the clamping anchor piece 404 to disengage from the conical seat sleeve 202 through the spring 412. The recyclable anchor cable 8 is then pulled outward from the conical seat sleeve 202, and the clamping anchor piece 404 is fixed as a receiving block, so it can be detached from the recyclable anchor cable 8, and then the recyclable anchor cable 8 is pulled out from the conical seat sleeve 202 again, and finally the recyclable anchor cable 8 is pulled out from the guide anchor protection tube 401, completing the recovery of the recyclable anchor cable 8.

[0052] like Figure 5-9 As shown, a construction method of a recyclable rotary grouting enlarged head anchor cable comprises the following steps:

[0053] S1. According to the elevation and horizontal spacing required by the design, set the location of the drilling hole in the foundation pit, and trim the drilling rig working soil platform according to the location of the drilling hole.

[0054] S2. Select an anchor drilling rig according to actual requirements, install the anchor drilling rig on the drilling rig working soil platform in step S1, install a jet grouting drill bit 602 on the drill rod 601 of the anchor drilling rig, align the jet grouting drill bit 602 with the position of the drill hole, turn on the anchor drilling rig, and the anchor drilling rig drives the jet grouting drill bit 602 to rotate. The jet grouting drill bit 602 drills the soil, and the jet grouting drill bit 602 and the drill rod 601 bring the waste soil residue out of the hole. Drilling is stopped until the rotating drill bit reaches the junction of the conventional anchoring section 702 and the enlarged head anchoring section 701. The aperture and depth of the conventional anchoring section 702 meet the design requirements, and the construction of the conventional anchoring section 702 is completed.

[0055] S3. Turn on the high-pressure pump to provide cement slurry to the jet drill bit 602. The jet drill bit 602 rotates, and the cement slurry is jetted out from the jet drill bit 602 at high pressure. The cement slurry jets and cuts the soil to form a large-diameter cement-soil cylindrical pile body. Turn on the grouting mode of the jet drill bit 602 to grout the large-diameter cement-soil cylindrical pile body, completing the construction of the enlarged head anchoring section 701.

[0056] S301. Turn on the high-pressure pump, which delivers high-pressure cement slurry to the jet drill bit 602. Driven by the anchor drill rig, drilling continues. The jet drill bit 602 rotates at a constant speed and sinks. Cement slurry is jetted out of the jet drill bit 602 at high pressure. The cement slurry expands the borehole diameter. The high-pressure jetting of the cement slurry cuts, displaces, stirs, penetrates, and squeezes the soil to form a large-diameter cement-soil cylindrical pile. The cement slurry uses Portland cement with a strength of no less than 42.5. When the length of the large-diameter cement-soil cylindrical pile exceeds the designed length by at least 0.5m, the jet drill bit 602 stops rotating and the high-pressure jetting of cement slurry ceases.

[0057] S302, pull the drill rod 601 out of the drill hole. When the jet grouting drill bit 602 reaches the junction of the conventional anchor anchoring section and the enlarged head anchoring section 701, start the high-pressure pump. The jet grouting drill bit does not rotate. Cement slurry is sprayed out from the jet grouting drill bit 602 at high pressure. The jet grouting drill bit 602 moves from bottom to top in the enlarged head anchoring section 701 to start the construction of the enlarged head anchoring section 701.

[0058] S4. Pull out the drill rod 601 and the jet grouting drill bit 602 from the borehole. After the recyclable anchor cable 8 passes the on-site acceptance inspection, remove the jet grouting drill bit 602 from the drill rod 601, install the jet grouting drill bit 602 on the locking recovery device, lock the recyclable anchor cable 8 on the locking structure 40 of the locking recovery device 706, connect the locking recovery device 706 to the drill rod 601, and push the jet grouting drill bit 602 and the recyclable anchor cable 8 to the bottom of the enlarged head anchor section 701 through the drill rod 601. During the process, it is necessary to ensure that the recyclable anchor cable 8 is straight.

[0059] S5. Perform secondary high-pressure rotary grouting on the enlarged head anchoring section 701 to ensure the strength and density of the cement slurry of the anchor body. After the rotary grouting drill bit 602 is pushed to the enlarged head anchoring section 701 by the anchor drilling rig, the high-pressure pump is turned on. The high-pressure pump transports the cement slurry to the rotary grouting drill bit 602. The anchor drilling rig drives the rotary grouting drill bit 602 to rotate, and the cement slurry is jetted out from the rotary grouting drill bit 602 at high pressure. The cement slurry is jetted and cuts the soil, making the diameter of the enlarged head anchoring section 701 much larger than the original diameter. The cement slurry is also filled in the enlarged head anchoring section 701 after the diameter is expanded, so that the locking recovery device 706 and the cement slurry around it form a cement consolidation slurry, completing the secondary grouting of the enlarged head anchoring section 701. The secondary grouting is beneficial to improving the connection density, strength and stability between the locking recovery device 706 and the enlarged head anchoring section 701. By adjusting the speed of the drill rod 601 and the pressure of the high-pressure pump, a larger and controllable enlarged head anchoring section 701 can be formed. The friction formed between the enlarged head anchoring section 701 and the rock and soil and the end bearing force between the enlarged head anchoring section 701 and the locking recovery device are significantly improved, which can provide a large-tonnage pull-out resistance for the recoverable anchor cable 8.

[0060] S6. After completing the secondary fluid replenishment of the enlarged head anchoring section 701, the four prestressed steel strands 707 are tensioned in the tensioning section 704. The prestressed steel strands 707 drive the recyclable anchor cable 8 to be tensioned and locked. The prestressed steel strands 707 of the same recyclable anchor cable 8 are required to be tensioned synchronously to ensure that each prestressed steel strand 707 is tensioned evenly, avoiding localized excessive stress and mutual influence that may cause damage to the recyclable anchor cable 8. Therefore, after two tensioning operations, the recyclable anchor cable 8 is locked by the clamping anchor plate 404 and the conical seat sleeve 202. Step S6 includes the following steps:

[0061] S601, performing the first tensioning of each prestressed steel strand 707 according to 30% of the design tensioning force of the prestressed steel strand;

[0062] S602. Then, the entire prestressed steel strand 707 is tensioned for the second time according to the designed tensioning force of the recyclable anchor cable 8. The recyclable anchor cable 8 drives the positioning receiving block 413 to approach the conical seat sleeve 202 through the guide connecting line 416. The positioning receiving block 413 pushes the spring 412 to press the clamping anchor piece 404. The clamping anchor piece 404 is pressed into the conical seat sleeve 202. At the same time, the recyclable anchor cable 8 drives the clamping anchor piece 404 to press the conical seat sleeve 202 to lock it.

[0063] S7, the recyclable anchor cable 8 is released and recovered from the locking and recovery device. Step S7 includes the following steps:

[0064] S701. Use a jack to pull out and recover the pinning wire 402 from between the conical seat sleeve 202 and the clamping anchor piece 404. When the pinning wire 402 is pulled out, a larger space is left between the clamping anchor piece 404 and the conical seat sleeve 202, causing the locking force of the clamping anchor piece 404 on the recyclable anchor cable 8 to decrease or disappear. The recyclable anchor cable 8 is pushed by the spring 412.

[0065] S702, the recyclable anchor cable 8 can be easily rotated, and the recyclable anchor cable 8 is pushed into the conical seat sleeve 202. The recyclable anchor cable 8 pushes the positioning receiving block 413 to approach the lock buckle 415 through the spring 412. The positioning receiving block 413 is fixedly connected to the self-locking joint 4131 and the lock buckle 415. At the same time, the positioning receiving block 413 drives the clamping anchor piece 404 to disengage from the conical seat sleeve 202 through the spring 412. The recyclable anchor cable 8 is no longer locked by the clamping anchor piece 404 and the conical seat sleeve 202. The recyclable anchor cable 8 is pulled outward, and the clamping anchor piece 404 is detached from the recyclable anchor cable 8 under the traction of the positioning receiving block 413. The guide connecting line 416 between the positioning receiving block 413 and the recyclable anchor cable 8 is disconnected, and the recyclable anchor cable 8 is detached from the pressure anchor plate 2. The recyclable anchor cable 8 is easily pulled out from the guide anchor protective tube 401, thereby realizing the recovery of the recyclable anchor cable 8.

[0066] The above specific implementation manner is a preferred embodiment of the present invention and does not limit the present invention. Any other changes or other equivalent replacement methods that do not deviate from the technical solution of the present invention are included in the protection scope of the present invention.

Claims

1. A recyclable jet-jet enlarged head anchor cable, characterized in that: The cam is connected to the drill pipe by a locking mechanism, and the other end of the locking mechanism is connected to the drill pipe by a locking mechanism. The locking structure includes a guide anchor protective tube, a pinning steel wire, a connecting tube and an anchor clamping plate. The pressure anchor plate is provided with a plurality of conical seat sleeves, and the plurality of conical seat sleeves are distributed around the rotary jet drill bit. The recyclable anchor cable is installed on the conical seat sleeve through the anchor clamping plate. The connecting tube is communicated with the conical seat sleeve. The connecting tube is installed on the guide anchor protective tube, and the guide anchor protective tube is installed on the protective sleeve. The other end of the recyclable anchor cable passes through the connecting tube and is connected to one end of the prestressed steel strand. One end of the pinning steel wire is clamped between the conical seat sleeve and the anchor clamping plate. The other end of the pinning steel wire passes through the connecting tube, the guide anchor protective tube and the protective sleeve in sequence.

2. A recyclable jet-jet enlarged head anchor cable according to claim 1, characterized in that: The release structure includes a steel sleeve tube, a spring, a positioning receiving block, a catheter and a lock. The two ends of the steel sleeve tube are respectively connected to the pressure cover plate and the pressure anchor plate. The positioning receiving block is installed on the inner wall of the steel sleeve tube through the catheter. The catheter is installed on the pressure cover plate through the lock. One end of the positioning receiving block matches the lock. The other end of the positioning receiving block is connected to one end of the recyclable anchor cable through a guide connecting line. The other end of the positioning receiving block is connected to the locking structure through a spring.

3. A recyclable rotary jet enlarged head anchor cable according to claim 2, characterized in that: The positioning receiving block includes a self-locking joint, a guide cylinder and a connecting portion connected in sequence, the self-locking joint matches the lock buckle, the guide cylinder is movably installed on the catheter, the connecting portion is connected to the guide connecting line, and the guide cylinder is connected to the spring.

4. The recyclable rotary jet enlarged head anchor cable according to claim 1, characterized in that: The jet grouting drill bit is provided with two high-pressure nozzles, one of which is located on a side of the pressure-bearing cover plate away from the pressure-bearing anchor plate, and the other is located between the pressure-bearing cover plate and the pressure-bearing anchor plate.

5. The recyclable jet-jet enlarged head anchor cable according to claim 1, characterized in that: The bolt includes a nut and a fixing screw, one end of the fixing screw passes through the pressure-bearing cover plate and is connected to a nut, and the other end of the fixing screw passes through the pressure-bearing anchor plate and is connected to another nut.

6. A construction method for a recyclable jet-jet anchor cable with an enlarged head according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1. According to the design requirements of elevation and horizontal spacing, set the location of the drilling hole in the foundation pit, and trim the drilling rig working soil platform according to the location of the drilling hole; S2, installing an anchor drilling rig on the drilling rig working soil platform of step S1, installing a rotary jet drill bit on the drill rod of the anchor drilling rig, aligning the rotary jet drill bit with the drilling position and drilling until the rotary drill bit reaches the junction of the conventional anchoring section and the enlarged head anchoring section, then stopping the drilling, and completing the construction of the conventional anchoring section; S3. Turn on the high-pressure pump to supply cement slurry to the jet grouting drill bit. The jet grouting drill bit starts to rotate. The cement slurry jets and cuts the soil to form a large-diameter cement-soil cylindrical pile. Turn on the grouting mode of the jet grouting drill bit to grout the large-diameter cement-soil cylindrical pile, completing the construction of the enlarged head anchoring section. S4. Pull the drill rod and the jet grouting drill bit out of the borehole, then remove the jet grouting drill bit from the drill rod, install the jet grouting drill bit and the recyclable anchor cable on the locking and recovery device, and then install the locking and recovery device on the drill rod; S5. Use a jet grouting drill bit to push the expanded head anchoring section, start the high-pressure pump, and the high-pressure pump will deliver cement slurry to the jet grouting drill bit. The jet grouting drill bit starts to rotate, and the cement will be jetted and cut into the soil. The diameter of the expanded head anchoring section is increased, and the cement slurry is simultaneously filled in the expanded head anchoring section, completing the secondary grouting of the expanded head anchoring section. S6. The prestressed steel strand is tensioned in the tensioning section. The prestressed steel strand drives the recyclable anchor cable to be tensioned. The recyclable anchor cable is locked by the clamping anchor sheet and the conical seat sleeve. S7. The recyclable anchor cable is recovered from the locking recovery device.

7. The construction method according to claim 6, characterized in that: Step S6 includes the following steps: S601, performing the first tensioning of each prestressed steel strand according to 30% of the design tensioning force of the prestressed steel strand; S602. Then, the entire prestressed steel strand is tensioned for the second time according to the designed tensioning force of the recyclable anchor cable. The recyclable anchor cable drives the positioning receiving block to approach the conical seat sleeve through the guide connecting line. The positioning receiving block presses the clamping anchor piece through the spring. At the same time, the recyclable anchor cable drives the clamping anchor piece to press the conical seat sleeve to lock it.

8. The construction method according to claim 6, characterized in that: Step S7 includes the following steps: S701. Use a jack to pull the pinning steel wire out from between the conical seat sleeve and the clamping anchor piece, so that the locking force of the clamping anchor piece and the conical seat sleeve on the recyclable anchor cable is reduced or eliminated; S702. Rotate the anchor cable and push it into the conical seat sleeve. The anchor cable pushes the positioning receiving block toward the lock buckle through the spring. The positioning receiving block is automatically connected to the self-locking joint and the lock buckle. At the same time, the spring drives the anchor clamping piece to detach from the conical seat sleeve. The recyclable anchor cable is pulled outward from the conical seat sleeve. The recyclable anchor cable is sequentially detached from the anchor clamping piece, the conical seat sleeve and the anchor guide tube, completing the recovery of the recyclable anchor cable.

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