A recyclable anchor rod and construction method thereof

Abstract

The present invention discloses a recyclable anchor rod, which includes a cement soil pile body and an anchor cable; the anchor cable includes sub-anchor cables, each sub-anchor cable includes a glass fiber anchor bar, a threaded steel bar and a steel strand connected in sequence, one end of the glass fiber anchor bar is connected to one end of the threaded steel bar through a sleeve, and the other end of the threaded steel bar is connected to one end of the steel strand through a wire rod connector; the sleeve is filled with hot melt material, and the glass fiber anchor bar and the threaded steel bar are respectively bonded in the sleeve; a first electric heating plate is buried in the hot melt material to melt the hot melt material between the glass fiber anchor bar and the sleeve; an anchor plate is connected to the anchor cable, the anchor plate has a central hole and anchor cable holes arranged around the central hole, and the anchor plate is sleeved on the glass fiber anchor bar through the anchor cable holes; the anchor plate is made of non-metallic material. A construction method of a recyclable anchor rod is also provided. The present application can reduce the metal parts left in the ground and reduce the impact on subsequent construction.

Description

Technical Field

[0001] The invention relates to a recoverable anchor rod and a construction method thereof. Background Art

[0002] The supporting pile fulcrums of foundation pit support can be realized by internal support and anchor cables. The cost of internal support is high, which affects the construction of the main structure. Anchor cables have the advantages of low cost and fast construction, but they need to occupy a large amount of underground space. The anchoring depth range of many anchor cables exceeds the building red line, which brings the problem of violating land use planning.

[0003] To solve this problem, people have developed recyclable anchor cable technology. After the anchor cable completes its task, the anchor cable is recycled, which can not only avoid the problem of the anchor cable exceeding the building red line, but also reduce the construction cost. At present, a variety of recyclable anchor cable technologies have been developed. However, when recycling the anchor cable, there is a problem that some anchors are left underground and cannot be recycled. These anchors are generally made of metal materials and buried in the grouting body to maintain the stability of the anchor cable in the grouting body. These anchors are generally large anchor plates or rods, where the length of the anchor plate is between 400-600mm, and the length of the rod is generally 2.0-2.5m.

[0004] Since these metal anchors are large in size, they will have a certain impact on subsequent construction if they are left underground. When underground construction continues in this area, when construction machinery hits these metal anchors, it will cause certain damage to the construction machinery, especially to cutting parts such as cutters or drill bits, which will cause irreparable damage. Sometimes, in order to remove these metal anchors, manual excavation is required to remove these metal anchors first, which seriously affects the construction efficiency of the area. Summary of the invention

[0005] In order to solve the above problems, the present invention first proposes a recyclable anchor rod, which can reduce the metal parts left underground and reduce the impact on subsequent construction. The specific technical solution is as follows:

[0006] A recyclable anchor rod comprises a cement soil pile body and an anchor cable, wherein the cement soil pile body has an enlarged head, one end of the anchor cable is located inside the enlarged head, and the other end of the anchor cable extends along an axial direction to form an anchor head end, and the anchor head end protrudes from the cement soil pile body;

[0007] The anchor cable comprises at least one sub-anchor cable, each sub-anchor cable comprises a glass fiber anchor bar, a threaded steel bar and a steel strand connected in sequence along the axis direction, the opposite ends of the glass fiber anchor bar are respectively formed as an anchor end and a traction end, the traction end of the glass fiber anchor bar is connected to one end of the threaded steel bar via a sleeve, the other end of the threaded steel bar is connected to one end of the steel strand via a wire rod connector, and the other end of the steel strand is extended out of the cement soil pile body to form an anchor head sub-end; the anchor head sub-ends of all the sub-anchor cables of the same anchor cable are jointly formed as an anchor head end;

[0008] The traction end of the fiberglass anchor bar and one end of the threaded steel bar are both extended into the sleeve, and the sleeve is filled with a hot-melt material, which bonds the fiberglass anchor bar and the threaded steel bar in the sleeve respectively, so that the fiberglass anchor bar and the threaded steel bar are connected together through the sleeve; a first electric heating plate is embedded in the hot-melt material, and the first electric heating plate is located between the fiberglass anchor bar and the sleeve, and the first electric heating plate is used to melt the hot-melt material between the fiberglass anchor bar and the sleeve;

[0009] At least one anchor plate is connected to the anchor cable, and the side surface of the anchor plate in the thickness direction is called the anchor surface. The anchor plate has a central hole and anchor cable holes arranged around the central hole. The central hole and the anchor cable holes extend along the thickness direction of the anchor plate and penetrate both sides of the thickness direction of the anchor plate. The anchor plate is sleeved on the glass fiber anchor bar through the anchor cable hole, and the anchor plate is connected to the glass fiber anchor bar. The anchor surface of the anchor plate is perpendicular to the axis direction. The anchor plate is made of non-metallic material. The anchor plate is preferably made of glass fiber reinforced plastic material.

[0010] The casing is preferably a steel casing, and the length of the casing is 0.5-0.8 meters. Fiberglass anchor bars are also called fiberglass bars or fiberglass anchor bars. The wire rod connector is used to connect threaded steel and steel strands together. It is relatively mature at present and can be directly purchased from the market.

[0011] One end of the first electric heating plate at least reaches the end face of one end of the glass fiber anchor bar in the sleeve, and the other end of the first electric heating plate at least reaches the end face of the sleeve away from the anchor head end. Preferably, the first electric heating plate starts from the end face of the sleeve away from the anchor head end and ends at the end face of the threaded steel bar in the sleeve, so that the first electric heating plate can fully heat the hot melt material surrounding the glass fiber anchor bar to melt it.

[0012] In the present application, the anchor cable is connected by glass fiber anchor bars, threaded steel bars and steel strands, wherein the steel strands play the role of generating prestress, and the threaded steel bars are used to connect the glass fiber anchor bars and the steel strands together. Although the glass fiber anchor bars have high tensile strength, it is not easy to connect them to the steel strands using clamping fasteners. In the present application, the glass fiber anchor bars are connected to the steel strands by using sleeves and threaded steel transitions. When recycling, the hot melt material is melted by the first electric heating plate to separate the steel sleeve from the glass anchor bars, and the steel strands are recycled, while the glass fiber anchor bars are left underground and are not recycled. Since the glass fiber anchor bars are brittle materials, they are very easy to break after being hit by external forces, so they will not cause damage to the machinery that continues to work in the area, and the glass fiber anchor bars will not cause environmental pollution in the area. In the present application, the glass fiber anchor bars are used to replace the metal anchors in the prior art, which can effectively avoid damage to the equipment that is subsequently constructed in the area.

[0013] The anchor plate is used to increase the stability of the anchor cable in the cement soil pile. In the present application, the anchor plate is made of non-metallic materials such as fiberglass, which will not be recycled and will remain underground. Since the anchor plate is made of non-metallic materials, preferably fiberglass, when construction continues in the area, the anchor plate will not cause damage to the construction machinery. Moreover, the anchor plate is easily broken by the construction equipment and will not affect the construction progress.

[0014] Furthermore, a second electric heating plate is embedded in the hot-melt material, and the second electric heating plate is located between the threaded steel and the casing; the second electric heating plate is used to melt the hot-melt material between the threaded steel and the casing; when the second electric heating plate is energized, the hot-melt material between the threaded steel and the casing can be heated and melted, and under the action of external force, the steel strand drives the threaded steel to come out of the casing.

[0015] One end of the second electric heating plate at least reaches the end face of the threaded steel bar in the sleeve, and the other end of the second electric heating plate at least reaches the end face of the sleeve facing the anchor head end. Preferably, the second electric heating plate starts from the end face of the glass fiber anchor bar in the sleeve and ends at the end face of the sleeve facing the anchor head end, so that the second electric heating plate can fully heat the hot melt material surrounding the threaded steel bar to melt it.

[0016] When the anchor cable is being recovered, if the casing cannot be separated from the cement soil pile body due to the excessive wrapping force of the cement soil pile body on the casing, and the anchor cable cannot be recovered, the second electric heating plate is energized to heat the hot-melt material between the casing and the threaded steel bar, so that the hot-melt material between the threaded steel bar and the casing is heated and melted, and the threaded steel bar is separated from the casing under the drive of the steel strand, thereby completing the recovery of the steel strand.

[0017] Furthermore, at least one of the first electric heating plate and the second electric heating plate is attached to the inner wall of the sleeve, and the sleeve is a metal sleeve.

[0018] When the first electric heating plate or the second electric heating plate is energized, the generated heat energy is transferred through the sleeve, thereby heating the hot-melt material between the sleeve and the fiberglass anchor bar or the sleeve and the threaded steel bar, preventing the local hot-melt material from failing to melt due to insufficient heat.

[0019] Specifically, the anchor cable includes at least three sub-anchor cables, and at least two anchor plates are installed on the anchor cable; corresponding to each sub-anchor cable, an anchor cable hole is arranged on each anchor plate, and the anchor cable holes are evenly arranged around the central hole, and the sub-anchor cables are inserted into the corresponding anchor cable holes; the anchor plates are arranged at intervals along the axial direction.

[0020] Under the connection of the anchor plate, the sub-anchor cables of each anchor cable and the anchor plate together form a cage-like structure, which is similar to the steel cage of the steel structure, thereby improving the connection strength between the anchor rod and the cement soil pile body, so that the glass fiber anchor bar can be firmly maintained in the cement soil pile body, and the pull-out resistance of the anchor rod is guaranteed.

[0021] Since it is difficult to ensure that the anchoring surface of the anchoring plate is perpendicular to the axis direction when the anchoring plate is placed in the cement soil pile body, it is necessary to perform secondary positioning under the pulling of each sub-anchor cable to ensure that the anchoring surface of the anchoring plate can be perpendicular to the axis direction. When each anchor cable is composed of only one sub-anchor cable or two sub-anchor cables, it is impossible to ensure that the anchoring surface of the anchoring plate is perpendicular to the axis direction during the actual construction. When at least three sub-anchor cables are set, it is only necessary to make the anchoring surface of the anchoring plate perpendicular to the extension direction of the anchor cable when making the anchor cable. After the anchoring plate is placed in the cement soil pile body, even if the anchoring surface of the anchoring plate cannot be perpendicular to the axis direction when the anchoring plate is placed in the cement soil pile body, it is only necessary to pull each sub-anchor cable along the axis direction to make the anchoring surface of the anchoring plate perpendicular to the axis direction.

[0022] Furthermore, at least one anchor plate is provided with a lock buckle, which is fixedly sleeved on the glass fiber anchor bar and located on the side of the corresponding anchor plate away from the anchor head end, and the lock buckle can be pressed against the anchor plate; the lock buckle is made of non-metallic material. Preferably, the anchor plate and the corresponding lock buckle are bonded together by an adhesive.

[0023] When the anchor cable is tensioned, the fiberglass anchor bar is stably connected to the anchor plate under the restriction of the lock buckle, which prevents the fiberglass anchor bar from moving significantly in the cement soil pile during tensioning, further ensuring the stability of the fiberglass anchor bar in the cement soil pile. When the anchor plate is simply bonded to the fiberglass anchor bar with an adhesive, the contact area between the fiberglass anchor bar and the anchor plate is too small, and the connection strength between the fiberglass anchor bar and the anchor plate is insufficient. Under the pull of external force, the fiberglass anchor bar is easily separated from the anchor plate, causing the failure of the anchor plate.

[0024] Secondly, the present application also provides a construction method of a recyclable anchor rod, which uses the above-mentioned recyclable anchor rod for construction, and the steps include:

[0025] (1) Making sub-anchor cables, and fixing anchor plates on the anchoring ends of the sub-anchor cables to form anchor cables;

[0026] (2) Use a jet grouting machine to construct a cement soil pile body with an enlarged head;

[0027] (3) Use the grouting pipe of the rotary grouting machine to insert the anchor cable into the enlarged head of the cement soil pile body and make the anchor plate reach the set position;

[0028] (4) Retract the grouting pipe of the rotary pile spraying machine and carry out additional grouting to fill the cavity formed when the anchor cable is inserted;

[0029] (5) When the cement soil pile reaches the age, the anchor cable is tensioned and locked;

[0030] (6) Carry out earth excavation and underground structure construction. After the underground structure construction is completed, the anchor cable is recovered. When recovering the anchor cable, firstly, the first electric heating plate is energized to heat the hot-melt material to soften the hot-melt material, and the anchor cable is pulled to recover the anchor cable.

[0031] In this construction method, the cement soil pile body is first constructed. Before the cement soil solidifies, the end of the anchor plate carrying the anchor cable is inserted into the cement soil pile body by using the grouting pipe of the rotary grouting pile machine. When the anchor cable is inserted into the cement soil pile body, the structure in the cement soil pile body will be partially damaged. During the withdrawal of the grouting pipe, supplementary grouting is performed in the cement soil pile body to strengthen the central area of ​​the cement soil pile body. The area where the cement slurry diffuses during the supplementary grouting is called the pile core, and all the anchor plates are located in the pile core to ensure the strength of the cement soil pile body and the stability of the anchor plate in the cement soil pile body. When supplementary grouting is performed in the cement soil pile body, the cement soil slurry can not only grout the cavities caused by inserting the anchor plate, but also the slurry can enter the holes and gaps caused by the solidification of the cement soil pile body, which has the effect of reinforcing the cement soil pile body and improving the strength of the cement soil pile body. The pile core formed during the supplementary grouting wraps the anchor plate, so that the anchor plate and the cement soil pile body form a whole.

[0032] At present, when using a rotary grouting pile machine to make an anchor rod, the construction of the pile hole is first completed, and then the anchor cable is inserted into the pile hole, and then grouting is performed in the pile hole to form a cement soil pile body, and one end of the anchor cable is fixed in the cement soil pile body at the same time. Although this construction method is relatively mature, since grouting is performed after the anchor cable is inserted into the pile hole, the anchor cable also deviates from the set position, so that the anchor cable is located on one side of the cement soil pile body, and a special support structure needs to be set to ensure that the anchor cable is located at the set position in the pile hole. In addition, during the solidification process of the cement soil, the cement soil will produce a certain shrinkage, cracks will be generated in the cement soil pile body, and the strength of the pile body will be reduced. In this application, supplementary grouting is performed in the cement soil pile body, and the cracks generated by the cement soil pile body during the solidification process can be filled to ensure the strength of the cement soil pile body.

[0033] Furthermore, a second electric heating plate is buried in the hot-melt material, and the second electric heating plate is located between the threaded steel and the casing; when recovering the anchor cable, the first electric heating plate is first energized to melt the hot-melt material between the fiberglass anchor and the casing, and then the steel strand is pulled to make the steel strand drive the threaded steel and the casing to separate from the cement soil pile body for recovery; when the steel strand cannot be pulled out of the cement soil pile body under the set traction force, the second electric heating plate is energized to melt the hot-melt material between the threaded steel and the casing, and the steel strand is pulled again to make the steel strand drive the threaded steel to separate from the cement soil pile body for recovery.

[0034] When the anchor cable is being recovered, if the casing cannot be separated from the cement soil pile body due to the excessive wrapping force of the cement soil pile body on the casing, and the anchor cable cannot be recovered, the second electric heating plate is energized to heat the hot-melt material between the casing and the threaded steel bar, so that the hot-melt material between the threaded steel bar and the casing is heated and melted, and the threaded steel bar is separated from the casing under the drive of the steel strand, thereby completing the recovery of the steel strand.

[0035] Specifically, when constructing the cement soil pile body, the first lifting rod speed is 10-20 cm / min, the first grouting pressure is 25-30 MPa, the rotation speed of the nozzle is 10-20 rpm, the cement slurry is pure cement slurry with a water-cement ratio of 0.5-0.8, and the cement addition amount is 25-35%; the cement addition amount refers to the amount of cement contained in the formed cement soil pile body based on the soil;

[0036] When performing supplementary grouting, the second rod lifting speed is 18-30cm / min, and the second grouting pressure is 20-25MPa. The first rod lifting speed and the second rod lifting speed both refer to the lifting speed of the shotcrete pipe during construction. The second rod lifting speed is greater than the first rod lifting speed, and the second grouting pressure is less than the first grouting pressure.

[0037] In this application, during the supplementary grouting, a relatively high pressure and a relatively high rod lifting speed are used. During the supplementary grouting, the cement soil pile body is surrounded, and the injected cement slurry will be limited to a small range. Under the above-mentioned second rod lifting speed and second grouting pressure, the strength of the cement soil pile body can be guaranteed. During the construction of the cement soil pile body, since the soil body needs to be cut at the same time, the first rod lifting speed and the first grouting pressure are higher than the second rod lifting speed and the second grouting pressure.

[0038] Furthermore, in order to avoid forming a relatively independent cement soil structure during supplementary grouting, the diffusion radius of the cement slurry is 30-50% of the radius of the expansion head during supplementary grouting. After the supplementary grouting is completed, a relatively independent structure will not be formed in the cement soil pile body, and the cement soil pile body can be kept as an integral structure.

[0039] Furthermore, the anchor plate is located within the diffusion radius of the cement slurry during supplementary grouting.

[0040] That is, all anchor plates are located within the diffusion radius of cement slurry during supplementary grouting, and are evenly spaced. The anchor cable in this application is inserted into the enlarged head at one end of the anchor cable including the anchor plate after the construction of the cement soil pile body is completed and before the cement soil solidifies. When the anchor cable is inserted into the enlarged head, the structure in the cement soil pile body will be partially damaged. After the anchor plate and one end of the anchor cable are inserted into the cement soil pile body by using the grouting pipe of the pile mixing machine, the grouting is performed in the cement soil pile body by using the grouting pipe to strengthen the central area of ​​the cement soil pile body, and all anchor plates are located within the diffusion radius of the cement slurry to ensure the strength of the cement soil pile body and the stability of the anchor plate in the cement soil pile body. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a simplified diagram of underground structure construction using an embodiment of the present invention.

[0042] Figure 2 yes Figure 1 Enlarged view of part D.

[0043] Figure 3 yes Figure 2 Center AA view.

[0044] Figure 4 yes Figure 2 The enlarged view of part E in the middle is for clear display. Figure 4 Only the relevant structures of the anchor cables are shown.

[0045] Figure 5 yes Figure 4 View from the center BB direction.

[0046] Figure 6 yes Figure 4 View from the CC direction. DETAILED DESCRIPTION

[0047] See also Figure 1 , Figure 1 A partial view of an underground structure during construction using an embodiment of the present application.

[0048] Figure 1 In the figure, the direction of the arrow M marked at the appropriate position indicates the direction of the axis.

[0049] The retrievable anchor rod 200 is located in the soil around the foundation pit 121 . The retrievable anchor rod 200 includes a cement soil pile body 30 and an anchor cable 10 . The cement soil pile body 30 extends along the axis direction and has an enlarged head 32 .

[0050] One end of the anchor cable 10 is located inside the enlarged head, and the other end of the anchor cable 10 extends along the axis direction to form an anchor head end 15, and the anchor head end 15 extends out of the cement soil pile body 30. In this embodiment, the anchor head end 15 is fixed to the surrounding purlin 111 by a lock 122 after tensioning, and the surrounding purlin 111 is erected on the supporting pile 110 of the foundation pit 121. The foundation pit 121 is used to construct an underground structure 125. Figure 1 , reference numeral 100 denotes the ground.

[0051] The enlarged head 32 is located at an end of the cement soil pile body 30 away from the anchor head end 15 .

[0052] Please see below Figure 2-Figure 6 In this embodiment, one anchor cable 10 includes six sub-anchor cables 105, each of which includes a glass fiber anchor bar 13, a threaded steel bar 12 and a steel strand 11 connected in sequence along the axis direction, wherein the threaded steel bar 12 is a finely rolled threaded steel bar. It can be understood that in other embodiments, each anchor cable can be provided with only one sub-anchor cable, or two sub-anchor cables, or more sub-anchor cables, such as three, four, or ten sub-anchor cables, but it is recommended to provide at least three sub-anchor cables to facilitate the installation of the anchor plate described below.

[0053] The opposite ends of the glass fiber anchor bar 13 are respectively formed as an anchoring end 131 and a traction end 132. The traction end 132 of the glass fiber anchor bar 13 is connected to one end of the threaded steel bar 12 via a sleeve 17, and the other end of the threaded steel bar 12 is connected to one end of the steel strand 11 via a wire rod connector 16. The other end of the steel strand 11 extends out of the cement soil pile body to form an anchor head end, and the anchor head ends of all the anchor cables of the same anchor cable are collectively formed as the anchor head end.

[0054] The wire rod connector 16 is used to connect the threaded steel bar 12 and the steel strand 11 together. It is relatively mature at present and can be directly purchased from the market. In this embodiment, the wire rod connector produced by Henan Lei Te Prestressed Co., Ltd. is specifically used.

[0055] Inside the casing, along the length direction of the casing, there is a gap of 2-5mm between the fiberglass anchor bar and the threaded steel bar.

[0056] The traction end of the fiberglass anchor bar 11 and one end of the threaded steel bar 12 are both extended into the connected sleeve 17, and the sleeve is filled with hot melt material 14, which bonds the fiberglass anchor bar and the threaded steel bar in the sleeve respectively, so that the fiberglass anchor bar and the threaded steel bar are connected together through the sleeve.

[0057] The sleeve 17 is made of a 0.6-meter-long carbon steel pipe, and an internal thread is provided in the sleeve. The sleeve is filled with a hot-melt material 14, and in this embodiment, a hot-melt epoxy resin is specifically used as the hot-melt material. The hot-melt material bonds the glass fiber anchor bar 13 and the threaded steel bar 12 in the sleeve 17, respectively, so that the glass fiber anchor bar and the threaded steel bar are connected together. It can be understood that in other embodiments, the sleeve can also be made of other high-strength alloy steel pipes or non-ferrous metal pipes.

[0058] The first electric heating sheet 18 and the second electric heating sheet 19 are embedded in the hot melt material. In this embodiment, the first electric heating sheet 18 and the second electric heating sheet 19 are both sheet-shaped electric heating sheets. The first electric heating sheet 18 and the second electric heating sheet 19 are both attached to the inner wall of the sleeve. It can be understood that in other embodiments, only the first electric heating sheet 18 or the second electric heating sheet 19 can be attached to the inner wall of the sleeve. Of course, attaching both to the inner wall of the sleeve is a better choice.

[0059] When the first electric heating plate 18 or the second electric heating plate 19 is attached to the inner wall of the sleeve, when the first electric heating plate and the second electric heating plate are energized, the heat energy generated is transferred through the sleeve, thereby heating all the hot-melt materials in the sleeve, preventing local hot-melt materials from failing to melt due to insufficient heat.

[0060] In this embodiment, the first electric heating plate 18 is located between the glass fiber anchor bar and the sleeve. The first electric heating plate starts from the end face of the sleeve away from the anchor head end and ends at the end face of the threaded steel bar located in the sleeve.

[0061] The second electric heating plate 19 is located between the threaded steel bar and the sleeve. The second electric heating plate starts from the end face of the glass fiber anchor bar located in the sleeve and ends at the end face of the sleeve facing the anchor head.

[0062] The surface of the rebar and the inner surface of the casing need to be cleaned so that the hot melt material can be tightly bonded to the surface of the rebar and the inner surface of the casing. At the same time, the outer surface of the casing and the fiberglass anchor bar should also be cleaned to ensure good bonding with the surrounding cement soil.

[0063] The sheath of the steel strand 11 connected to the end of the utility pole connector 16 is stripped, and the sheath-stripped portion is cleaned so that the utility pole connector can be stably connected to the steel strand.

[0064] In this embodiment, three anchor plates 41 are provided corresponding to the anchor cable. The anchor plates are made of non-metallic materials. In this embodiment, the anchor plates are in a circular shape and are formed by pressing a wound fiber epoxy composite material. The side surface in the thickness direction of the anchor plate is called the anchor surface. Each anchor plate 41 has a center hole 411 and six anchor holes 412 evenly arranged around the center hole 411. The center hole and the anchor holes extend along the thickness direction of the anchor plate and pass through both sides of the thickness direction of the anchor plate. Each anchor hole 412 corresponds to a fiberglass anchor bar 13, and the anchor plate 41 is mounted on the fiberglass anchor bar through the anchor hole 412. The anchor plates are spaced apart along the axis direction. To show clearly, Figure 3 The fiberglass anchor bars in the two anchor cable holes were removed.

[0065] A lock buckle 42 is sleeved on the glass fiber anchor bar 13. On each glass fiber anchor bar 13, a lock buckle 42 is provided corresponding to each anchor plate 41. The lock buckle is made of non-metallic material, and in this embodiment, it is made of glass fiber reinforced plastic material. The lock buckle is bonded to the glass fiber anchor bar 13 with epoxy resin. Each lock buckle is located on the side of the corresponding anchor plate away from the anchor head end. The lock buckle is bonded to the glass fiber anchor bar 13 with epoxy resin. When the anchor cable is tensioned, the lock buckle abuts against the side of the anchor plate away from the anchor head end, so that the glass fiber anchor bar 13 is kept on the anchor plate. The stability of the anchor plate in the cement soil pile body is used to prevent the anchor cable from detaching from the cement soil pile body.

[0066] When installing the anchor plate, the anchoring surface of the anchor plate is made perpendicular to the extension direction of the glass fiber anchor bar 13 as much as possible to increase the stability of the anchor plate in the cement soil pile body.

[0067] In order to facilitate the insertion of the anchor plate into the cement soil pile, in this embodiment, the lock buckle is bonded to the corresponding anchor plate using epoxy resin. When the anchor plate is inserted into the cement soil pile, the lock buckle is kept together with the corresponding flange, reducing the movement of the glass fiber anchor bar when the anchor cable is tensioned. In order to avoid the separation of the anchor plate and the corresponding lock buckle, it can be understood that in other embodiments, the anchor plate and the corresponding lock buckle can be bonded together using epoxy resin or other adhesives. In this way, when the anchor cable is inserted into the cement soil pile, due to the cement soil bonding between the anchor plate and the lock buckle, when the anchor cable is tensioned, the anchor surface of the anchor plate is not perpendicular to the extension direction of the anchor cable, which affects the force of the anchor plate in the cement soil pile.

[0068] The following describes the use of the first electric heating plate 18 and the second electric heating plate 19. When the first electric heating plate 18 is energized, the hot melt material between the sleeve and the fiberglass anchor bar is heated and melted, and the anchor head end is pulled by a jack or a winch, so that the steel strand drives the threaded steel and the sleeve to separate from the fiberglass anchor bar for recovery. When the anchor cable is recovered, if the wrapping force of the cement soil pile body on the sleeve is too large, resulting in the sleeve being unable to separate from the cement soil pile body and the anchor cable cannot be recovered, the second electric heating plate is energized to heat the hot melt material between the sleeve and the threaded steel, so that the hot melt material between the threaded steel and the sleeve is heated and melted, and the threaded steel is separated from the sleeve under the drive of the steel strand, completing the recovery of the steel strand.

[0069] Regardless of the recycling method, the fiberglass anchor bars and anchor plates are kept underground. Since the fiberglass anchor bars and anchor plates are made of non-metallic materials, they will not affect the subsequent construction of the area. The rebar is recycled together with the steel strand and will not be kept underground, avoiding any impact on the subsequent construction.

[0070] During part of the construction process, the casing will be retained underground. Since the length of the casing is set within 0.8 meters, it will not affect the subsequent construction in the area, thus avoiding inconvenience caused to subsequent construction in the anchor construction area during anchor construction.

[0071] The following is an explanation of the construction method of the recyclable anchor rod 200, which specifically includes the following steps:

[0072] (1) Use the wire rod connector 16 to connect one end of the steel strand 11 with one end of the rebar 12, then insert the other end of the rebar 12 and one end of the fiberglass anchor 13 into the sleeve, and put the first electric heating plate 18 and the second electric heating plate 19 into the sleeve, inject the hot melt material in a molten state into the sleeve, and fill the sleeve with the hot melt material to completely wrap the fiberglass anchor 13 and the part of the rebar 12 located in the sleeve, cool the hot melt material until it reaches room temperature, solidify the hot melt material, and connect the fiberglass anchor 13 and the rebar 12. The end of the steel strand 11 away from the wire rod connector 16 becomes the anchor head end 15.

[0073] The anchor plate 41 and the lock buckle 42 are sleeved on the fiberglass anchor bar 13, and then bonded to the anchor end 131 with epoxy resin, and the anchor plate 41 and the corresponding lock buckle 42 are abutted against each other, and the lock buckle 42 is located on the side of the corresponding anchor plate 41 away from the sleeve.

[0074] One ends of the six anchor cables are connected together via an anchor plate, and the other ends are tied together to form an anchor cable 10. All anchor head sub-ends of the same anchor cable are jointly formed into an anchor head end.

[0075] (2) Construct support piles 110, excavate foundation pit 121, and install surrounding purlins 111. When the construction elevation of the recyclable anchor rod 200 is reached, the excavation of the foundation pit is suspended, and a rotary jet pile machine is used to form a cement soil pile body 30, and an enlarged head 32 is formed at the end of the cement soil pile body 30 away from the foundation pit.

[0076] (3) Insert the grouting pipe of the jet grouting machine into the center hole of the anchor plate, and then use the grouting pipe to insert the end of the anchor cable 10 with the anchor plate into the enlarged head 32 of the cement soil pile body 30, and make the anchor plate reach the set position.

[0077] (4) Retract the grouting pipe of the rotary pile spraying machine and carry out additional grouting at the same time to fill the cavity formed when the anchor cable is inserted.

[0078] (5) When the cement soil pile reaches the age, the anchor cable is tensioned and locked to the surrounding purlin 111.

[0079] (6) Carry out earth excavation and underground structure construction. After the underground structure construction is completed, the anchor cable is recovered.

[0080] When recovering the anchor cable, firstly, the first electric heating plate is energized to heat the hot-melt material between the casing and the glass fiber anchor bar to melt the hot-melt material, and the anchor head end is pulled by a winch, that is, the anchor cable is pulled. Driven by the steel strand, the threaded steel drives the casing to be pulled out of the cement soil pile body together, and the steel strand is recovered.

[0081] When the anchor cable is being pulled, if the steel strand cannot be pulled out after the set traction force is reached, the second electric heating plate is energized to melt the hot-melt material between the threaded steel and the casing, and the steel strand is pulled again to allow the steel strand to drive the threaded steel out of the cement soil pile body for recovery.

[0082] In this embodiment, when constructing the cement soil pile, the first lifting rod speed is 15 cm / min, the first grouting pressure is 30 MPa, the rotation speed of the nozzle is 17 rpm, the cement slurry is pure cement slurry with a water-cement ratio of 0.5, and the cement addition amount is 30%.

[0083] When performing supplementary grouting, the second rod lifting speed is 22cm / min and the second grouting pressure is 22MPa.

[0084] It can be understood that in other embodiments, when constructing a cement-soil pile, the first lifting rod speed can also be 10 cm / min, 12 cm / min, 18 cm / min or 20 cm / min, the first grouting pressure can also be 25 MPa, 26 MPa or 28 MPa, the rotation speed of the nozzle is 10 rpm, 15 rpm or 20 rpm, the cement slurry is pure cement slurry with a water-cement ratio of 0.6, 0.7 or 0.8, and the cement addition amount is 25% or 35%.

[0085] When performing supplementary grouting, the second rod lifting speed can also be 18 cm / min, 20 cm / min, 25 cm / min or 30 cm / min, and the second grouting pressure can also be 20 MPa, 24 MPa or 25 MPa.

[0086] When performing supplementary grouting, the second rod lifting speed should be faster than the first rod lifting speed, and the second grouting pressure should be lower than the first grouting pressure.

[0087] In this embodiment, when supplementary grouting is performed, the diffusion radius of the cement slurry is 35% of the radius of the enlarged head. It is understood that in other embodiments, when supplementary grouting is performed, the diffusion radius of the cement slurry is 30%, 40%, 45% or 50% of the radius of the enlarged head.

Claims

1. A recyclable anchor, characterized in that: It comprises a cement soil pile body and an anchor cable, wherein the cement soil pile body has an enlarged head, one end of the anchor cable is located inside the enlarged head, and the other end of the anchor cable extends along an axial direction to form an anchor head end, and the anchor head end protrudes out of the cement soil pile body; The anchor cable comprises at least three sub-anchor cables, each of which comprises a glass fiber anchor bar, a threaded steel bar and a steel strand connected in sequence along the axis direction, the opposite ends of the glass fiber anchor bar are respectively formed as an anchor end and a traction end, the traction end of the glass fiber anchor bar is connected to one end of the threaded steel bar via a sleeve, the other end of the threaded steel bar is connected to one end of the steel strand via a wire rod connector, and the other end of the steel strand is extended out of the cement soil pile body to form an anchor head sub-end; the anchor head sub-ends of all the sub-anchor cables of the same anchor cable are jointly formed as an anchor head end; The traction end of the fiberglass anchor bar and one end of the threaded steel bar are both extended into the sleeve, and the sleeve is filled with hot-melt material, which bonds the fiberglass anchor bar and the threaded steel bar in the sleeve respectively, so that the fiberglass anchor bar and the threaded steel bar are connected together through the sleeve; a first electric heating plate is embedded in the hot-melt material, and the first electric heating plate is located between the fiberglass anchor bar and the sleeve, and the first electric heating plate is used to melt the hot-melt material between the fiberglass anchor bar and the sleeve; a second electric heating plate is embedded in the hot-melt material, and the second electric heating plate is located between the threaded steel bar and the sleeve; the second electric heating plate is used to melt the hot-melt material between the threaded steel bar and the sleeve; when the second electric heating plate is energized, the hot-melt material between the threaded steel bar and the sleeve can be heated and melted, and under the action of external force, the steel strand drives the threaded steel bar to come out of the sleeve; At least two anchor plates are installed on the anchor cable, and the side surface of the anchor plate in the thickness direction is called the anchor surface. The anchor plate has a central hole and anchor cable holes arranged around the central hole. The central hole and the anchor cable holes extend along the thickness direction of the anchor plate and penetrate through both sides of the thickness direction of the anchor plate. The anchor plate is sleeved on the glass fiber anchor bar through the anchor cable hole, and the anchor plate is connected to the glass fiber anchor bar. The anchor surface of the anchor plate is perpendicular to the axial direction. The anchor plate is made of non-metallic material. Corresponding to each sub-anchor cable, an anchor cable hole is provided on each anchor plate, and each anchor cable hole is evenly arranged around the central hole, and the sub-anchor cables are inserted into the corresponding anchor cable holes; each anchor plate is arranged at intervals along the axis direction; A lock buckle is provided corresponding to at least one anchor plate. The lock buckle is fixedly sleeved on the glass fiber anchor bar and is located on the side of the corresponding anchor plate away from the anchor head end. The lock buckle can be pressed against the anchor plate. The lock buckle is made of non-metallic material.

2. The retrievable anchor rod according to claim 1, characterized in that: At least one of the first electric heating plate and the second electric heating plate is attached to the inner wall of the sleeve, and the sleeve is a metal sleeve.

3. A method for constructing a recyclable anchor rod, which is used for the construction of the recyclable anchor rod according to claim 1, characterized in that the steps include: (1) Making sub-anchor cables, and fixing anchor plates on the anchoring ends of the sub-anchor cables to form anchor cables; (2) Use a jet grouting machine to construct a cement soil pile body with an enlarged head; (3) Use the grouting pipe of the rotary grouting machine to insert the anchor cable into the enlarged head of the cement soil pile body and make the anchor plate reach the set position; (4) Retract the grouting pipe of the rotary pile spraying machine and carry out additional grouting to fill the cavity formed when the anchor cable is inserted; (5) When the cement soil pile reaches the age, the anchor cable is tensioned and locked; (6) Carry out earth excavation and underground structure construction. After the underground structure construction is completed, the anchor cable is recovered. When recovering the anchor cable, firstly, the first electric heating plate is energized to heat the hot-melt material to soften the hot-melt material, and the anchor cable is pulled to recover the anchor cable.

4. The construction method according to claim 3, characterized in that: When recovering the anchor cable, firstly, the first electric heating plate is energized to melt the hot-melt material between the glass fiber anchor bar and the casing, and then the steel strand is pulled to make the steel strand drive the threaded steel and the casing to separate from the cement soil pile body for recovery; When the steel strand cannot be pulled out of the cement soil pile under the set traction force, the second electric heating plate is energized to melt the hot melt material between the threaded steel and the casing, and the steel strand is pulled again to drive the threaded steel out of the cement soil pile for recovery.

5. The construction method according to claim 3, characterized in that: When constructing cement soil piles, the first lifting rod speed is 10-20cm / min, the first grouting pressure is 25-30MPa, the rotation speed of the nozzle is 10-20 rpm, the cement slurry is pure cement slurry with a water-cement ratio of 0.5-0.8, and the cement addition amount is 25-35%; When performing supplementary grouting, the second rod lifting speed is 18-30cm / min, and the second grouting pressure is 20-25MPa.

6. The construction method according to claim 3, characterized in that: When supplementary grouting is performed, the diffusion radius of the cement slurry is 30-50% of the radius of the enlarged head.

7. The construction method according to claim 3, characterized in that: The anchor plate is located within the diffusion radius of the cement slurry during supplementary grouting.

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