Spring-prestressed anchor rod and method of using same

Abstract

The present application relates to a kind of spring prestressed anchor rod and its use method, the spring prestressed anchor rod includes: hollow anchor rod, including free section and the anchoring section fixed to the one end of free section, the one end of free section away from anchoring section is equipped with grouting port, the one end of anchoring section away from the free section is equipped with grouting outlet, and the rod body of free section is distributed with multiple through holes;Spring is sleeved in free section, and the both ends of spring are respectively fixed with first, second backing plate, first backing plate is movably sleeved in the position of free section relatively close to grouting port, and second backing plate is sleeved and fixed at the junction of free section and anchoring section;For driving first backing plate to move to realize the expansion and contraction of spring, the both ends of pull rod are formed into bidirectional screw thread section, and first, second backing plate is equipped with a pair of bidirectional screw thread hole for bidirectional screw thread section screw connection respectively.This application applies prestress by spring, makes soil consolidation more dense, not easy to fall off, reduces deformation, and guarantees construction quality.

Description

Technical Field

[0001] This invention relates to the field of foundation pit support, and in particular to a spring prestressed anchor rod and its application method. Background Technology

[0002] With the continuous development of construction technology, conventional construction techniques such as deep foundation pit slope excavation and slope support, shallow buried tunneling method for soft soil reinforcement, and pile foundation retaining structure reinforcement, leakage plugging, and deformation control use hollow steel pipes for grouting to consolidate the soil. However, due to the characteristics of the project and the structural reasons of the anchor rod itself, problems such as insufficient reinforcement, loosening and falling off, excessive deformation, and excessively long required anchoring depth are prone to occur. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a spring-prestressed anchor rod and its application method. This spring-prestressed anchor rod applies prestress through a spring, making the soil more compacted, less prone to falling off, reducing deformation, and ensuring construction quality.

[0004] This invention is achieved through the following solution: a spring prestressed anchor bolt, comprising:

[0005] A hollow anchor rod includes a free section and an anchoring section fixed to one end of the free section. The free section is provided with a grouting port at the end away from the anchoring section, and the anchoring section is provided with a grout outlet at the end away from the free section. Multiple through holes are arranged on the rod body of the free section.

[0006] A spring is fitted onto the free section, with a first pad and a second pad fixed at both ends of the spring, the first pad being movably fitted onto the free section and positioned relatively close to the grouting port, and the second pad being fitted onto and fixed at the connection between the free section and the anchoring section.

[0007] A pull rod is used to drive the first pad to move and to extend or retract the spring by changing the distance between the first pad and the second pad. The two ends of the pull rod are formed as bidirectional threaded sections. The first pad and the second pad are provided with a pair of bidirectional threaded holes for the bidirectional threaded sections to be screwed together.

[0008] A further improvement of the spring prestressed anchor rod of the present invention is that the number of tie rods is at least three, and they are evenly spaced on the outer periphery of the spring, and the first pad and the second pad are provided with at least three pairs of bidirectional threaded holes corresponding one-to-one with the at least three tie rods.

[0009] A further improvement of the spring prestressed anchor rod of the present invention is that a grouting check sleeve is detachably fitted at the grouting port of the free section, and the size of the grouting check sleeve is such that it abuts against the first pad when the spring is stretched.

[0010] A further improvement of the spring prestressed anchor rod of the present invention is that it further includes a fastening nut, wherein the portion of the free section extending out of the first pad when the spring is in a compressed state is provided with an external thread for the fastening nut to be screwed into.

[0011] A further improvement of the spring prestressed anchor rod of the present invention is that a trumpet head for diffusing grout is sleeved at the grout outlet of the anchoring section.

[0012] A further improvement of the spring prestressed anchor rod of the present invention is that multiple through holes are also provided on the rod body of the anchoring section.

[0013] A further improvement of the spring prestressed anchor rod of the present invention is that the through hole is a quincunx-shaped hole.

[0014] This invention also provides a method for using a spring prestressed anchor bolt, comprising the following steps:

[0015] Tighten the pull rod to move the first pad away from the second pad, and stop tightening the pull rod after the spring is in a stretched state.

[0016] Grout is injected into the hollow anchor rod through the grouting port, and the grout flows out from the grout outlet and the through hole;

[0017] Once the spring is gripped and solidified by the slurry, continue to twist the pull rod to disengage it from the first pad and the second pad, and then retract the pull rod.

[0018] A further improvement to the method of using the spring prestressed anchor rod of the present invention is as follows:

[0019] After grouting into the hollow anchor rod, a grouting check sleeve is fitted at the grouting port and the grouting check sleeve is pressed against the first pad.

[0020] After the spring is gripped and solidified by the grout, first remove the grouting check sleeve, and then continue to tighten the pull rod.

[0021] A further improvement to the method of using the spring prestressed anchor rod of the present invention is as follows:

[0022] The spring prestressed anchor rod also includes a fastening nut, and the free section is provided with external threads;

[0023] Before using the spring prestressed anchor rod, screw the fastening nut onto the external thread of the free section and tighten the fastening nut to bring the spring to a reset or compressed state.

[0024] The spring prestressed anchor rod of this invention, through its structural design of spring, hollow anchor rod, and tie rod, uses the tie rod to keep the spring in a stretched state before grouting. After the spring is solidified, the tie rod is removed, causing the spring to generate an inward contraction force, thereby reinforcing the soil and generating tension in the surrounding soil. This reduces the required anchorage length of the anchor rod, making the soil consolidation denser, less prone to falling off, reducing deformation, and ensuring construction quality. It is more suitable for reinforcing soft strata and can also be used for construction processes such as reinforcement, leak sealing, and deformation control of pile foundation retaining structures. Attached Figure Description

[0025] Figure 1 A schematic diagram of the overall structure of an embodiment of the spring prestressed anchor rod of the present invention is shown. Detailed Implementation

[0026] To address the problems of insufficient reinforcement, loosening and detachment, excessive deformation, and excessively long anchoring depth associated with traditional anchor bolts, this invention provides a spring-prestressed anchor bolt and its application method. This spring-prestressed anchor bolt applies prestress through a spring, resulting in denser soil consolidation, reduced detachment, and less deformation, thus ensuring construction quality. The following detailed description, in conjunction with accompanying drawings, further illustrates this spring-prestressed anchor bolt and its application method.

[0027] See Figure 1 As shown, a spring prestressed anchor rod includes: a hollow anchor rod 1, which includes a free section and an anchoring section fixed to one end of the free section. The free section is provided with a grouting port 11 at the end away from the anchoring section, and the anchoring section is provided with a grout outlet 12 at the end away from the free section. The free section has multiple through holes 13. A spring 2 is sleeved on the free section. A first pad 3 and a second pad 4 are fixed to both ends of the spring 2, respectively. The first pad 3 is movably sleeved on the free section and is relatively close to the grouting port 11. The second pad 4 is sleeved and fixed at the connection between the free section and the anchoring section. A pull rod 5 is used to drive the first pad 3 to move and to realize the extension and retraction of the spring 2 by changing the distance between the first pad 3 and the second pad 4. The two ends of the pull rod 5 are formed as bidirectional threaded sections. The first pad 3 and the second pad 4 are provided with a pair of bidirectional threaded holes for the bidirectional threaded sections to be screwed together. Through the corresponding connection of the bidirectional threaded hole and the bidirectional threaded section, the pull rod 5 can adjust the distance between the first pad 3 and the second pad 4, and can provide the supporting force to prevent the spring 2 from rebounding when it is stretched.

[0028] Specifically, both the first pad 3 and the second pad 4 are rectangular pads with openings in the center. The hollow anchor rod 1 passes through the two openings and is fixed to the second pad 4. The first pad 3 can move axially relative to the hollow anchor rod 1. There are four tie rods 5, and the four tie rods 5 are located between the four corners of the first pad 3 and the second pad 4. The four corners of the first pad 3 and the second pad 4 are provided with four pairs of bidirectional threaded holes corresponding to the four tie rods 5. The spring is a high-strength spring, and the lengths of the spring 2, the tie rods 5, and the free section are such that the spring 2 can be stretched between its shortest and longest states by turning the tie rods 5. When the spring 2 is stretched to its longest state, the free section can still extend beyond the first pad 3 by a certain length.

[0029] Preferably, a grouting check sleeve is detachably fitted at the grouting port 11 of the free section (i.e., the portion of the free section from which the first pad 3 extends), and the size of the grouting check sleeve is such that it abuts against the first pad 3 when the spring 2 is stretched. The grouting check sleeve is fitted after grouting to prevent grout backflow.

[0030] Preferably, the spring prestressed anchor bolt further includes a fastening nut 7, and the portion of the free section extending from the first washer 3 when the spring 2 is in a compressed state has external threads for the fastening nut 2 to engage. This allows the first washer 3 to be limited by the fastening nut 2 when the spring prestressed anchor bolt is not used, preventing the first washer 3 from coming out of the hollow anchor bolt 1 in the event of damage to the tie rod 5 or stripping of the threads.

[0031] Preferably, a funnel head 6 for dispersing grout is fitted at the grout outlet 12 of the anchoring section, so that the grout injected into the hollow anchor rod 1 can flow out and spread quickly.

[0032] Preferably, the anchoring section also has multiple through holes 13. This allows for a tighter connection between the anchoring section of the hollow anchor rod 1 and the surrounding soil, thereby increasing the anchoring strength.

[0033] Preferably, all the aforementioned through holes 13 are evenly spaced and are in a quincunx pattern.

[0034] A method for using spring prestressed anchor bolts, in conjunction with Figure 1 As shown, the steps include:

[0035] Step 1: Twist the lever 5 to move the first pad 3 away from the second pad 4, and stop twisting the lever 5 after the spring 2 is in a stretched state.

[0036] Step 2: Grout is injected into the hollow anchor rod 1 through the grouting port 11, so that the grout flows out from the grout outlet 12 and the through hole 13.

[0037] Step 3: After the spring 2 is gripped and solidified by the slurry, continue to twist the pull rod 5 to disengage it from the first pad 3 and the second pad 4, and then retract the pull rod 5.

[0038] Preferably: after grouting into the hollow anchor rod 1, a grouting check sleeve is fitted at the grouting port 11 and the grouting check sleeve is made to abut against the first pad 3; after the spring 2 is gripped and solidified by the grout, the grouting check sleeve is removed first, and then the tie rod 5 is continued to be screwed on.

[0039] Preferably, the spring prestressed anchor also includes a fastening nut 7, and the free section has external threads. Before using the spring prestressed anchor, the fastening nut 7 is screwed onto the external threads of the free section and tightened to put the spring 2 into a reset or compressed state. This prevents the first pad 3 from coming out of the hollow anchor 1 in case the tie rod 5 is damaged or the threads are stripped, and also prevents the tensile force of the spring 2 from being affected.

[0040] This invention is widely used in deep foundation pit slope protection, shallow buried tunneling reinforcement of weak strata, reinforcement of pile foundation retaining structures, leak sealing, and enhancing the ability of anchor bolts to resist stratum deformation. By adjusting the tie rod to control the tension and compression of the high-strength spring, the spring is in a stretched state before grouting, and the tie rod is removed after the spring has solidified, causing the spring to generate an inward contraction force, thereby reinforcing the soil, generating tension in the surrounding soil, reducing the required anchorage length of the anchor bolt, making the soil more compact and less prone to falling off, reducing deformation, and ensuring construction quality.

[0041] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. A spring-prestressed anchor bolt, characterized in that, include: A hollow anchor rod includes a free section and an anchoring section fixed to one end of the free section. The free section is provided with a grouting port at the end away from the anchoring section, and the anchoring section is provided with a grout outlet at the end away from the free section. Multiple through holes are arranged on the rod body of the free section. A spring is fitted onto the free section, with a first pad and a second pad fixed at both ends of the spring, the first pad being movably fitted onto the free section and positioned relatively close to the grouting port, and the second pad being fitted onto and fixed at the connection between the free section and the anchoring section. A pull rod is used to drive the first pad to move and to extend or retract the spring by changing the distance between the first pad and the second pad. The two ends of the pull rod are formed with bidirectional threaded sections. The first pad and the second pad are each provided with a pair of bidirectional threaded holes for the bidirectional threaded sections to be screwed together. When grout is injected into the hollow anchor rod through the grouting port, the grout can flow out from the grout outlet and the through hole, thereby causing the spring to be gripped and solidified by the grout.

2. The spring-prestressed anchor bolt as described in claim 1, characterized in that, The number of pull rods is at least three, and they are evenly spaced on the outer periphery of the spring. The first pad and the second pad are provided with at least three pairs of bidirectional threaded holes corresponding to the at least three pull rods.

3. The spring-prestressed anchor bolt as described in claim 1, characterized in that, A grouting check sleeve is detachably fitted at the grouting port of the free section, and the size of the grouting check sleeve is such that it abuts against the first pad when the spring is stretched.

4. The spring-prestressed anchor bolt as described in claim 1, characterized in that, It also includes a fastening nut, and the portion of the free section extending out of the first pad when the spring is in a compressed state has external threads for the fastening nut to engage.

5. The spring-prestressed anchor bolt as described in claim 1, characterized in that, The grout outlet of the anchoring section is fitted with a trumpet-shaped head for diffusing the grout.

6. The spring-prestressed anchor bolt as described in claim 1, characterized in that, The anchoring section also has multiple through holes on its rod.

7. The spring-prestressed anchor bolt as described in claim 1 or 6, characterized in that, The through hole is a plum blossom-shaped hole.

8. A method of using the spring prestressed anchor bolt as described in claim 1, characterized in that, Including the following steps: Tighten the pull rod to move the first pad away from the second pad, and stop tightening the pull rod after the spring is in a stretched state. Grout is injected into the hollow anchor rod through the grouting port, and the grout flows out from the grout outlet and the through hole; Once the spring is gripped and solidified by the slurry, continue to twist the pull rod to disengage it from the first pad and the second pad, and then retract the pull rod.

9. The method of using the spring prestressed anchor bolt as described in claim 8, characterized in that: After grouting into the hollow anchor rod, a grouting check sleeve is fitted at the grouting port and the grouting check sleeve is pressed against the first pad. After the spring is gripped and solidified by the grout, first remove the grouting check sleeve, and then continue to tighten the pull rod.

10. The method of using the spring prestressed anchor bolt as described in claim 8, characterized in that: The spring prestressed anchor rod also includes a fastening nut, and the free section is provided with external threads; Before using the spring prestressed anchor rod, screw the fastening nut onto the external thread of the free section and tighten the fastening nut to bring the spring to a reset or compressed state.

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