Pressurized grouting prestressed hollow anchor rod and mounting method thereof

Abstract

The invention discloses an under-pressure grouting prestressed hollow anchor rod and a mounting method thereof. The under-pressure grouting prestressed hollow anchor rod comprises a hollow rod body, a stirring cutter arranged at the front end of the hollow rod body, and a stop-grouting plug, a base plate, a spherical washer and a nut which are sequentially arranged at the tail part of the hollow rod body, a conical sealing belt is arranged on the grout stopping plug, and a supporting ring is arranged at the large end of the conical sealing belt. Compared with the prior art, the grouting stopping plug has the advantages that the grouting stopping plug of a brand new structure can be installed in anchor holes of different sizes, the installation resistance of the grouting stopping plug is small, the return resistance of the grouting stopping plug is large, and the grouting stopping effect is guaranteed; the whole stop-grouting plug is of a solid structure, interference sealing is formed between the stop-grouting plug and a rod body and an anchor hole during installation, pressurization is achieved, and the grouting compactness is guaranteed. The stirring cutter with a brand-new structure not only ensures sufficient stirring of an anchoring agent, but also can prevent the anchoring agent from flowing back into the rod body.

Description

Technical Field

[0001] The present invention relates to a pressure grouting prestressed hollow anchor rod and an installation method thereof, which are applicable to engineering fields such as traffic tunnels with special requirements for the grouting density of anchor rods. Background Art

[0002] In the construction of traffic tunnels under complex geological conditions such as plateau railways, the rapid construction and reliability of the surrounding rock support system are directly related to project safety and construction progress. As the core product of the support system, higher requirements are put forward for the installation efficiency and grouting density of prestressed hollow anchor rods. The currently widely used bonded anchorage type prestressed hollow anchor rod pierces the components by welding and stirs the anchoring agent during the installation process. However, due to the simple structure of the piercing components, the piercing and stirring effects of the anchoring agent are not good, and the pierced anchoring agent is easy to flow back into the rod body, resulting in less anchoring agent outside the rod body. Insufficient pre-tightening force can be applied in the early stage to balance the mechanical pressure when pumping cement mortar in the later stage, resulting in the failure of anchor rod installation. Moreover, there is a problem that the piercing components cannot be universally matched with different rod bodies. Therefore, there is an urgent need for a structure that can not only achieve the piercing and stirring of the anchoring agent but also prevent the anchoring agent from flowing back, improve the stirring effect of the anchoring agent, and provide pre-tightening force for the anchor rod to balance the mechanical pressure during grouting. Therefore, although these two types of anchor rods can achieve mechanized construction at present, their construction efficiency and success rate are not high, there are potential safety hazards, and the project progress is seriously affected. Summary of the Invention

[0003] In order to overcome the above-mentioned disadvantages of the prior art, the present invention proposes a pressure grouting prestressed hollow anchor rod and an installation method thereof.

[0004] The technical solution adopted by the present invention to solve its technical problems is: a pressure grouting prestressed hollow anchor rod, which includes a hollow rod body, a stirring blade arranged at the front end of the hollow rod body, and a grout stop plug, a backing plate, a spherical washer and a nut arranged in sequence at the tail of the hollow rod body; a conical sealing band is arranged on the grout stop plug, and a support ring is arranged at the large end of the conical sealing band.

[0005] Further, the grout stop plug is tightly installed with the hollow rod body through internal threads.

[0006] Further, the front end of the stirring blade is a sharp piercing device.

[0007] Further, a spiral stirring device is arranged on the stirring blade.

[0008] Further, the stirring blade is threadedly connected with the internal thread of the hollow rod body through a connecting device with external threads at its tail.

[0009] Further, the grout stop plug is made of rubber or other soft materials as a whole.

[0010] Further, the grout plug is an integral solid structure, and when installed, it forms an interference seal with the hollow rod body and the anchor hole.

[0011] Further, a slurry outlet hole is provided at the front end of the hollow rod body.

[0012] The present invention also provides an installation method for a prestressed hollow anchor rod with pressure grouting, including the following steps:

[0013] Step 1: Place the assembled anchor rod into the anchor rod library of the anchor rod trolley, with the end equipped with the stirring blade facing forward;

[0014] Step 2: After drilling, install the resin anchoring agent at the bottom of the anchor hole;

[0015] Step 3: Install the anchor rod: Use the manipulator of the anchor rod trolley to grasp the anchor rod, align the end equipped with the stirring blade with the anchor hole, dock the inner sleeve in the trolley with the tail of the anchor rod, and drive the trolley forward to push the anchor rod to the bottom of the anchor hole;

[0016] Step 4: Stir the anchoring agent: Drive the inner sleeve of the anchor rod trolley to rotate left, and the outer sleeve follows. Drive the anchor rod to rotate and advance through the inner sleeve. During the advancement process, the stirring blade pierces the packaging of the anchoring agent and stirs the anchoring agent. Continue to advance the anchor rod to fill the anchoring agent between the rod body and the anchor hole;

[0017] Step 5: Pre-tighten: After waiting for the anchoring agent to solidify, drive the inner sleeve to retract and tension the anchor rod. After reaching the designed prestress value, drive the outer sleeve to rotate left and tighten the nut to press against the spherical washer to apply the pre-tightening force of the anchor rod;

[0018] Step 6: Grout: Pump the premixed cement mortar into the hollow rod body through the inner sleeve of the anchor rod trolley, and the cement mortar flows out from the slurry outlet hole reserved at the front end of the hollow rod body to achieve the grouting of the anchor rod.

[0019] Compared with the prior art, the positive effects of the present invention are:

[0020] 1. In the anchor rod structure of the present invention, the anchor rod fittings are all matched with the hollow rod body through threaded connections, which is convenient for assembly and the product structure is simple.

[0021] 2. The present invention designs a grouting plug with a brand-new structure. The grouting plug is provided with a conical sealing belt, which can be installed in anchor holes of different sizes, so that the installation resistance of the grouting plug is small and the retreat resistance is large. When installing the anchor rod and stirring the anchor agent, an interference fit is formed between the rod body, the grouting plug and the anchor hole, and the grouting plug is installed in the anchor hole; when grouting, after the mortar fills the anchor hole space at the front end of the grouting plug, continuous grouting will push the grouting plug backward until the grouting plug exits the anchor hole, thereby ensuring the grouting effect and grouting density; the grouting plug is provided with a support ring. During the grouting process, the grouting plug retreats until the grouting plug exits the anchor hole and the support ring passes through the center hole of the pad to resist the spherical gasket, thereby avoiding excessive retreat of the grouting plug and affecting the grouting effect; the grouting plug is provided with an internal thread, which can prevent leakage of grout after tightly fitting with the rod body; the grouting plug is a solid structure as a whole, and forms an interference seal with the rod body and the anchor hole during installation to achieve pressurization, thereby ensuring the overall effect of grouting.

[0022] 3. The present invention designs a stirring blade with a completely new structure. The piercing device at the head of the stirring blade can smoothly pierce the anchor packaging; the stirring device ensures sufficient stirring of the anchor; the connecting device cooperates with the internal thread of the hollow rod body, which not only prevents the stirring blade from detaching from the hollow rod body during installation, but also seals the hollow rod body to prevent the anchor from flowing back into the rod body. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0024] Figure 1 It is a structural schematic diagram of the prestressed hollow anchor rod with pressure grouting of the present invention;

[0025] Figure 2 It is a schematic diagram of the installation process of the pressure grouting prestressed hollow anchor rod of the present invention;

[0026] Figure 3 It is a schematic diagram of anchoring agent stirring;

[0027] Figure 4 It is a schematic diagram of the grouting process of the present invention;

[0028] The reference numerals in the figure include: agitator 1, slurry outlet hole 2, hollow rod body 3, slurry stop plug 4, pad 5, spherical washer 6, nut 7, resin anchor 8. DETAILED DESCRIPTION

[0029] A prestressed hollow anchor rod with pressure grouting, such as Figure 1 As shown, it includes: a stirring blade 1, a pulp outlet hole 2, a hollow rod body 3, a pulp stopper 4, a pad 5, a spherical washer 6, and a nut 7, wherein:

[0030] A stirring blade 1 is arranged at the front end of the hollow rod body 3, a slurry stopper 4, a pad 5, a spherical washer 6 and a nut 7 are arranged in sequence at the tail end of the hollow rod body 3, and a slurry outlet hole 2 is arranged at the front middle position of the hollow rod body 3.

[0031] The tail of the stop plug 4 is provided with a conical sealing belt, and a support ring is provided at the large end of the conical sealing belt. The stop plug 4 is made of rubber or other soft materials as a whole, and can be deformed to match anchor holes of different diameters to achieve a sealing effect and prevent leakage. The support ring provided at the large end of the conical sealing belt is used to resist other accessories on the hollow rod body to prevent the stop plug from retreating; the stop plug is provided with an internal thread, and is assembled with the hollow rod body 3 through threaded cooperation. The whole is a solid structure. When the pre-tightening force is applied, the squeezed stop plug is pressed inward against the hollow rod body to ensure the stop effect.

[0032] The present invention designs an assembleable stirring blade structure, wherein the front end of the stirring blade 1 is a sharp piercing device; the middle position is a spiral stirring device; and the tail end is a connecting device with an external thread.

[0033] The present invention also provides a method for installing a prestressed hollow anchor rod by pressure grouting, comprising the following steps:

[0034] Step 1: Anchor assembly. Figure 1 The structure is used to assemble the anchor rods, and the assembled anchor rods are placed in the anchor rod warehouse of the anchor rod trolley, with the end equipped with the stirring knife facing forward.

[0035] Step 2: Drilling.

[0036] Step 3: Install the resin anchor 8 at the bottom of the anchor hole.

[0037] Step 4: Install the anchor rod. Use the anchor rod trolley manipulator to grab the anchor rod, align the end equipped with the stirring knife with the anchor hole, dock the inner sleeve of the trolley with the tail of the anchor rod, and push the anchor rod to the bottom of the anchor hole. Figure 2 shown.

[0038] Step 5: Stir the anchoring agent. Drive the anchor trolley to rotate the inner sleeve and the outer sleeve to follow the rotation. The inner sleeve drives the anchor (left-handed thread) to rotate left and advance. During the advancement process, the stirring blade 1 destroys the anchoring agent packaging. Continue to advance the anchor and stir the anchoring agent so that the anchoring agent is filled between the rod body and the anchor hole. Figure 3 shown.

[0039] Step 6: Pre-tightening. After the anchoring agent solidifies, drive the inner sleeve back to tension the anchor rod. After the designed prestress value is reached, drive the outer sleeve to tighten the nut 7 to the left and press against the spherical washer 6 to achieve the application of anchor rod pre-tightening force.

[0040] Step 7: Grouting. The mortar is pumped into the hollow rod through the inner sleeve and flows out from the grouting hole 2 at the front end of the rod to achieve grouting of the anchor rod.Figure 4 as shown

Claims

1. A prestressed hollow anchor rod with pressure grouting, characterized in that: It includes a hollow rod body, a mixing cutter arranged at the front end of the hollow rod body, and a grout stopper, a backing plate, a spherical washer and a nut arranged in sequence at the tail of the hollow rod body; a conical sealing band is arranged on the grout stopper, and a support ring is arranged at the large end of the conical sealing band.

2. The prestressed hollow anchor rod with pressure grouting according to claim 1, wherein: The grout stopper is tightly fitted and installed with the hollow rod body through internal threads.

3. The prestressed hollow anchor rod with pressure grouting according to claim 1, characterized in that: The front end of the mixing cutter is a sharp puncturing device.

4. The prestressed hollow anchor rod with pressure grouting according to claim 3, characterized in that: A spiral mixing device is arranged on the mixing cutter.

5. The prestressed hollow anchor rod with pressure grouting according to claim 3, characterized in that: The mixing cutter is threadedly connected with the internal thread of the hollow rod body through a connecting device with external threads at its tail.

6. The prestressed hollow anchor rod with pressure grouting according to claim 1, characterized in that: The whole grout stopper is made of rubber or other soft materials.

7. A pressure grouting prestressed hollow anchor rod according to claim 6, characterized in that: The whole grout stopper is of a solid structure and forms an interference seal with the hollow rod body and the anchor hole during installation.

8. A prestressed hollow anchor rod with pressure grouting according to claim 1, characterized in that: A slurry outlet hole is arranged at the front end of the hollow rod body.

9. An installation method of a prestressed hollow anchor rod with pressure grouting, characterized in that: It includes the following steps: Step 1: Place the assembled anchor rod into the anchor rod bin of the anchor rod trolley, with the end equipped with the mixing cutter facing forward; Step 2: Install the resin anchoring agent at the bottom of the anchor hole after drilling; Step 3: Install the anchor rod: Use the manipulator of the anchor rod trolley to grab the anchor rod, align the end equipped with the mixing cutter with the anchor hole, dock the inner sleeve in the trolley with the tail of the anchor rod, and drive the trolley forward to push the anchor rod to the bottom of the anchor hole; Step 4: Stir the anchoring agent: Drive the inner sleeve of the anchor rod trolley to rotate left, and the outer sleeve follows. Drive the anchor rod to rotate and advance through the inner sleeve. During the advancing process, the mixing cutter punctures the packaging of the anchoring agent and stirs the anchoring agent, and continue to advance the anchor rod to make the anchoring agent fill between the rod body and the anchor hole; Step 5: Pre-tightening: After waiting for the anchoring agent to solidify, drive the inner sleeve to retract and tension the anchor rod. After reaching the designed prestress value, drive the outer sleeve to rotate left to tighten the nut against the spherical washer to apply the pre-tightening force of the anchor rod; Step 6: Grouting: Pump the premixed cement mortar into the hollow rod body through the inner sleeve of the anchor rod trolley, and the cement mortar flows out from the slurry outlet hole reserved at the front end of the hollow rod body to realize the grouting of the anchor rod.

10. The installation method of a pressure grouting prestressed hollow anchor rod according to claim 9, characterized in that: In Step 3, when installing the anchor rod, the whole grout stopper is completely inserted into the anchor hole.

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