Cylindrical branch disc type anchoring structure

Abstract

The invention is suitable for the technical field of anchoring structures, and provides a cylindrical branch disc type anchoring structure which comprises an anchor head, a pull rod, a free section and an anchoring section. The anchor head comprises an anchorage device, a bearing plate and a supporting column. The pull rod comprises a steel bar and a centering bracket; the anchoring section comprises a straight anchoring section and a branch disc anchoring section, and a plurality of cylindrical branch discs are arranged on the branch disc anchoring section at intervals. The supporting disc anchoring structure can obviously enhance uplift bearing capacity and effectively control displacement, and is particularly suitable for anchoring engineering projects with high requirements for displacement control. On the premise of meeting the requirement of anchoring force design, the anchoring structure can effectively shorten the length of the anchor rod, consumables are reduced, and remarkable economic benefits are achieved; according to soil layer conditions, engineering requirements and the like, the anchoring structure can flexibly adjust the disc number, the disc diameter, the disc distance and the like and is high in applicability.

Description

Technical Field

[0001] The invention belongs to the technical field of anchoring structures, and in particular relates to a cylindrical support plate type anchoring structure. Background Art

[0002] Anchors are structures used to secure structures (such as buildings, bridges, tunnel linings, etc.) to a more stable base (such as concrete foundations, rock, etc.). They are widely used in civil engineering and construction projects to provide additional support and stability, especially when resistance to tension, uplift or shear forces is required.

[0003] How to increase the pull-out bearing capacity of anchor rods within the effective length has always been the focus of research by scholars at home and abroad. Existing studies have shown that increasing the force-bearing area of ​​the inner end of the anchor rod is one of the important measures to improve the bearing capacity of the anchor rod, so some scholars have proposed a branch plate anchoring structure. However, due to the conical shape of the branch plate of the traditional branch plate anchoring structure, the force on the end of the branch plate is weak, causing the anchor rod to shear prematurely, thus failing to fully mobilize the anchoring effect of the branch plate end. Therefore, in order to prevent the branch plate anchor rod from shearing prematurely at the branch plate, a cylindrical branch plate anchoring structure is improved on the basis of the traditional branch plate anchoring structure to improve the pull-out bearing capacity of the anchor rod. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a cylindrical support plate type anchoring structure, aiming to solve the problems raised in the above-mentioned background technology.

[0005] The embodiment of the present invention is implemented as follows: a cylindrical support plate type anchoring structure includes an anchor head, a pull rod, a free section and an anchoring section; The anchor head comprises an anchor, a pressure-bearing plate and a support column; The tie rod includes a steel bar and a centering bracket; The anchoring section includes a straight anchoring section and a branch plate anchoring section. A number of cylindrical branch plates are arranged at intervals on the branch plate anchoring section. The aperture of the cylindrical branch plate is larger than the aperture of the straight anchoring section. The front end of the pull rod passes through the node of the support column. The anchor and the pressure plate are loaded on the pull rod from front to back in sequence. The pressure plate is against the support column. The anchor locks the pressure plate, the pull rod and the support column. The branch plate anchoring section is filled with grouting material.

[0006] According to a further technical solution, the grouting material is high-strength, low-shrinkage cement mortar.

[0007] According to a further technical solution, the free section is provided with a flexible PVC sleeve.

[0008] According to a further technical solution, the centering bracket has at least three radially extending support arms.

[0009] According to a further technical solution, the support arm is provided with an elastic gasket for contacting the anchor hole wall.

[0010] In a further technical solution, the angle between the anchor structure and the horizontal plane is α It is 15°~30°.

[0011] According to a further technical solution, the construction method of the cylindrical support plate type anchoring structure comprises the following steps: Step 1: Preparation before construction; Measure and locate the anchor holes, and level and clean the site; Step 2: Preliminary opening; Use a drilling rig to pre-drill anchor holes, and then test the hole diameter and depth after drilling; Step 3: Expand the hole; Use a hole enlarging device to enlarge the pre-formed anchor hole at a specific depth, repeat the operation until multiple branch plate cavities are formed, and then inspect the hole shape after completion; Step 4: First grouting; Use grouting equipment to pour cement mortar into the hole, and return the mortar from the bottom of the hole upwards, until all the mud and soil in the hole are returned to the outside of the hole, until the hole is full and the original mortar emerges from the hole mouth; Step 5: Place the tie rod; Lower the anchoring section and free section into the anchor hole at a uniform speed until they reach the designed depth, keeping the whole section centered; Step 6: Second grouting; After the device is placed in place, the second grouting is carried out, with grout returning from the bottom of the hole upwards. The grouting is stopped after the hole is full and the original grout emerges from the hole mouth; Step 7: Tighten the anchor rod; After the cement mortar has initially solidified, the bearing plate and anchor are installed, tensioned and locked to achieve the designed anchoring force.

[0012] A cylindrical branch plate type anchoring structure provided by an embodiment of the present invention can significantly enhance the pull-out bearing capacity and effectively control the displacement, and is particularly suitable for anchoring engineering projects with high requirements for displacement control; on the premise of meeting the requirements of the anchoring force design, the anchoring structure can effectively shorten the length of the anchor rod, reduce consumables, and has significant economic benefits; according to the soil layer conditions and engineering requirements, the anchoring structure can flexibly adjust the number of plates, plate diameters, and plate spacing, and has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic structural diagram of a cylindrical support plate type anchoring structure provided by an embodiment of the present invention; Figure 2 A construction flow chart of a cylindrical support plate type anchoring structure provided by an embodiment of the present invention; Figure 3The load-displacement curves of different branch plate shapes in the cylindrical branch plate anchor pull-out model test; Figure 4 The load-displacement curves of different numbers of branches in the cylindrical branch-plate anchor pull-out model test; Figure 5 The load-displacement curves of different branch plate diameters in the cylindrical branch plate anchor pull-out model test.

[0014] In the attached figure: 1-rebar; 2-PVC casing; 3-centering bracket; 4-elastic gasket; 5-grouting material; 6-cylindrical support plate; 7-free section; 8-anchor section; 9-pressure plate; 10-support column; 11-anchor. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0016] The specific implementation of the present invention is described in detail below in conjunction with specific embodiments.

[0017] like Figure 1 As shown in the figure (the outer edge contour of the oblique section line in the figure is the boundary of the local section view and is only used for illustration), a cylindrical branch plate type anchoring structure provided by an embodiment of the present invention includes an anchor head, a pull rod, a free section and an anchoring section; The anchor head comprises an anchor 11, a pressure plate 9 and a support column 10; The tie rod comprises a steel bar 1 and a centering bracket 3; The anchoring section 8 includes a straight anchoring section and a branch plate anchoring section. A number of cylindrical branch plates 6 are arranged at intervals on the branch plate anchoring section. The aperture of the cylindrical branch plate 6 is larger than the aperture of the straight anchoring section. The front end of the pull rod passes through the node of the support column 10. The anchor 11 and the pressure plate 9 are loaded on the pull rod from front to back in sequence. The pressure plate 9 is against the support column 10. The anchor 11 locks the pressure plate 9, the pull rod and the support column 10. The branch plate anchoring section is filled with grouting material 5.

[0018] As a preferred embodiment of the present invention, the grouting material 5 is high-strength, low-shrinkage cement mortar.

[0019] As a preferred embodiment of the present invention, the free section is provided with a corrosion-resistant, high-strength and flexible PVC sleeve.

[0020] As a preferred embodiment of the present invention, the centering bracket 3 has at least three radially extending support arms.

[0021] As a preferred embodiment of the present invention, an elastic gasket 4 for contacting the anchor hole wall is provided on the support arm.

[0022] As a preferred embodiment of the present invention, the angle between the anchor structure and the horizontal plane is α It is 15°~30°.

[0023] like Figure 2 As shown, as a preferred embodiment of the present invention, the construction method of the cylindrical branch plate type anchoring structure comprises the following steps: Step 1: Preparation before construction; Measure and locate the anchor holes, and level and clean the site; Step 2: Preliminary opening; Use a drilling rig to pre-drill anchor holes, and then test the hole diameter and depth after drilling; Step 3: Expand the hole; Use a hole enlarging device to enlarge the pre-formed anchor hole at a specific depth, repeat the operation until multiple branch plate cavities are formed, and then inspect the hole shape after completion; Step 4: First grouting; Use grouting equipment to pour cement mortar into the hole, and return the mortar from the bottom of the hole upwards, until all the mud and soil in the hole are returned to the outside of the hole, until the hole is full and the original mortar emerges from the hole mouth; Step 5: Place the tie rod; Lower the anchoring section and free section into the anchor hole at a uniform speed until they reach the designed depth, keeping the whole section centered; Step 6: Second grouting; After the device is placed in place, the second grouting is carried out, with grout returning from the bottom of the hole upwards. The grouting is stopped after the hole is full and the original grout emerges from the hole mouth; Step 7: Tighten the anchor rod; After the cement mortar is initially solidified, the pressure plate 9 and the anchor 11 are installed and tensioned and locked to achieve the designed anchoring force.

[0024] In the embodiment of the present invention, under the same conditions, the support plate anchoring structure can significantly enhance the pull-out bearing capacity and effectively control the displacement, and is particularly suitable for anchoring engineering projects with high requirements for displacement control; on the premise of meeting the requirements of the anchoring force design, the anchoring structure can effectively shorten the length of the anchor rod, reduce consumables, and has significant economic benefits; according to the soil conditions and engineering requirements, the anchoring structure can flexibly adjust the number of plates, plate diameters, and plate spacing, and has strong applicability.

[0025] In order to verify the effectiveness of the device, an indoor model test was conducted on a cylindrical support plate anchor structure. The model test used a pulley-weight loading device to apply the upward pull force, and a dial indicator was installed on the anchor head to measure the displacement of the anchor rod. Loading tests were conducted on three groups of anchor rods of different types, different numbers of plates, and different diameters. The test results are shown in the figure. Figure 3-5 As shown, specifically: like Figure 3 As shown in the figure, the pull-out bearing capacity of the branch plate anchor is better than that of the equal-diameter anchor. However, the traditional branch plate anchor will suffer shear failure in advance in the later stage, so its later pull-out bearing capacity is lower than that of the cylindrical branch plate anchor.

[0026] like Figure 4 As shown in the figure, as the number of branches of the cylindrical branch plate type anchor increases, its pull-out bearing capacity is also constantly improving. This is because the increase in the number of branches has an embedding effect on the surrounding soil.

[0027] like Figure 5 As shown in the figure, as the diameter of the branch plate of the cylindrical branch plate anchor increases, the contact area between the branch plate and the surrounding soil continues to increase, resulting in an increase in the resistance at the plate end. Therefore, its pull-out bearing capacity is also improved.

[0028] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A cylindrical support plate type anchoring structure, characterized in that: It includes anchor head, tie rod, free section and anchoring section; The anchor head comprises an anchor, a pressure-bearing plate and a support column; The tie rod includes a steel bar and a centering bracket; The anchoring section includes a straight anchoring section and a branch plate anchoring section. A number of cylindrical branch plates are arranged at intervals on the branch plate anchoring section. The aperture of the cylindrical branch plate is larger than the aperture of the straight anchoring section. The front end of the pull rod passes through the node of the support column. The anchor and the pressure plate are loaded on the pull rod from front to back in sequence. The pressure plate is against the support column. The anchor locks the pressure plate, the pull rod and the support column. The branch plate anchoring section is filled with grouting material.

2. The cylindrical branch plate type anchoring structure according to claim 1, characterized in that: The grouting material is cement mortar.

3. The cylindrical branch plate type anchoring structure according to claim 1, characterized in that: The free section is provided with a flexible PVC sleeve.

4. The cylindrical branch plate type anchoring structure according to claim 1, characterized in that: The centering bracket is provided with at least three radially extending support arms.

5. The cylindrical branch plate type anchoring structure according to claim 4, characterized in that: The support arm is provided with an elastic gasket for contacting the anchor hole wall.

6. The cylindrical branch plate type anchoring structure according to claim 1, characterized in that: The angle between the anchoring structure and the horizontal plane α It is 15°~30°.

7. The cylindrical branch plate type anchoring structure according to any one of claims 1 to 6, characterized in that: The construction method of the cylindrical support plate type anchoring structure comprises the following steps: Step 1: Preparation before construction; Measure and locate the anchor holes, and level and clean the site; Step 2: Preliminary opening; Use a drilling rig to pre-drill anchor holes, and then test the hole diameter and depth after drilling; Step 3: Expand the hole; Use a hole enlarging device to enlarge the hole at the depth of the pre-formed anchor hole, repeat the operation until multiple branch plate cavities are formed, and then inspect the hole shape after completion; Step 4: First grouting; Use grouting equipment to pour cement mortar into the hole, and return the mortar from the bottom of the hole upwards, until all the mud and soil in the hole are returned to the outside of the hole, until the hole is full and the original mortar emerges from the hole mouth; Step 5: Place the tie rod; Lower the anchoring section and free section into the anchor hole at a uniform speed until they reach the designed depth, keeping the whole section centered; Step 6: Second grouting; After the device is placed in place, the second grouting is carried out, with grout returning from the bottom of the hole upwards. The grouting is stopped after the hole is full and the original grout emerges from the hole mouth; Step 7: Tighten the anchor rod; After the cement mortar has initially solidified, the bearing plate and anchor are installed, tensioned and locked to achieve the designed anchoring force.

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