WO2020151347A1

WO2020151347A1 - Prefabricated prestressed anchor structure

Info

Publication number: WO2020151347A1
Application number: PCT/CN2019/119338
Authority: WO
Inventors: 付文光; 孙军兰; 李新元; 何志勇; 程磊; 戴锦鸿; 高升坚
Original assignee: 深圳市地质环境研究院有限公司
Priority date: 2019-01-24
Filing date: 2019-11-19
Publication date: 2020-07-30
Also published as: CN209837018U; JP3235428U

Abstract

The present utility model relates to the technical field of prestressed anchors and disclosed is a prefabricated prestressed anchor structure, comprising a drilled hole and a core placed inside the drilled hole. The core comprises multiple anchor bars, a grout, and a grouting tube; one end of the anchor bar is embedded into the grout, and the other end of the anchor bar extends away from the grout; one end of the grouting tube is embedded into the grout; the grout has a bottom close to the bottom of the drilled hole; the grouting tube penetrates through the bottom of the grout; the other end of the grouting tube extends away from the grout; one end of the anchor bar and one end of the grouting tube are separately fixed into the grout. Because the core is prefabricated, the quality of the grout is effectively ensured, and the poor stability of the bearing capacity of the anchor caused by large discreteness of the bearing capacity of the anchor is avoided; in addition, an adequate bonding strength between the grout and the bar is effectively ensured, and under the action of the grout, the bar is protected and the corrosion resistance of the bar is improved.

Description

Prefabricated prestressed anchor rod structure

Technical field

The utility model relates to the technical field of prestressed anchor rod construction, in particular to a prefabricated prestressed anchor rod structure.

Background technique

In the field of civil construction engineering at home and abroad, the geotechnical anchoring technology with prestressed anchors as the core is widely used, and it is widely used in slope treatment, foundation pit support, underground structure anti-floating, tunnel and underground cavern reinforcement, and disaster Treatment and other projects; according to structural principles, prestressed anchor rods can be divided into two categories: tension type and pressure type.

technical problem

At present, the tensile anchor rod is formed by drilling, installing anchor bars, and grouting in the stratum. It is difficult to remove impurities such as water, soil, rock cuttings and mud in the borehole, and it is easy to partially adhere to the surface of the anchor bar. Defects such as slag or mud skin, no partial grout coating, and mud inclusions in the slurry; and the slurry is diluted to varying degrees by the water in the hole and cannot be vibrated after grouting, resulting in lower actual strength of the slurry. The strength of the slurry is unstable, which leads to low and unstable bond strength between the slurry and the anchor bar, and ultimately leads to low tensile strength of the anchor bar, unstable and large dispersion, and the anchor bar is susceptible to corrosion.

Pressure-type anchor rod, the end of the grouting pipe exceeds the inner anchor head, and the grout flows around under the inner anchor head during grouting, and is blocked by the inner anchor head. Impurities such as water, soil, rock debris and mud under the inner anchor head It is difficult to rule out clean and inclusion in the slurry, resulting in low and unstable strength of the slurry under the inner anchor head, which can easily lead to local compression damage, resulting in low and unstable anchor bearing capacity; at the same time, under the inner anchor head The anchor bar is connected to the inner anchor head by the anchor clamp. Although the full length of the anchor bar is wrapped by the isolation sleeve to form anti-corrosion protection, it is difficult to form effective anti-corrosion protection for the anchor clamp due to the poor slurry quality under the anchor head. As a result, the load-bearing capacity of the pressure-type anchor is very discrete and the corrosion resistance is not good.

Technical solutions

The purpose of the utility model is to provide a prefabricated prestressed anchor rod structure, which aims to solve the problem of poor anti-corrosion performance of the prestressed anchor rod in the prior art.

The utility model is realized in this way. The prefabricated prestressed anchor rod structure includes a drilled hole and a core placed inside the drilled hole. The core includes a plurality of anchor bars, a grout and a grouting pipe. One end of the grouting pipe is embedded in the slurry, the other end of the anchor bar extends in a direction away from the slurry, and one end of the grouting pipe is embedded in the slurry, and the slurry has a hole close to the bore At the bottom of the bottom, the grouting pipe penetrates the bottom of the slurry, the other end of the grouting pipe extends in a direction away from the slurry, and one end of the anchor bar and one end of the grouting pipe are respectively It is fixedly arranged with the slurry.

Further, a plurality of the anchor ribs are arranged at a circumferential interval along the grouting pipe.

Further, the distance between adjacent anchor bars is 10-60 mm, and the diameter of the anchor bars is 12-80 mm.

Further, the anchor bar includes an anchor section and a free section, the anchor section is in the slurry, the free section is provided with an isolation sleeve, the isolation sleeve surrounds the free section, and the isolation sleeve The inner end of the tube is embedded in the slurry.

Further, the range of the inner end of the isolation sleeve embedded in the slurry is 200-300 mm.

Further, one end of the grouting pipe is embedded in the middle of the slurry, and each of the anchor bars is arranged at a circumferential interval along the circumference of the grouting pipe.

Further, the prefabricated prestressed anchor rod structure includes a template member, each of the anchor bars and the grouting pipe is relatively fixed by lashing, and one end of each of the anchor bars and one end of the grouting pipe are respectively placed The core is formed by grouting and vibrating in the template; the diameter of the core is in the range of 60-150mm.

Further, the outer surface of the slurry is provided with transverse ribs, and the transverse ribs are spirally arranged on the outer surface of the slurry.

Further, the transverse ribs are arranged in an inclined shape.

Further, the core includes a steel mesh, the steel mesh is in the grout, the steel mesh is enclosed to form an enclosed space, and a plurality of the anchor bars and the grouting pipe are all located State the enclosed space.

Beneficial effect

Compared with the prior art, in the prefabricated prestressed anchor rod structure provided by the present invention, the core is prefabricated in the factory or construction site, the fabricated core is placed in the borehole, and the grouting pipe is used for grouting. Make the slurry and the soil bond; due to the prefabrication of the core, the quality of the slurry is effectively guaranteed, and the dispersion of the bearing capacity of the anchor is prevented from being too large, resulting in poor stability of the bearing capacity of the anchor; in addition, the slurry and the reinforcement are effectively guaranteed The body has sufficient bonding strength, and, under the action of the slurry, it protects the reinforcement and improves the corrosion resistance of the reinforcement.

Description of the drawings

Figure 1 is a schematic plan view of a prefabricated prestressed anchor rod structure provided by an embodiment of the present invention;

2 is a schematic diagram of a section A of the prefabricated prestressed anchor rod structure provided by the embodiment of the present invention;

3 is a schematic diagram of the construction plan of the prefabricated prestressed anchor rod structure provided by the embodiment of the present invention;

4 is a schematic plan view of a prefabricated prestressed anchor rod structure provided by an embodiment of the present invention;

Fig. 5 is a schematic sectional view of part B of the prefabricated prestressed anchor rod structure provided by the embodiment of the present invention.

The best mode of the invention

In order to make the purpose, technical solutions and advantages of the present utility model clearer, the following further describes the present utility model in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present utility model, and are not used to limit the present utility model.

The same or similar reference numbers in the drawings of this embodiment correspond to the same or similar parts; in the description of the present invention, it should be understood that if there are the terms "upper", "lower", "left", "right" The orientation or positional relationship of other indications is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation and Therefore, the terms describing the positional relationship in the drawings are only used for exemplary description and cannot be understood as a limitation of the patent. For those of ordinary skill in the art, the specific meaning of the above terms can be understood according to the specific circumstances. .

The implementation of the present utility model will be described in detail below in conjunction with specific embodiments.

Referring to Figures 1-5, a preferred embodiment is provided for the utility model.

The prefabricated prestressed anchor rod structure provided by the utility model is used to solve the problems of low bearing capacity, instability and poor anti-corrosion performance of the prestressed anchor rod.

The prefabricated prestressed anchor rod structure includes a drilled hole and a core body 10, the core body 10 is placed inside the drilled hole, the core body 10 includes a plurality of anchor bars 11, a slurry 12 and a grouting pipe 13, and one end of the anchor bar 11 is embedded For the slurry 12, the other end of the anchor bar 11 extends away from the slurry 12, one end of the grouting pipe 13 is embedded in the slurry 12, and the slurry 12 has a bottom close to the bottom of the borehole, and the grouting pipe 13 penetrates the slurry. At the bottom of 12, the other end of the grouting pipe 13 is arranged to extend away from the slurry 12, and one end of the anchor rib 11 and one end of the grouting pipe 13 are fixedly arranged with the slurry 12, respectively.

In the above-mentioned prefabricated prestressed anchor rod structure, the core body 10 is prefabricated in the factory or the construction site. The prepared core body 10 is placed in the borehole, and the grouting pipe 13 is used for grouting to make the slurry 12 and the soil layer 30 bonding; due to the prefabrication of the core body 10, the quality of the slurry 12 is effectively ensured, and the dispersion of the bearing capacity of the bolt is prevented from being too large, resulting in poor stability of the bearing capacity of the bolt, and the overall bearing capacity is improved; in addition, the slurry is effectively guaranteed 12 has sufficient bonding strength with the bar to make it more stable, and under the action of the slurry 12, it protects the bar and improves the corrosion resistance of the bar.

In this embodiment, only one anchor bar 11 may also be used, and one or more anchor bars 11 are provided according to the design bearing capacity of the anchor bar 11 to ensure the overall stability of the core body 10 and at the same time. Reduce manufacturing costs.

The diameter of the borehole is greater than the diameter of the slurry 12 by more than 40 mm, which is convenient for the slurry 12 to be placed in the borehole and facilitates the installation of the anchor rod.

The material of the anchor bar 11 can be steel bars or steel strands, and the material of the slurry 12 can be fine stone concrete, cement mortar or cement paste; the price is low and the production speed is fast.

The multiple anchor bars 11 are arranged circumferentially and spaced along the grouting pipe 13; the use of multiple anchor bars 11 makes the overall anchoring effect stronger. At the same time, the multiple anchor bars 11 are arranged at intervals to make the overall anchoring force of the core 10 more uniform. In addition, the force of the slurry 12 is uniform, and the bearing capacity of the slurry 12 is provided.

The range of the distance between adjacent anchor bars 11 is 10-60 mm. With this arrangement, the matching effect of each anchor bar 11 is better and sufficient anchoring effect is ensured.

The diameter range of the anchor bar 11 is 12-80mm; the value range of the diameter of the anchor bar 11 is determined according to the design bearing capacity of each anchor bar 11, and the distance between each anchor bar 11 is 10-60mm; sufficient anchoring force is ensured.

The anchor bar 11 includes an anchor section and a free section. The anchor section is in the slurry 12. The free section is provided with an isolation sleeve 20 that surrounds the free section, and the inner end of the isolation sleeve 20 is embedded in the slurry 12; thereby enhancing isolation The installation stability of the casing 20, and ensures that the isolation casing 20 fully protects the free section, enhances the anti-corrosion performance of the free section, and improves the service life of the anchor bar 11.

In addition, when the grouting extends to the free section, under the action of the isolation sleeve 20, the isolation grouting is performed to ensure the tension of the free section.

The inner end of the isolation sleeve 20 is embedded in the slurry 12 in a range of 200-300 mm; waste of the isolation sleeve 20 is avoided, and at the same time, the installation stability of the isolation sleeve 20 is ensured.

One end of the grouting pipe 13 is embedded in the middle of the slurry 12, and the anchor bars 11 are arranged at a circumferential interval along the circumference of the grouting pipe 13; this makes the structure more compact, and when grouting is carried out through the grouting pipe 13, it is convenient for the cement slurry to be uniform Surround the core 10 to ensure the bonding effect between the core 10 and the soil layer 30.

The prefabricated prestressed anchor rod structure includes a template member. Each anchor bar 11 and the grouting pipe 13 are relatively fixed by lashing. One end of each anchor bar 11 and one end of the grouting pipe 13 are respectively placed in the template member for grouting and vibrating. , The core body 10 is formed; the manufacture of the core body 10 is facilitated, and the prefabrication of the core body 10 is realized.

The diameter of the core body 10 is in the range of 60-150 mm; the arrangement of each anchor bar 11 and the grouting tube 13 is ensured, and the core body 10 and the anchor rod have sufficient anti-deformation effect to improve the anchoring effect.

Furthermore, the outer surface of the slurry 12 is provided with stripes; the contact area between the slurry 12 and the soil layer 30 is enhanced, the bonding effect of the slurry 12 and the soil layer 30 is enhanced, and the anchoring effect of the core body 10 is improved.

The length of the core 10 is in the range of 2 to 3 m, and the strength of the slurry 12 is in the range of 20 to 50 MPa; it is ensured that the slurry 12 has sufficient anchoring stability.

A connecting channel is formed at the bottom of the slurry 12, the connecting channel is connected to the soil layer 30, and one end of the grouting pipe 13 is connected to the connecting channel; the grouting pipe 13 is realized for grouting.

The outer surface of the slurry 12 is provided with transverse ribs 14, which are arranged spirally on the outer surface of the slurry 12; under the action of the transverse ribs 14, the bonding strength of the slurry 12 is enhanced, and the Anchoring effect.

Furthermore, the transverse ribs 14 are arranged in an oblique shape to increase the transverse area of the transverse ribs 14 and improve the bonding strength of the slurry 12.

The core 10 includes a steel mesh 15 in the slurry 12, the steel mesh 15 encloses to form an enclosed space, and multiple anchor bars 11 and grouting pipes 13 are in the enclosed space; Under the action of 15, it helps to reduce the cracks of the slurry 12, thereby enhancing the anti-corrosion performance of the slurry 12 and protecting the slurry 12 from cracking.

Furthermore, the outer surface of the steel mesh 15 is provided with multiple horizontal strip groups, the two horizontal strip groups are arranged symmetrically along the center of the slurry; the horizontal strip group includes horizontally arranged rods, one end of the rod is connected to the steel mesh 15 On the outer surface of the rod, the other end of the rod body is in contact with the slurry 12; under the action of the rod body, it is convenient for the steel mesh 15 to be centered, which facilitates the installation of the steel mesh 15 and ensures the anti-cracking protection effect of the steel mesh 15.

One end of the rod is arranged in a movable connection with the outer surface of the steel mesh 15. After the steel mesh 15 is placed on the slurry 12, the rod is swung so that the other end of the rod conflicts with the slurry 12. At this time, the rod is arranged horizontally so that The steel mesh 15 and the slurry 12 are relatively fixed, so as to avoid the deviation of the steel mesh 15 during grouting, which affects the anti-cracking protection effect of the steel mesh 15.

In addition, the template can be used as a protective cover for the core 10 without being removed, thereby enhancing the anti-corrosion performance of the core 10.

The material of the slurry 12 can be fine stone concrete or mortar, thereby enhancing the bonding strength of the anchor bar and the slurry and enhancing the anti-corrosion performance.

The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Any modification, equivalent replacement and improvement made within the spirit and principle of the utility model shall be included in the present utility model. Within the scope of protection.

Claims

The prefabricated prestressed anchor rod structure is characterized in that it includes a drilled hole and a core placed inside the drilled hole. The core includes a plurality of anchor bars, a grout, and a grouting pipe. One end of the anchor bar is embedded in the hole In the slurry, the other end of the anchor bar extends in a direction away from the slurry, and one end of the grouting pipe is embedded in the slurry, and the slurry has a bottom close to the bottom of the drilled hole, The grouting pipe penetrates the bottom of the slurry, the other end of the grouting pipe extends in a direction away from the slurry, and one end of the anchor bar and one end of the grouting pipe are respectively connected to the grouting The body is in a fixed arrangement.
The prefabricated prestressed anchor rod structure according to claim 1, wherein a plurality of the anchor ribs are arranged at a circumferential interval along the grouting pipe.
The prefabricated prestressed anchor rod structure according to claim 2, wherein the distance between adjacent anchor bars is 10-60 mm, and the diameter of the anchor bars is 12-80 mm.
The prefabricated prestressed anchor rod structure according to any one of claims 1 to 3, wherein the anchor bar includes an anchor section and a free section, the anchor section is in the slurry, and the free section is provided There is an isolation sleeve, the isolation sleeve surrounds the free section, and the inner end of the isolation sleeve is embedded in the slurry.
The prefabricated prestressed anchor rod structure according to claim 4, wherein the inner end of the isolation sleeve is embedded in the slurry in a range of 200-300 mm.
The prefabricated prestressed anchor rod structure according to any one of claims 1 to 3, wherein one end of the grouting pipe is embedded in the middle of the slurry, and each of the anchor bars is along the grouting pipe. The circumference is arranged around intervals.
The prefabricated prestressed anchor rod structure according to any one of claims 1 to 3, wherein the prefabricated prestressed anchor rod structure includes a template member, and each of the anchor bars and the grouting pipe is lashed Relatively fixed, one end of each anchor bar and one end of the grouting pipe are respectively placed in the template member, grouted and vibrated to form the core; the diameter of the core is in the range of 60-150 mm.
The prefabricated prestressed anchor rod structure according to any one of claims 1-3, wherein the outer surface of the slurry is provided with transverse ribs, and the transverse ribs are arranged spirally around the slurry. The outer surface.
9. The prefabricated prestressed anchor structure of claim 8, wherein the transverse ribs are arranged in an inclined shape.
The prefabricated prestressed anchor rod structure according to any one of claims 1-3, wherein the core includes a steel mesh, the steel mesh is in the slurry, and the steel mesh surrounds They are combined to form an enclosed space, and a plurality of the anchor bars and the grouting pipe are all located in the enclosed space.