CN217400934U - Combined anchor rod with prestressed rod core - Google Patents
Combined anchor rod with prestressed rod core Download PDFInfo
- Publication number
- CN217400934U CN217400934U CN202121236748.3U CN202121236748U CN217400934U CN 217400934 U CN217400934 U CN 217400934U CN 202121236748 U CN202121236748 U CN 202121236748U CN 217400934 U CN217400934 U CN 217400934U
- Authority
- CN
- China
- Prior art keywords
- prestressed
- core
- rod
- concrete
- prestressed concrete
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Piles And Underground Anchors (AREA)
Abstract
The utility model discloses a combined anchor rod with a prestressed rod core, which consists of an inner prestressed concrete rod core and an outer cast-in-place anchoring slurry body, wherein a prestressed rib is arranged in the concrete rod core and is prefabricated by a pretensioning method; the anchoring slurry wraps the prestressed concrete pole core, and the cast-in-place anchoring slurry is formed after the prestressed concrete pole core is placed in a pile hole and is subjected to primary grouting or twice grouting solidification. The utility model discloses a combination stock need not on-spot stretch-draw locking prestressing force, can guarantee prestressing force pole core quality, can shorten the site operation cycle again greatly, can replace current prestressing force and ordinary non-prestressed anchorage pole.
Description
Technical Field
The utility model relates to a construction field of stock, concretely relates to take combination stock of prestressing force rod core.
Background
In areas with abundant underground water, the problem of basement anti-floating is common. The anchor rod is an effective measure for resisting floating of the underground structure of the building engineering, one end of the anchor rod is connected with an engineering structure, and the other end of the anchor rod extends into the stratum and can transfer the tension to the stratum. In addition, the anchor rod is also used for main body reinforcement of slopes, tunnels and dams and wind overturn resistance of high-rise buildings. The anchor rod is widely applied and has a mature standardized system and construction process. The related national and industrial standards include technical specification of supporting engineering of rock-soil anchor rods and sprayed concrete (GB 50086-2015), technical specification of rock-soil anchor rods (cables), and special sections of technical specification of foundation pit supporting and technical standard of anti-floating in building engineering relate to anchor rods.
The anchor rods are classified into grouting type and mechanical type prestressed anchor rods, tension type and pressure type prestressed anchor rods, load dispersion type anchor rods, full-length bonding type anchor rods, resin roll and rapid-hardening cement roll anchor rods, hollow grouting anchor rods, friction type anchor rods and the like, and the common characteristic of the anchor rods is that the anchor rods are formed in a hole and cast in situ.
In order to facilitate construction, the anti-floating anchor rod of the underground engineering usually adopts a non-prestressed anchor rod, and the conventional construction process is as follows: anchor rod making → drilling machine in place hole forming → emptying → anchor rod mounting → pressure grouting → finishing. The anchor rod has the remarkable advantages of high bearing capacity, reliable quality, simple process and low comprehensive cost.
Due to the characteristics of small diameter and relatively large tensile bearing capacity of the anchor rod, the non-prestressed anchor rod is easy to have durability problem due to cracks. Particularly, in a site where soil and water corrode the steel bars, cracks are generated in the anchor rods to cause the steel bars to rust and expand, so that the integral anti-floating failure is caused. According to the requirements of the technical Standard for anti-floating of constructional engineering (JGJ476-2019), the engineering with the anti-floating design grade of the first grade is designed according to the condition that the anchor rod anchoring slurry does not generate tensile stress; the project with the anti-floating design level of B level is designed according to no crack, and a prestressed anchor rod is required to be adopted.
The prestressed anchor rod can effectively control the generation of cracks and improve the durability of the anchor rod, but the prestressed anchor rod can be tensioned after the basement bottom plate is poured, and the method is shown in figure 1. The bottom plate is tensioned, the construction period is long, and the pore reserved in the bottom plate is easy to cause water leakage of the basement.
SUMMERY OF THE UTILITY MODEL
Be different from present all concrete anchor rods all in the characteristics of cast in situ, the utility model provides a take combination anchor rod of prestressing force core, this combination anchor rod includes prefabricated prestressing force concrete core and cast-in-place anchor slurry, keeps somewhere the slip casting pipe in advance at the core part, or at finished product core outside ligature slip casting pipe for the secondary slip casting to improve the bonding property between anchor rod and the pore wall, thereby improve anchor rod resistance to plucking ability. The anchor rod can solve the problem that the pore channel of the existing prestressed anchor rod must be reserved in the bottom plate, so that water leakage of a basement is caused.
The purpose of the utility model is realized through the following technical scheme:
a modular anchor with a prestressed core, the modular anchor comprising:
the prestressed concrete pole core is positioned on the inner side, and prestressed tendons are arranged inside the prestressed concrete pole core and are prefabricated by a pretensioning method;
the cast-in-place anchoring slurry body is located on the outer side, wraps the prestressed concrete pole core, and is formed after the prestressed concrete pole core is placed in a pile hole and is subjected to one-time grouting or two-time grouting solidification through the anchoring slurry body.
Furthermore, a rod core positioning device and a grouting pipe preformed groove are arranged on the outer peripheral surface of the prestressed concrete rod core.
Furthermore, the number of the prestressed tendons in the prestressed concrete core is 3.
Further, the radius R1 of the prestressed concrete pole core is 50-75 mm, and the thickness of the anchoring slurry is 30-60 mm.
Further, the anchoring slurry is cement slurry.
Furthermore, in order to enhance the bonding performance between the prestressed concrete pole core and the cast-in-place anchoring slurry, bamboo-like or point-like protrusions or recesses are arranged on the peripheral surface of the prestressed concrete pole core.
Furthermore, the core of the prestressed concrete pole is in a frustum shape with a small upper part and a big lower part.
The beneficial effects of the utility model are as follows:
(1) in a corrosive field, a common anchor rod usually cracks to reduce the durability of the anchor rod; under the long-term action of the underground water level fluctuation and the dry-wet alternative environment, the tiny cracks can be continuously enlarged, so that the reinforcing steel bars inside the components are corroded, the strength is reduced, and serious potential safety hazards are caused. In contrast, new industry specifications have proposed mandatory requirements for the use of prestressed anchors for projects of design class a and class one; for the anchor rod with the design grade of grade C, the consumption of the reinforcing steel bar can be saved by more than 60-70%. The utility model discloses a combination stock adopts pretensioning method prestressing force technology, to the stock body prestressing force, and the cracked requirement does not appear in can satisfying the standard of the pole core of combination stock, can effectively improve the durability and the economic nature of anti-floating anchor.
(2) At present, the conventional prestressed anchor rod can be tensioned after the basement bottom plate is poured, the construction process is complex, and the construction period is greatly influenced. The method is characterized in that all existing concrete anchor rods are cast in situ, the production of the prefabricated rod core is carried out in a factory through an industrial pretensioning method prefabrication process, the prefabricated rod core is placed down and installed in a construction site, anchoring slurry is poured to form a combined anchor rod, the assembly type concept and method of the existing upper structure are successfully applied to the field of anti-floating anchor rods, and prefabricated components and assembly type methods are made in the field of anti-floating of foundation engineering. Compared with non-prestressed anchors and conventional slow-bonding prestressed anchors, the novel method can ensure the quality of the prestressed anchor core, greatly shorten the field construction period and reduce the overall cost.
Drawings
FIG. 1 is a construction view of a prestressed anchor in the prior art;
fig. 2 is a schematic view of the combined anchor rod of the present invention;
FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;
fig. 4 is a schematic cross-sectional view of a modular anchor with a core positioning device;
fig. 5 is a schematic view of a composite anchor rod when the core is frustum-shaped;
in the figure, a prestressed concrete rod core 1, cast-in-place anchoring slurry 2, a bottom plate 3, a grouting pipe 4, a rod core positioning device 5, prestressed tendons 101, rod core concrete 102, a grouting pipe preformed groove 103 and point-shaped bulges 104 are arranged.
Detailed Description
The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments, and the objects and effects of the present invention will become more apparent, and it should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.
The utility model discloses a take combination stock of prestressing force rod core has the innovation of three aspect:
(1) traditional prestressing force anti-floating anchor is whole at the cast in situ, the utility model discloses a combination stock that combination anchor rod combined together for mill's prefabrication and cast in situ.
(2) The tradition stock only is non-prestressing force and two kinds of ways of whole prestressing force, the utility model discloses a combination stock, its prefabricated core of rod are the prestressing force component, and the anchor slurry of on-the-spot pouring is non-prestressing force component.
(3) The traditional prestressed anti-floating anchor rod must be tensioned on the surface of the basement bottom plate, and cannot form a complete stress system. The novel anchor rod only establishes prestress under the bottom plate, a self-balancing system is formed under the condition that no bottom plate exists, and the novel anchor rod has better safety under the subsequent basement construction condition.
As shown in fig. 2, the utility model discloses a take combination stock of prestressing force rod core, include:
the prestressed concrete pole core 1 is positioned on the inner side, the prestressed concrete pole core 1 is prefabricated by a pretensioning method, and a prestressed rib 101 is arranged inside the prestressed concrete pole core 1;
the cast-in-place anchor slurry 2 is located on the outer side, the cast-in-place anchor slurry 2 wraps the prestressed concrete pole core 1, and the cast-in-place anchor slurry 2 is formed by placing the prestressed concrete pole core 1 in a pile hole and performing one-time grouting solidification. When the anchoring slurry is cement slurry, the anchoring slurry is formed after primary grouting solidification, but when the anchoring slurry is mixed mortar, the slurry can shrink greatly after the primary grouting solidification, so that cracks appear in the anchoring slurry, secondary grouting is needed at the moment, and the whole anchoring slurry is obtained after the secondary grouting solidification.
As shown in fig. 3, because the diameter of the anchor rod is smaller, the radius R1 of the prestressed concrete rod core 1 is 50-75 mm, the thickness of the cast-in-place anchoring slurry 2 is 30-60 mm, and a prestressed tendon can be adopted in the prestressed concrete rod core 1; considering the factors of transportation and construction deviation, three prestressed ribs may be set inside the rod core to strengthen the bending resistance of the rod body. And the prestressed concrete pole core 1 can be selected from prestressed reinforcement or steel strand wires. The cast-in-situ anchoring slurry 2 is cement slurry.
As shown in fig. 4, in order to enhance the adhesion between the prestressed concrete pole core 1 and the cast-in-place anchoring slurry 2, bamboo-like or dot-like protrusions 104 may be provided on the outer circumferential surface of the prestressed concrete pole core 1. The rod body is generally round, and can also adopt a square, oval or other cross sections. Meanwhile, in order to avoid the offset in the process of placing the pile hole by the prestressed concrete pole core, preferably, the prestressed concrete pole core 1 is provided with a pole core positioning device 5 which can be a 30x30xh protrusion (h is the distance from the pole core to the hole wall, namely-0.5 cm), 3 in the circumferential direction and 2 in the longitudinal direction. Meanwhile, the prestressed concrete pole core 1 is provided with a grouting pipe preformed groove 103 for binding a grouting pipe before the pole core is lowered into a pile hole. The number of the grouting pipes is 2, and primary grouting and secondary grouting are respectively carried out.
As shown in fig. 5, the prestressed concrete core is preferably in the shape of a frustum with a small top and a large bottom, and at this time, under the action of a tensile force, the prestressed concrete pile core 1 can extrude the cast-in-situ anchoring slurry 2 and the hole wall, so that the combined anchor rod has better bearing capacity. And because of adopting the factory prefabrication production, the rod core is easy to realize, but the prior cast-in-place anchor rod cannot realize.
To avoid offsetting the core placement process, the rods are preferably provided with a three-way positioning means, which may be a 30x30xh protrusion (h is the distance from the core to the wall of the hole-0.5 cm), 3 in the circumferential direction and 2 in the longitudinal direction. Meanwhile, the rod core is provided with a grouting pipe reserved groove for binding the grouting pipe before the rod core is placed in the cavity. The number of the grouting pipes is 2, and primary grouting and secondary grouting are respectively carried out.
The utility model discloses a take construction method of combination stock of prestressing force rod core, including following step:
s1: prefabricating a prestressed concrete pole core 1 by a pretensioning method in a factory: the diameter of the prefabricated rod core is controlled to be 100-150 mm; firstly, stretching steel bars on a pedestal, then pouring a concrete rod core, reserving a grouting pipeline in the rod core, and releasing a stretching end after the strength reaches a design value to enable the rod core to form prestress; meanwhile, one section of steel bar is reserved on one side of the rod core for anchoring, and the steel bar on the other side is cut off along the end part of the rod core;
s2: drilling holes by a drilling machine on a construction site;
s3: cleaning holes, binding grouting pipes 4, then lowering the prefabricated prestressed concrete pole core 1, and ensuring that the prestressed concrete pole core 1 and the pile holes are coaxial;
s4: performing primary grouting around the prestressed concrete pole core 1, and performing secondary grouting after the primary grouting is solidified and contracted to obtain cast-in-place anchoring slurry 2;
s5: and (4) anchoring the prestressed tendons 101 reserved in the rod cores into the bottom plate 3, and pouring the bottom plate 3 to complete the basement construction.
Be different from conventional prestressed component, because the stock diameter is generally at 150 ~ 240mm, and length is at 4m ~ 15m, considers peripheral anchor slurry, the utility model relates to a prestressed concrete pole core 1 diameter is littleer, carries out the application of prestressing force to it and must guarantee the positioning accuracy of prestressing tendons, avoids the deviation to arouse additional moment of flexure, also can embody the advantage of factory prefabrication production more.
Due to small cross-section of the core, its degree of prestressThe elastic compression deformation and the later shrinkage creep of the prestressed component are obviously higher than those of the common prestressed component, so that the prestress loss is further increased. At present, the prestress loss of the pretensioned axial compression member is shown in the first four items in table 1 according to the current concrete structure design specifications. The table prestress loss does not include the loss caused by the compression of the rod body due to the release of the tension steel bar, and the prestress loss sigma is supplemented on the basis of the existing specification through analysis in view of the characteristic that the section of the rod core is small S 。
TABLE 1 analysis of loss of prestress
The advantages of the combined anchor rod of the present invention are demonstrated and the prestress loss is calculated in the following by an embodiment.
Prestress loss analysis was performed on a certain 8m combination uplift pile, and the calculation results are shown in table 2. Wherein the strength grade of the concrete is C40, and the diameter of the pile core is 150 mm; the diameter of the prestressed tendons is 12.6mm, the number of the prestressed tendons is 3, and the tension control stress is 994 Mpa.
TABLE 2 analysis of prestress loss of certain 15m combined uplift pile
| Type of loss of prestress | Calculated result/(N/mm) 2 ) | Remarks to note |
| σ l1 | 75 | Take a to 3mm |
| σ l3 | 40 | Taking delta t as 20 DEG C |
| σ l4 | 29.8 | — |
| σ s | 164.0 | — |
| σ l5 | 99.7 | — |
The examples show that the elastic shrinkage deformation loss is 24.4% of the total loss. In order to reduce the prestress loss, it is preferable to add an appropriate amount of expanding agent to the rod body. The compressive stress in the rod body is ensured through later-stage expansion of the concrete, and meanwhile, the pressure between the combined pile and the rock soil can be improved, so that the uplift bearing capacity of the combined anchor rod is enhanced. Compared with a non-prestressed anchor rod, the steel consumption is 20-30% of the original steel consumption.
It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention and is not intended to limit the invention, and although the present invention has been described in detail with reference to the foregoing examples, it will be apparent to those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof. All modifications and equivalents made within the spirit and principles of the invention are intended to be included within the scope of the invention.
Claims (7)
1. The utility model provides a take combination stock of prestressing force rod core which characterized in that, this combination stock is located the pile hole, the combination stock includes:
the prestressed concrete pole core comprises a plurality of prestressed tendons arranged inside the prestressed concrete pole core and pole core concrete wrapping the prestressed tendons;
and the cast-in-place anchoring slurry body is positioned on the outer side and wraps the rod core concrete.
2. A modular anchor rod with a prestressed rod core according to claim 1, characterized in that the prestressed concrete rod core is provided with a rod core positioning means and a grouting pipe pre-groove on its outer circumferential surface.
3. A composite anchor rod with a prestressed rod core according to claim 1, characterized by that the prestressed tendons in the interior of the prestressed concrete rod core are 3.
4. A modular anchor bolt with a prestressed core, according to claim 1, in which the radius R1 of the prestressed concrete core is 50-75 mm, and the thickness of the anchoring slurry is 30-60 mm.
5. A modular anchor rod with a prestressed rod core according to claim 1, characterised in that the anchoring grout is a cement grout.
6. A modular anchor rod with a prestressed core as claimed in claim 1, wherein the prestressed core is provided with bamboo-like or dotted protrusions or recesses on its outer circumferential surface in order to enhance the adhesion between the prestressed concrete core and the cast-in-place anchoring slurry.
7. A composite anchor rod with a prestressed rod core according to claim 1, characterized in that said prestressed concrete rod core is in the form of a frustum whose upper part is small and lower part is large.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121236748.3U CN217400934U (en) | 2021-06-03 | 2021-06-03 | Combined anchor rod with prestressed rod core |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121236748.3U CN217400934U (en) | 2021-06-03 | 2021-06-03 | Combined anchor rod with prestressed rod core |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217400934U true CN217400934U (en) | 2022-09-09 |
Family
ID=83131848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202121236748.3U Active CN217400934U (en) | 2021-06-03 | 2021-06-03 | Combined anchor rod with prestressed rod core |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217400934U (en) |
-
2021
- 2021-06-03 CN CN202121236748.3U patent/CN217400934U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11293183B2 (en) | Precast column base joint and construction method therefor | |
| CN108301561B (en) | Connection structure of assembled steel pipe concrete column shaft | |
| CN113217059A (en) | Combined anchor rod with prestressed rod core | |
| CN102383418A (en) | Anti-seismic prefabricated concrete solid square pile and production method thereof | |
| CN104929117B (en) | Construction method of concrete pole body composite anchor rod | |
| CN108678218B (en) | Assembly type concrete shear wall based on multipurpose thin-wall steel pipe and construction method thereof | |
| CN109487681B (en) | Construction method of abrasion-resistant ultrahigh-performance concrete restrained segment spliced pier | |
| CN201411899Y (en) | Template structure for tower-silo reinforcement construction | |
| CN217400934U (en) | Combined anchor rod with prestressed rod core | |
| CN104264659A (en) | Prefabricated hollow uplift pile and preparation method thereof | |
| CN108265744A (en) | Connecting structure of PHC pipe pile foundation pile and bearing platform of overhead transmission line | |
| RU172472U1 (en) | OVERLAP JOINT CONNECTION OF PIPE CONCRETE COLUMN | |
| CN115772848A (en) | Single-layer reinforcement hollow prefabricated pier with built-in metal corrugated pipe | |
| CN108103925B (en) | Assembled hollow steel tube constraint reinforced concrete column short pier | |
| CN108086136B (en) | Assembled solid steel pipe constraint reinforced concrete column short pier | |
| CN213897088U (en) | PSB finish rolling screw-thread steel prestressed concrete fender pile structure | |
| CN114277786A (en) | High-strength concrete bearing body, pressure type anti-floating pile and construction method | |
| CN110656786B (en) | Prestressed steel-concrete combined pile underpinning node and manufacturing method thereof | |
| CN114263093A (en) | Fully-prefabricated assembled bridge and construction method | |
| CN113463626A (en) | Anti-pulling combined pile with built-in prestressed pile core | |
| CN202247861U (en) | Anti-seismic prefabricated concrete solid square pile | |
| CN201826439U (en) | Assembled self-compaction steel tube concrete combined structure | |
| CN111648359A (en) | Construction method of anchor rod pile | |
| CN215406042U (en) | Prefabricated prestressed concrete hollow anchor rod | |
| CN221345569U (en) | Miniature extrusion-expansion anchor rod |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |