Basalt fiber pre-stressed anchor cable system and anchoring method thereof
Technical Field
The invention relates to an anchoring device, in particular to a basalt fiber pre-stressed anchor cable system and an anchoring method thereof.
Background
The prestressed anchor cable technology has been proven by numerous engineering applications as one of the reinforcement measures for limiting deformation, improving the stress state of the rock-soil mass and improving the stability of the rock-soil mass in the anchoring engineering due to simple structure, economy and high efficiency. In recent years, the prestressed anchor cable technology has high practicability in the wide application in various fields such as tunnel slopes, deep foundation pits, reservoir dam foundations, mine chambers and the like.
The prestressed anchor cable is used as an active reinforcing technology commonly used in slope, surrounding rock chamber and tunnel reinforcing engineering. And the traditional prestressed tension cables such as the common parallel steel wire bundles, the steel strands and the like are easy to generate various diseases such as corrosion failure, creep relaxation and the like due to material reasons, and the anchor cable support system is easy to suddenly fail due to various diseases. In order to ensure the safe operation of the traditional prestressed anchor cable, the operation and maintenance difficulty of an anchoring system is higher, and the cost is higher. Therefore, a new prestressed anchorage cable system is needed to more reasonably anchor the engineering.
Disclosure of Invention
The purpose of the invention is as follows: in order to overcome the defects of the prior art, the basalt fiber prestressed anchor cable system provided by the invention effectively solves the problem of sudden instability of the traditional prestressed anchor cable in an underground water-rich area, avoids the problem of corrosion of steel in an underground water-rich environment, improves the creep relaxation phenomenon of the traditional anchor cable system in a long-term operation stage, improves the flexible support efficiency of the anchor cable, prolongs the service life of the traditional anchor cable, and improves the reliability of the prestressed anchor cable system.
Another object of the present invention is to provide an anchoring method of the above prestressed anchorage cable system.
The technical scheme is as follows: a basalt fiber prestressed anchor cable system is characterized by comprising a prestressed working anchor system, a tail end anchor, a basalt fiber anchor cable and a buncher positioned between the prestressed working anchor system and the tail end anchor; the prestressed working anchorage device system comprises a working anchor disc and a limiting device positioned on the outer side of the working anchor disc; the tail end anchor is provided with a sawtooth-shaped outer side surface and a plurality of cable hole channels, and the cable hole channels extend on a straight line pointing to the direction of the working anchor disk and penetrate through the tail end anchor; the basalt fiber anchor cable is provided with a basalt fiber cable strand, the basalt fiber cable strand penetrates through the working anchor disc, the buncher and one cable channel of the tail end anchor device, the other cable channel of the tail end anchor device, the buncher and the working anchor disc at least once from the outer side of the working anchor disc, the end of the basalt fiber cable strand is fixed on the outer side of the working anchor disc through the limiting device, and the basalt fiber cable strand is woven and combined into one strand on the outer side of the limiting device.
In one embodiment, the basalt fiber cable rope has a plurality of basalt fiber strands, and each basalt fiber strand is threaded back and forth once along the path.
Two ends of each basalt fiber strand are woven into one strand outside the limiting device to form a woven part of the basalt fiber strand, and the woven parts of two adjacent basalt fiber strands are crossed with each other. The cable strands are integrally formed and simultaneously mutually limited through weaving so as to improve the cable strand relaxation phenomenon.
And two ends of each basalt fiber cable strand are respectively woven with one end of each of two adjacent basalt fiber cable strands and are sequentially connected in series to form a whole outside the limiting device. So that the basalt fiber cable strands are correspondingly connected to form limiting.
As another embodiment, the basalt fiber cable rope has only one basalt fiber strand, and the basalt fiber strand is threaded back and forth along the path a plurality of times until all cable ducts are filled.
Setting the number of the tail end anchors according to different prestress requirements; arranging a tail end anchor for a prestressed anchor cable with a concentrated end anchorage class less than or equal to 200 KN; at least two tail end anchors are arranged for the prestressed anchor cables with concentrated end anchors of which the number is more than or equal to 600KN and the prestressed anchor cables with enlarged ends.
Each part of the prestressed working anchorage device system is made of basalt fibers and a resin matrix and/or made of metal materials coated with the basalt fibers and the resin matrix; the tail end anchor is made of basalt fibers and a resin matrix.
Corresponding to the basalt fiber pre-stressed anchor cable system, the anchoring method provided by the invention adopts the technical scheme that:
when only one basalt fiber cable strand is arranged in the basalt fiber anchor cable, the basalt fiber cable strand is penetrated back and forth along the path for multiple times until all cable duct holes are filled; applying prestress on the outer side of the working anchor disc in a single-strand unidirectional tensioning mode, anchoring by using a limiting device when the tensioning reaches a prestress design value, and weaving one strand on the outer side of the limiting device;
when a plurality of basalt fiber cable strands are arranged in the basalt fiber anchor cable, each basalt fiber cable strand is penetrated once along the path; two ends of each basalt fiber cable strand sequentially penetrate through a limiting device, a penetrating jack and a tool anchor at the outer side of a working anchor plate and then are woven in a crossed mode, then the penetrating jack is adopted to apply prestress to each basalt fiber cable strand, the prestress reaches a design value through tensioning and super-tensioning, after the limiting device is used for fixing, the penetrating jack and the tool anchor are removed, and the ends of the basalt fiber cable strands are woven into one strand.
And after the basalt fiber cable strand is penetrated, grouting is carried out on the anchoring section in a grouting mode according to the form of the tail end anchor.
When the tail end anchor needs to center the support, primary grouting is adopted; when the tail end anchor can be self-centered, secondary pressure grouting is adopted; when the concrete strength of the anchoring section reaches 80% of the designed strength, tensioning the basalt fiber cable strand, then injecting fillers into the non-anchoring section, applying prestress according to the design after plugging is finished, and integrally sealing the prestress working anchorage device system after plugging is finished.
Has the advantages that: this basalt fiber prestressed anchorage cable system replaces traditional steel wire bundle or steel strand through setting up basalt fiber anchor rope, effectively solves the problem of the sudden unstability of traditional prestressed anchorage cable in the abundant area of groundwater, has avoided the steel corrosion under the rich water environment in the underground, has improved the creep relaxation phenomenon of the long-term operation stage of traditional anchor cable system, has promoted anchor cable flexible support efficiency, has prolonged the life of traditional anchor cable, has promoted prestressed anchorage cable system's reliability. The anchoring device with the sawtooth-shaped outer surface is arranged on the anchoring section to be matched with the basalt fiber anchor cable, so that the mechanical engagement force of anchoring slurry and the anchor cable is increased, the expanded end of the anchoring section is formed, the integrity of the basalt fiber anchor cable system is improved, the ultimate bearing capacity of the anchor cable system can be effectively improved, and the probability of creep deformation of the anchor cable system is reduced; the anchor cable end heads are connected into a whole outside the working anchor in a weaving mode so as to reduce the probability of looseness of the basalt fiber anchor cable, effectively reduce the anchor cable looseness in the long-term use process, improve the overall stability of the anchor cable system and prolong the service life of the anchor cable system. The anchoring method provides different anchoring modes aiming at different prestress requirements, and is easy for field construction.
Drawings
FIG. 1 is a schematic structural view of a basalt fiber prestressed anchorage cable system of the present invention;
FIG. 2 is a perspective schematic view of the caudal anchor of the present invention;
FIG. 3 is a schematic cross-sectional view of the trailing anchor of FIG. 2 taken along the line A-A;
fig. 4 is a schematic diagram of two weaving modes of the basalt fiber rope strand at the outer ends of the working anchor and the conical plug, wherein fig. 4a is a schematic diagram of a cross weaving mode, and fig. 4b is a schematic diagram of a parallel weaving mode.
Detailed Description
To facilitate an understanding of the invention, the invention will now be described more fully with reference to the accompanying drawings. Preferred embodiments of the present invention are shown in the drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.
It will be understood that when an element is referred to as being "secured to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In addition, the term "and/or" herein is only one kind of association relationship describing an associated object, and means that there may be three kinds of relationships, for example, a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention herein is for the purpose of describing particular embodiments only, and is for the purpose of illustration only, such as "inner", "outer", "left", "right", and the like, and is not intended to be limiting of the invention.
As shown in fig. 1 to 4, a basalt fiber pre-stressed anchor cable system comprises a pre-stressed working anchor system 1, a tail end anchor 2, a basalt fiber anchor cable 3 and a buncher 4.
The prestressed work anchorage system 1 comprises a conical plug, a work anchor disc 11, a clamping piece, an anchor backing plate, a spiral rib and the like which are made of basalt fibers and a resin matrix, and the basalt fiber prestressed anchorage system with higher requirement on the prestress design value can be designed into a metal anchorage coated with the basalt fibers and the resin matrix, and of course, each part of the prestressed work anchorage system 1 can be manufactured in a mixed mode or made of other FPR materials.
The tail anchor 2 is a columnar structure with a sawtooth-shaped outer surface, which is made of basalt fibers and a resin matrix, and mainly has the functions of increasing mechanical engagement force, improving limit bearing capacity and increasing safe storage of system anchoring bearing capacity. The tail anchor 2 can be used singly or in series or in parallel.
The basalt fiber cable strand 31 of the basalt fiber anchor cable 3 is formed by weaving or bundling and thermoplastic molding basalt fiber tows, and has good flexibility and tensile property.
Specifically, during construction, after the tail end anchor 2 is reeved, the tail end anchor is placed at the designed position of the anchoring section, then grouting is performed on the anchoring section, and the grouting mode is selected according to the form of the tail end anchor 2. If the tail anchor 2 is small and the support needs to be centred, a primary grouting can be used, and if the tail anchor 2 is self-centring, a secondary grouting is considered necessary. When the concrete strength of the anchoring section reaches 80% of the designed strength, the basalt fiber cable strand 31 is tensioned, then filler is injected into the non-anchoring section, after plugging is completed, prestress is applied according to the design, and after plugging is completed, the prestress working anchorage device system 1 is integrally sealed.
The specific anchoring method can be divided into two modes aiming at different prestress requirements, and for the medium-low prestress anchor cable, only one basalt fiber cable strand 31 can be arranged to form the basalt fiber anchor cable 3; for the medium-high prestressed anchor cable and the end-expanded prestressed anchor cable, a plurality of basalt fiber strands 31 are required to be arranged to form the basalt fiber anchor cable 3, and after the number is determined, the number of cable channels 21 of the tail end anchor 2 is twice as large as the number of the basalt fiber strands 31 (when the tail end anchors 2 are connected in series, the cable channels 21 connected in series are regarded as one cable channel).
When only one basalt fiber cable strand 31 is arranged in the basalt fiber anchor cable 3, the basalt fiber cable strand 31 is penetrated and arranged from the outer side of the working anchor disc 11 along the path of the working anchor disc 11, the buncher 4, one cable duct 21 of the tail end anchor 2, the other cable duct 21 of the tail end anchor 2, the buncher 4 and the working anchor disc 11 for multiple times back and forth until all the cable ducts 21 are filled; and applying prestress at the outer end of the working anchor disc 11 in a single-strand unidirectional tensioning mode, anchoring by using a conical plug when the tensioning reaches a prestress design value, and weaving a strand at the outer side of the conical plug.
When the number of the basalt fiber strands 31 in the basalt fiber anchor cable 3 is half of the number of the cable hole channels 21, each basalt fiber strand 31 is penetrated and arranged once along the path of the working anchor disk 11, the buncher 4, one cable hole channel 21 of the tail end anchor 2, the other cable hole channel 21 of the tail end anchor 2, the buncher 4 and the working anchor disk 11 from the outer side of the working anchor disk 11; two ends of each basalt fiber cable strand 31 sequentially penetrate through a conical plug, a piercing jack and a tool anchor at the outer end of the working anchor plate 11 and then are woven in a cross mode, then the piercing jack is used for applying prestress to each basalt fiber cable strand 31, the prestress reaches a design value through tensioning and over-tensioning, after the conical plug is used for anchoring, the piercing jack and the tool anchor are removed, and the ends of the basalt fiber cable strands 31 are woven into one strand outside the conical plug.
For the second anchoring means described above, two different knitting means may be used. In the cross braiding anchoring mode, as shown in fig. 4a, both ends of each basalt fiber strand 31 are braided to form braided parts on the outer sides of the working anchor plate 11 and the conical plug, and the braiding of two adjacent basalt fiber strands 31 are crossed with each other. The cable strands are integrally formed and simultaneously mutually limited through weaving so as to improve the cable strand relaxation phenomenon. And in combination with the method 4b in fig. 4, the parallel weaving anchoring mode is that two ends of each basalt fiber strand 31 and one end of each adjacent basalt fiber strand 31 are respectively woven and sequentially connected in series at the outer side of the working anchor disk 11 and the conical plug so as to form all the basalt fiber strands 31 into a whole. So that the basalt fiber cable strands are correspondingly connected to form limiting.
The application of the basalt fiber pre-stressed anchor cable system is beneficial to popularization of application of basalt fiber products, the system has higher durability, can prolong the service life of anchoring engineering, and is suitable for various anchoring engineering of traffic engineering.