CN112726598A - Full-bonding type prestressed steel anchor pipe cable structure and construction method thereof - Google Patents

Full-bonding type prestressed steel anchor pipe cable structure and construction method thereof Download PDF

Info

Publication number
CN112726598A
CN112726598A CN202011641215.3A CN202011641215A CN112726598A CN 112726598 A CN112726598 A CN 112726598A CN 202011641215 A CN202011641215 A CN 202011641215A CN 112726598 A CN112726598 A CN 112726598A
Authority
CN
China
Prior art keywords
pipe
grouting
steel anchor
steel
anchor pipe
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.)
Pending
Application number
CN202011641215.3A
Other languages
Chinese (zh)
Inventor
张玉芳
马兴伟
万军利
刘睿迪
周文皎
樊旭
徐勇
张彩亮
符涛
杨亮
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Railway Engineering Research Institute of CARS
Original Assignee
Railway Engineering Research Institute of CARS
Yunnan Construction and Investment Holding Group Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Railway Engineering Research Institute of CARS, Yunnan Construction and Investment Holding Group Co Ltd filed Critical Railway Engineering Research Institute of CARS
Priority to CN202011641215.3A priority Critical patent/CN112726598A/en
Publication of CN112726598A publication Critical patent/CN112726598A/en
Pending legal-status Critical Current

Links

Classifications

    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D5/00Bulkheads, piles, or other structural elements specially adapted to foundation engineering
    • E02D5/74Means for anchoring structural elements or bulkheads
    • EFIXED CONSTRUCTIONS
    • E02HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02DFOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D17/00Excavations; Bordering of excavations; Making embankments
    • E02D17/20Securing of slopes or inclines
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A10/00TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE at coastal zones; at river basins
    • Y02A10/23Dune restoration or creation; Cliff stabilisation

Abstract

The invention discloses a full-bonding type prestressed steel anchor pipe cable structure and a construction method thereof, which combine the advantages of a prestressed steel anchor cable and an accurate control grouting technology, improve the strength of a rock-soil body and the bonding force between the rock-soil body and the steel anchor pipe through accurate control grouting of the steel anchor pipe, change the stress mode of the prestressed steel anchor pipe through the construction prestress at the bottom of the steel anchor pipe by implanting steel strands into the steel anchor pipe, greatly improve the anchoring force, have the advantages of reasonable structure, advanced technology, economy, reasonability, good anticorrosion effect and the like, and are a novel side slope reinforcement technology suitable for side slope anchoring.

Description

Full-bonding type prestressed steel anchor pipe cable structure and construction method thereof
Technical Field
The invention relates to the technical field of slope anchoring engineering, in particular to a full-bonding type prestressed steel anchor pipe cable structure and a construction method thereof.
Background
The slope anchoring engineering is used as a hidden engineering, main materials of steel and concrete are buried in various types of rock-soil bodies, an anchoring section is in a stratum where underground water is relatively developed, hole collapse and hole shrinkage are easy to occur in the drilling process, the installation difficulty of an anchor cable is relatively high, the binding force between the anchoring section and a soil layer is limited, and the anchoring section is in contact with the underground water and a site soil medium for a long time, so that the physical and mechanical properties of the anchoring structure, such as durability, strength and the like, are reduced.
The method aims to improve the stratum anchoring effect and solve the problem of anchor cable installation, not only improves the prior art, but also combines a continuously developed new technology, researches a new combined structure of a grouting steel anchor pipe and a prestressed anchor cable for multiple times, develops a combined reinforcing innovative structure which has the advantages of rapid reinforcement, convenient construction, better solution of high difficulty of anchor cable installation and construction, insufficient anchoring force, weak durability and the like, and is a necessary way for slope emergency rescue and reinforcement engineering.
Disclosure of Invention
The invention aims to mainly solve the problems of high installation and construction difficulty, insufficient anchoring force, poor durability, quick reinforcement, convenience in construction and the like of an anchor cable in the prior art, and provides a full-bonding type prestressed steel anchor pipe cable structure and a construction method thereof.
In order to achieve the purpose, the invention is implemented according to the following technical scheme:
a full-bonding type prestressed steel anchor pipe cable structure comprises a grouting prestressed steel anchor pipe arranged in the bottom of a drill hole, a prestressed steel anchor cable arranged in the grouting prestressed steel anchor pipe, and an outer anchoring end arranged outside the drill hole and connected with the grouting prestressed steel anchor pipe and the prestressed steel anchor cable; the outer anchoring end comprises a concrete beam arranged on the outer side slope of the drilled hole, a wedge-shaped anchor pier fixed on the outer side wall of the concrete beam, a supporting plate fixed on the wedge-shaped anchor pier, a setting nut, a setting anchorage device, a steel retaining cylinder and anchor sealing concrete, the tail ends of the grouting prestressed steel anchor pipe and the prestressed anchor cable sequentially penetrate through the concrete beam, the wedge-shaped anchor pier and the supporting plate, the tail end of the grouting prestressed steel anchor pipe is locked by the setting nut for a tensioning section, the tail end of the prestressed anchor cable is anchored at the rear end of the setting nut by the setting anchorage device, the steel retaining cylinder is fixed on the supporting plate to cover the setting nut and the setting anchorage device, and finally the steel retaining cylinder and the supporting plate.
Furthermore, the grouting prestressed steel anchor pipe comprises a steel anchor pipe, a conical guide head, a centering frame, a primary grouting pipe and a tertiary grouting pipe, wherein the steel anchor pipe is divided into an anchoring section steel anchor pipe and a free section steel anchor pipe, the conical guide head is arranged at the bottom of the anchoring section steel anchor pipe and extends into the bottom of a drill hole, a plurality of grouting holes are formed in the anchoring section steel anchor pipe, the grouting holes are plugged with glass cement, the centering frame is sleeved on the outer side of the wall of the anchoring section steel anchor pipe, the primary grouting pipe is fixed on the outer wall of the steel anchor pipe and extends into the bottom of the drill hole together with the steel anchor pipe for injecting primary grouting into the drill hole, and the tail end of the primary grouting pipe extends out of the drill hole; the free section steel anchor pipe overcoat is equipped with the protecting pipe, form the clearance between sealed and free section steel anchor pipe in protecting pipe bottom and the protecting pipe, the clearance bottom that cubic slip casting pipe front end was fixed between free section steel anchor pipe and protecting pipe is used for pouring into cubic slip casting body in the clearance between free section steel anchor pipe and the protecting pipe into, and cubic slip casting pipe rear end extends outside the drilling.
Furthermore, the prestressed anchor cable comprises a plurality of unbonded steel strands extending into the bottom of the steel anchor pipe and an overhead line ring axially arranged on the inner wall of the steel anchor pipe, the plurality of unbonded steel strands respectively penetrate through a plurality of line passing holes formed in the overhead line ring, and the unbonded steel strands between every two adjacent overhead line rings in the anchor section steel anchor pipe are bound by a stirrup ring.
Further, drilling holes on the upper slope surface of the side slope, wherein the included angle between the downward direction of the drilling holes and the horizontal direction is 20-25 degrees.
Furthermore, a centering frame is arranged on each anchoring section steel anchor pipe every 2.0 m.
Furthermore, one stringing ring is arranged in the steel anchor pipe of the anchoring section at intervals of 1.5-2m, and one stringing ring is arranged in the steel anchor pipe of the free section at intervals of 2-3 m.
Furthermore, the tail end of the steel anchor pipe, namely the tensioning section, is machined with a turning wire, the length of the turning wire is 15cm, the tooth pitch is 3mm, and the tail end of the steel anchor pipe, namely the tensioning section, is in threaded connection with a shaping nut.
Further, the front end of the tertiary grouting pipe is fixed at a position 20cm above the bottom of the protective sleeve.
Furthermore, the number of the unbonded steel stranded wires is three, the unbonded steel stranded wires are coated with steel stranded wire anti-corrosion grease and coated with PE (polyethylene) sleeves, and the PE sleeves and the steel stranded wire anti-corrosion grease are removed from the 10-15 m positions of the tail sections of the unbonded steel stranded wires and then anchored at the rear ends of the sizing nuts by using sizing anchors.
In addition, the invention also provides a construction method of the full-bonding type prestressed steel anchor pipe cable structure, which comprises the following steps:
(1) assembling a grouting prestressed steel anchor pipe;
(2) grouting hole sealing: injecting glass cement into the grouting hole by using a cement gun, checking the sealing condition of the grouting hole after the glass cement is solidified, and performing glue filling and sealing on the grouting hole;
(3) drilling: the drilling process of the drilling comprises the following steps: positioning a hole site, building a drilling machine platform, compounding the hole site, accurately positioning the drilling machine, drilling holes and checking;
(4) extending the assembled grouting prestressed steel anchor pipe into the drill hole;
(5) primary grouting: reversely pressing in the primary grouting body from the bottom of the drill hole to the top through the primary grouting pipe, continuously overflowing the purified mud at the drill hole opening, and timely replenishing the primary grouting body on site if the retraction of the hole opening grout is found after the primary grouting is finished;
(6) secondary grouting: injecting high-pressure secondary splitting grouting bodies into the steel anchor pipes through the steel anchor pipe openings, splitting grouting holes in the steel anchor pipes at the anchoring sections and the primary grouting bodies, diffusing the split grouting holes and the primary grouting bodies to the periphery, filling gaps among the soft stratum and the soil layer of the rock stratum, and improving the anchoring force;
(7) assembling a prestressed anchor cable;
(8) installation of a prestressed anchor cable: after primary grouting is finished and before secondary grouting, inserting a prestressed anchor cable into the steel anchor pipe and extending into the bottom of the steel anchor pipe;
(9) tensioning and locking the steel anchor pipe: when the strength of the primary grouting body and the secondary splitting grouting body reaches the design requirement, tensioning the steel anchor pipe to the designed anchoring force, and locking by adopting a shaping nut;
(10) and (3) third grouting: injecting tertiary grouting body into the gap between the free section steel anchor pipe and the protective sleeve at normal pressure through the tertiary grouting pipe until the gap between the free section steel anchor pipe and the protective sleeve is filled;
(11) tensioning and locking the prestressed anchor cable: after the strength of the free section of the steel anchor pipe reaches the design requirement, tensioning and locking the unbonded steel strand until the designed anchoring force is reached, and locking by adopting a shaping anchorage device;
(12) sealing an anchor: after the prestressed anchor cable is tensioned and locked for one month, and after the anchoring force is stabilized, a steel casing is fixed on the supporting plate to cover the shaping nut and the shaping anchorage, the steel casing is filled with anticorrosive grease, and finally the steel casing and the supporting plate are sealed by anchor sealing concrete.
Compared with the prior art, the invention has the following beneficial effects:
1. improve the anchoring force
Through steel anchor pipe secondary splitting slip casting, to splitting around the drilling, improved the intensity of ground body, strengthened the adhesive force of steel anchor pipe with the ground body, exert prestressing force from steel anchor pipe bottom through the steel strand wires, the effectual anchor section length that has increased integrated configuration, great improvement the anchor power.
2. Solves the problem of high difficulty in mounting the anchor cable
Because prestressed anchorage cable steel strand wires belong to flexible construction, meet hole collapse, shrinkage cavity, the anchor rope installation degree of difficulty is very big, and the steel anchor pipe belongs to rigid construction, simple to operate, through installing the prestressed anchorage cable in the steel pipe after installing the steel anchor pipe earlier, the effectual big problem of the anchor rope installation degree of difficulty that has solved.
3. The durability of the prestressed anchor cable is improved: the unbonded steel strand is implanted into the steel anchor pipe, so that the corrosion of the external environment of the steel anchor pipe to the prestressed anchor cable is effectively avoided, and the durability is good.
In summary, the fully-bonded prestressed steel anchor pipe cable structure disclosed by the invention combines the advantages of a prestressed anchor cable and an accurate grouting control technology, the rock-soil body strength and the bonding force between a rock-soil body and a steel anchor pipe are improved through accurate grouting control of the steel anchor pipe, the stress mode of the prestressed steel anchor pipe is changed by implanting steel strands into the steel anchor pipe through prestress construction at the bottom of the steel anchor pipe, the anchoring force is greatly improved, and the fully-bonded prestressed steel anchor pipe cable structure has the advantages of reasonable structure, advanced technology, economy, reasonability, good anticorrosion effect and the like, and is a novel slope reinforcement technology suitable for slope anchoring.
Drawings
Fig. 1 is a schematic structural view of the fully-bonded prestressed steel anchor pipe cable of the present invention.
Fig. 2 is a sectional view a-a of fig. 1.
Fig. 3 is a sectional view B-B of fig. 1.
Reference numerals: 1. drilling; 2. primary grouting; 3. a steel anchor pipe; 4. the unbonded steel strand is used for the production of the steel strand; 5. a stringing ring; 6. a stirrup ring; 7. a primary grouting pipe; 8. a concrete beam; 9. a support plate; 10. shaping the nut; 11. shaping the anchorage device; 12. anticorrosive grease; 13. a steel casing; 14. sealing and anchoring concrete; 15. a wedge-shaped anchor pier; 16. grouting holes; 17. sheathing a pipe; 18. a gap; 20. a wire passing hole; 21. secondary splitting grouting body; 22. a conical guide head; 23. centering the frame; 24. a connector; 25. a third grouting pipe; D. an outer anchoring end.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. The specific embodiments described herein are merely illustrative of the invention and do not limit the invention.
Example 1
As shown in fig. 1-3, the fully-bonded prestressed steel anchor pipe cable structure of the present embodiment includes a grouting prestressed steel anchor pipe disposed in the bottom of a borehole 1, a prestressed steel anchor cable disposed in the grouting prestressed steel anchor pipe, and an outer anchoring end D disposed outside the borehole 1 and connected to the grouting prestressed steel anchor pipe and the prestressed steel anchor cable; the outer anchoring end D comprises a concrete beam 8 arranged on the outer side slope of the drill hole 1, a wedge-shaped anchoring pier 15 fixed on the outer side wall of the concrete beam 8, a supporting plate 9 fixed on the wedge-shaped anchoring pier 15, a shaping nut 10, a shaping anchorage device 11, a steel casing 13 and anchoring concrete 14, the grouting prestressed steel anchor pipe and the tail end of the prestressed anchor cable sequentially penetrate through the concrete beam 8, the wedge-shaped anchor pier 15 and the support plate 9, the size of the support plate 9 is 20cm multiplied by 2cm, a phi 80mm eyelet is reserved in the middle of each steel base plate to facilitate the grouting prestressed steel anchor pipe to penetrate through, the tail end of the grouting prestressed steel anchor pipe is a tensioning section and is locked by a setting nut 10, the tail end of the prestressed anchor cable is anchored at the rear end of the setting nut 10 by a setting anchorage device 11, a steel casing 13 is fixed on the support plate 9 to cover the setting nut 10 and the setting anchorage device 11, and finally, the steel casing 13 and the support plate 9 are sealed by sealing anchor concrete 14.
Furthermore, the grouting prestressed steel anchor pipe comprises a steel anchor pipe 3, a conical guide head 22, a centering frame 23, a primary grouting pipe 7 and a tertiary grouting pipe 25, wherein the steel anchor pipe 3 is divided into an anchoring section steel anchor pipe and a free section steel anchor pipe, the conical guide head 22 is arranged at the bottom of the anchoring section steel anchor pipe and extends into the bottom of the drill hole 1, a plurality of grouting holes 16 are formed in the anchoring section steel anchor pipe, the grouting holes 16 are blocked by glass cement, the centering frame 23 is sleeved outside the wall of the anchoring section steel anchor pipe, the centering frame 23 is arranged on the anchoring section steel anchor pipe at intervals of 2.0m, and the centering frame has the function of ensuring a certain protective layer thickness between the steel anchor pipe 3 and the drill hole 1 in the pipe lowering process, ensuring that the periphery of the steel anchor pipe 3 is wrapped by grouting body, and improving the corrosion resistance and tensile bearing capacity of the steel anchor pipe 3; the primary grouting pipe 7 can be bound on the outer wall of the steel anchor pipe 3 by using a steel wire and extends into the bottom of the drill hole 1 together with the steel anchor pipe 3 to be used for injecting the primary grouting body 2 into the drill hole 1, and the tail end of the primary grouting pipe 7 extends out of the drill hole 1; the free section steel anchor pipe overcoat is equipped with protecting pipe 17, protecting pipe 17 bottom is sealed and form clearance 18 between free section steel anchor pipe and the protecting pipe 17, tertiary slip casting body is injected into in clearance 18 between free section steel anchor pipe and the protecting pipe to clearance 18 bottom that tertiary slip casting pipe 25 front end was fixed between free section steel anchor pipe and the protecting pipe, and tertiary slip casting pipe 25 rear end extends outside drilling 1. The tail end of the steel anchor pipe 3, namely the tensioning section, is processed with a turning wire, the length of the turning wire is 15cm, the tooth pitch is 3mm, and the tail end of the steel anchor pipe 5, namely the tensioning section, is in threaded connection with the shaping nut 10.
In this embodiment, the prestressed anchorage cable includes a plurality of unbonded steel strands 4 extending into the bottom of the steel anchor pipe and a plurality of stringing rings 5 axially arranged on the inner wall of the steel anchor pipe, specifically, each stringing ring 5 is arranged at an interval of 1.5-2m in the steel anchor pipe at the anchoring section, each stringing ring 5 is arranged at an interval of 2-3m in the steel anchor pipe at the free section, the plurality of unbonded steel strands 4 respectively pass through a plurality of stringing holes 20 formed in the stringing rings 5, and the unbonded steel strands 4 located between every two adjacent stringing rings 5 in the steel anchor pipe at the anchoring section are bound by the stirrup rings 6. Because the unbonded steel stranded wire 4 is of a flexible structure, the wire stringing ring 5 plays a role in smoothing the unbonded steel stranded wire 4 to improve the rigidity of the steel stranded wire 4, and meanwhile, a certain protective layer thickness is designed to ensure that the periphery of the steel stranded wire 4 is wrapped by the grouting body, so that the corrosion resistance and durability of the anchor cable are improved.
In this embodiment, the front end of the tertiary grouting pipe 25 is fixed 20cm above the bottom of the protecting pipe 17, and grouting is performed downwards from the orifice during grouting and then grouting is performed again until the gap 18 between the free-section steel anchor pipe and the protecting pipe 17 is filled with slurry.
In the embodiment, the number of the unbonded steel stranded wires 4 is three, the unbonded steel stranded wires 4 are coated with steel stranded wire anti-corrosion grease and coated with a PE (polyethylene) sleeve, the unbonded steel stranded wires 4 are not directly contacted with the secondary splitting grouting body 21 through the PE sleeve, and the steel stranded wire anti-corrosion grease has the functions of water resistance, rust resistance and friction reduction; in the actual construction process, the PE sleeve and the anti-corrosion grease of the steel strand are removed from the 10m-15m position of the tail section of the unbonded steel strand 4 to provide anchoring force, and then the rear end of the forming nut 10 is anchored by a forming anchorage device 11.
Example 2
The embodiment provides a construction method of a full-bonding type prestressed steel anchor pipe cable structure, which comprises the following steps:
(1) assembling a grouting prestressed steel anchor pipe;
and (3) processing and manufacturing the steel anchor pipe:
the steel anchor pipe 3 generally adopts a seamless steel pipe with the length of 6m and the diameter of 76 multiplied by 6mm, the seamless steel pipe can be lengthened or shortened according to the requirement in the engineering, the seamless steel pipe is connected by adopting a steel pipe with the diameter of 89 multiplied by 6.5mm after being sleeved and then welded, attention is paid to the welding of the steel pipe, a gap is always formed between the two steel pipes, the seamless connection between the steel pipes is realized during the welding, and the test failure caused by the flowing of slurry into the steel pipe during one-time grouting is avoided; the tail end of the steel anchor pipe 3, namely a tensioning section, is provided with a threading, the threading length is 15cm, and the tooth pitch is 3 mm. The length of the steel pipe is 10cm, a secondary grouting hole 16 is formed in the steel anchor pipe 3 at the grouting control position, the diameter of the hole is phi 8mm, and the hole is spirally arranged.
Manufacturing the centering frame 23:
the centering frame of the steel anchor pipe 3 is made and welded by adopting 3 phi 8 smooth steel bars, the 3 steel bars are arranged in an equilateral triangle shape on the cross section, the length of the smooth steel bars is 20cm, and the centering frame is arranged on the steel anchor pipe at intervals of 2.0 m.
(2) Grouting hole sealing: injecting glass cement into the grouting hole 16 by using a cement gun, and checking the sealing condition of the grouting hole after the glass cement is solidified, wherein the sealing of the secondary grouting hole 16 is ensured at the moment, so that the grout of primary grouting is prevented from flowing into the steel anchor pipe 3; the secondary grouting is the grouting in the steel anchor pipe 3, and the secondary cleavage grouting can be realized only by ensuring that the grout can break the sealed grouting hole 16; the glass cement hole sealing is proved to be a reliable and simple hole sealing mode in practice, the glass cement is driven into the secondary grouting hole by a cement gun, the purpose of sealing the secondary grouting hole can be achieved after the glass cement is solidified, and the glass cement is not easy to damage in the pipe discharging process; meanwhile, the glass cement has low strength and is very easy to break during secondary grouting. The glass cement sealing hole needs attention: the volume of the glass shrinks after the glass is solidified, and holes are easily formed in the secondary grouting holes to influence sealing. And (5) after the glass cement is solidified, checking the sealing condition of the secondary grouting hole, and performing glue filling and sealing on the hole.
(3) Drilling: the drilling process of the drilling comprises the following steps: positioning a hole site, building a drilling machine platform, compounding the hole site, accurately positioning the drilling machine, drilling holes and checking; drilling holes on the upper slope surface of the side slope, wherein the included angle between the downward direction of the drilled holes and the horizontal direction is 20-25 degrees.
(4) Extending the assembled grouting prestressed steel anchor pipe into the drill hole;
(5) primary grouting: the primary grouting body 2 (generally M30 cement slurry) is reversely pressed in from bottom to top of the drill hole 1 through the primary grouting pipe 7, the primary grouting pipe 7 adopts a phi 25mm PVC pipe, in order to ensure that the slurry is filled in the gap of the whole drill hole 1, the primary grouting pipe 7 extends into the hole bottom, the slurry is reversely pressed in from bottom to top through the primary grouting pipe 7, crushed slag and leaked slurry remained at the pipe bottom are pressed out of the hole opening, and the purified slurry is continuously overflowed from the hole opening. In order to prevent the pipe orifice from being blocked by residues when the lower pipe is installed, two rows of quincunx holes with the aperture of 6mm are arranged in the range of 100cm at the tail end of the primary grouting pipe 7, and primary grouting needs to be timely supplemented on site if the retraction of grout at the orifice is found after primary grouting is finished; the anchoring force is provided by the cohesive force of the grouting body 2 and the hole wall of the drill hole 1 at the last time, and secondary high-pressure splitting grouting is performed in the steel pipe in crack development, soft strata of rock strata and soil layers, so that the anchoring force is improved.
(6) Secondary grouting: injecting high-pressure (generally 1-5 MPa) secondary splitting grouting bodies into the steel anchor pipes through the steel anchor pipe openings, splitting grouting holes in the steel anchor pipes at the anchoring sections and the primary grouting bodies, diffusing the split grouting bodies to the periphery, filling gaps among the developed cracks, the weak stratum of the rock stratum and the soil layer, and improving the anchoring force; it has two symbolic slip casting control pressure, one: the instant splitting pressure of the grouting body, namely the pressure for punching the secondary grouting hole and splitting the primary grouting body, is related to the strength of primary grouting and the interval time of primary and secondary grouting. The splitting pressure of the slurry is 1-5 MPa. Secondly, the rock-soil mass is squeezed and cracked, and after the primary grouting body is split, the grout can be driven by the grouting pressure to diffuse around along a channel (mainly a joint crack) in the rock mass. After the 'channel' around the drill hole is filled with the grout, under the action of grouting pressure, the pressure of the grout in the rock-soil body continuously rises until the closed joint crack in the rock body is crushed to generate a new 'channel', and at the moment, the grouting pressure is the rock body crushing pressure.
During secondary grouting (split grouting), the grouting pressure is high, and the opening of the partial grouting pipe needs to be sealed firmly.
In addition, during construction, attention is paid to: firstly, under the action of the instant splitting pressure, slurry cannot run around the drill hole. And secondly, continuous grouting pressure, namely continuous pressure for the grout to diffuse around after secondary fracturing, wherein three conditions can occur according to different strength and structures of rock and soil bodies around the hole. In the first case: after the slurry is split pressure in the twinkling of an eye, it is obviously less than split pressure to last slip casting pressure, and last slip casting pressure can not increase moreover, can not appear rock mass extrusion fracture pressure promptly, and the slip casting volume constantly increases, controls the slip casting volume according to design slip casting volume triple this moment. In the second case: after the instant splitting pressure of the slurry appears, although the continuous grouting pressure is obviously smaller than the splitting pressure, the continuous pressure is continuously increased, the rock mass extrusion cracking pressure can appear, the grouting amount is continuously reduced, the grouting amount is controlled in a double mode, and when the total grouting amount is not more than 3 times of the designed grouting amount and the grouting effect is not obvious (the grouting amount per minute is not more than 0.2-0.5L) after the secondary rock mass extrusion cracking pressure appears, grouting can be stopped by one of the two. In the third case: the continuous grouting pressure is not obviously reduced after the grouting pressure of the slurry is instantaneously split, or the grouting pressure is continuously increased without forming rock mass squeezing crack pressure, the grouting effect is not obvious, and the grouting pressure is controlled according to the allowable pressure (5MPa) that the grouting pressure does not exceed a grouting machine and a grouting pipe.
In addition, if the slope surface slurry leakage phenomenon occurs in the experiment, the grouting is stopped immediately.
(7) Assembling a prestressed anchor cable;
the unbonded steel strand 4 is a high-strength and low-relaxation unbonded prestressed steel strand with the diameter of 15.24mm and the Fptk of 1860MPa, the length is cut according to the designed length, the anchoring section is 10-15 m long, the PE sleeve of the anchoring section needs to be removed, and the steel strand anti-corrosion grease (generally used in butter) on the unbonded steel strand 4 is cleaned;
the stringing ring 5 is made of hard plastic material, and the axis is consistent with the bearing plate. One line is arranged at intervals of 1.5-2m, and is firmly bound by iron wires, so that a centering effect is achieved;
the hooping ring 6 is made of phi 2 iron wires and arranged in the middle of the two wire stringing rings 5, and the unbonded steel stranded wires 4 are firmly bound together.
(8) Installation of a prestressed anchor cable: after primary grouting is finished and before secondary grouting, inserting a prestressed anchor cable into the steel anchor pipe and extending into the bottom of the steel anchor pipe;
(9) tensioning and locking the steel anchor pipe: when the strength of the primary grouting body and the secondary splitting grouting body reaches the design requirement, tensioning the steel anchor pipe to the designed anchoring force, and locking by adopting a shaping nut;
(10) and (3) third grouting: injecting tertiary grouting body into the gap between the free section steel anchor pipe and the protective sleeve at normal pressure through the tertiary grouting pipe until the gap between the free section steel anchor pipe and the protective sleeve is filled;
(11) tensioning and locking the prestressed anchor cable: after the strength of the free section of the steel anchor pipe reaches the design requirement, tensioning and locking the unbonded steel strand until the designed anchoring force is reached, and locking by adopting a shaping anchorage device;
(12) sealing an anchor: after the prestressed anchor cable is tensioned and locked for one month, after the anchoring force is stabilized, a steel casing 13 is fixed on the supporting plate 9 to cover the shaping nut 10 and the shaping anchorage 11, the steel casing 13 is filled with anticorrosive grease 12, and finally the steel casing 13 and the supporting plate 9 are sealed by anchor sealing concrete 14.
Through practical use tests, the invention improves the strength of the rock-soil body and the bonding force between the rock-soil body and the steel anchor pipe by accurately controlling grouting through the steel anchor pipe, and the prestress steel anchor pipe stress mode is changed by implanting the steel strand into the steel anchor pipe through constructing prestress at the bottom of the steel anchor pipe, thereby greatly improving the anchoring force. Has the advantages of reasonable structure, advanced technology, economy, reasonableness, good corrosion prevention effect and the like, and is a novel slope reinforcement technology suitable for slope anchoring.
The technical solution of the present invention is not limited to the limitations of the above specific embodiments, and all technical modifications made according to the technical solution of the present invention fall within the protection scope of the present invention.

Claims (10)

1. A full-bonding type prestressed steel anchor pipe cable structure is characterized by comprising a grouting prestressed steel anchor pipe arranged in the bottom of a drill hole, a prestressed steel anchor cable arranged in the grouting prestressed steel anchor pipe, and an outer anchoring end arranged outside the drill hole and connected with the grouting prestressed steel anchor pipe and the prestressed steel anchor cable; the outer anchoring end comprises a concrete beam arranged on the outer side slope of the drilled hole, a wedge-shaped anchor pier fixed on the outer side wall of the concrete beam, a supporting plate fixed on the wedge-shaped anchor pier, a setting nut, a setting anchorage device, a steel retaining cylinder and anchor sealing concrete, the tail ends of the grouting prestressed steel anchor pipe and the prestressed anchor cable sequentially penetrate through the concrete beam, the wedge-shaped anchor pier and the supporting plate, the tail end of the grouting prestressed steel anchor pipe is locked by the setting nut for a tensioning section, the tail end of the prestressed anchor cable is anchored at the rear end of the setting nut by the setting anchorage device, the steel retaining cylinder is fixed on the supporting plate to cover the setting nut and the setting anchorage device, and finally the steel retaining cylinder and the supporting plate.
2. The fully cementitious prestressed steel anchor pipe cable structure as claimed in claim 1, wherein: the grouting prestressed steel anchor pipe comprises a steel anchor pipe, a conical guide head, a centering frame, a primary grouting pipe and a tertiary grouting pipe, wherein the steel anchor pipe is divided into an anchoring section steel anchor pipe and a free section steel anchor pipe, the conical guide head is arranged at the bottom of the anchoring section steel anchor pipe and extends into the bottom of a drill hole, a plurality of grouting holes are formed in the anchoring section steel anchor pipe, the grouting holes are plugged with glass cement, the centering frame is sleeved outside the wall of the anchoring section steel anchor pipe, the primary grouting pipe is fixed on the outer wall of the steel anchor pipe and extends into the bottom of the drill hole together with the steel anchor pipe for injecting primary grouting into the drill hole, and the tail end of the primary grouting pipe extends out of the drill hole; the free section steel anchor pipe overcoat is equipped with the protecting pipe, form the clearance between sealed and free section steel anchor pipe in protecting pipe bottom and the protecting pipe, the clearance bottom that cubic slip casting pipe front end was fixed between free section steel anchor pipe and protecting pipe is used for pouring into cubic slip casting body in the clearance between free section steel anchor pipe and the protecting pipe into, and cubic slip casting pipe rear end extends outside the drilling.
3. The fully cementitious prestressed steel anchor pipe cable structure as claimed in claim 1, wherein: the prestressed anchor cable comprises a plurality of unbonded steel strands extending into the bottom of the steel anchor pipe and an overhead line ring axially arranged on the inner wall of the steel anchor pipe, the plurality of unbonded steel strands respectively penetrate through a plurality of line passing holes formed in the overhead line ring, and the unbonded steel strands between every two adjacent overhead line rings in the steel anchor pipe in the anchoring section are bound by stirrup rings.
4. The fully cementitious prestressed steel anchor pipe cable structure as claimed in claim 1, wherein: drilling holes on the upper slope surface of the side slope, wherein the included angle between the downward direction of the drilled holes and the horizontal direction is 20-25 degrees.
5. The fully cementitious prestressed steel anchor pipe cable structure as claimed in claim 2, wherein: and a centering frame is arranged on the anchoring section steel anchor pipe every 2.0 m.
6. The fully cementitious prestressed steel anchor pipe cable structure as claimed in claim 3, wherein: and arranging one stringing ring in the steel anchor pipe of the anchoring section at intervals of 1.5-2m, and arranging one stringing ring in the steel anchor pipe of the free section at intervals of 2-3 m.
7. The fully cementitious prestressed steel anchor pipe cable structure as claimed in claim 2, wherein: the tail end of the steel anchor pipe, namely the tensioning section, is processed with a turning thread, the length of the turning thread is 15cm, the tooth pitch is 3mm, and the tail end of the steel anchor pipe, namely the tensioning section, is in threaded connection with the shaping nut.
8. The fully cementitious prestressed steel anchor pipe cable structure as claimed in claim 2, wherein: the front end of the tertiary grouting pipe is fixed 20cm above the bottom of the protective sleeve.
9. The fully cementitious prestressed steel anchor pipe cable structure as claimed in claim 3, wherein: the number of the unbonded steel stranded wires is three, the unbonded steel stranded wires are coated with steel stranded wire anti-corrosion grease and coated with PE (polyethylene) sleeves, and the PE sleeves and the steel stranded wire anti-corrosion grease are removed from the 10-15 m positions of the tail sections of the unbonded steel stranded wires and then anchored at the rear ends of the sizing nuts by using sizing anchors.
10. A construction method of a full-bonding prestressed steel anchor pipe cable structure is characterized by comprising the following steps:
(1) assembling a grouting prestressed steel anchor pipe;
(2) grouting hole sealing: injecting glass cement into the grouting hole by using a cement gun, checking the sealing condition of the grouting hole after the glass cement is solidified, and performing glue filling and sealing on the grouting hole;
(3) drilling: the drilling process of the drilling comprises the following steps: positioning a hole site, building a drilling machine platform, compounding the hole site, accurately positioning the drilling machine, drilling holes and checking;
(4) extending the assembled grouting prestressed steel anchor pipe into the drill hole;
(5) primary grouting: reversely pressing in the primary grouting body from the bottom of the drill hole to the top through the primary grouting pipe, continuously overflowing the purified mud at the drill hole opening, and timely replenishing the primary grouting body on site if the retraction of the hole opening grout is found after the primary grouting is finished;
(6) secondary grouting: injecting high-pressure secondary splitting grouting bodies into the steel anchor pipes through the steel anchor pipe openings, splitting grouting holes in the steel anchor pipes at the anchoring sections and the primary grouting bodies, diffusing the split grouting holes and the primary grouting bodies to the periphery, filling gaps among the soft stratum and the soil layer of the rock stratum, and improving the anchoring force;
(7) assembling a prestressed anchor cable;
(8) installation of a prestressed anchor cable: after primary grouting is finished and before secondary grouting, inserting a prestressed anchor cable into the steel anchor pipe and extending into the bottom of the steel anchor pipe;
(9) tensioning and locking the steel anchor pipe: when the strength of the primary grouting body and the secondary splitting grouting body reaches the design requirement, tensioning the steel anchor pipe to the designed anchoring force, and locking by adopting a shaping nut;
(10) and (3) third grouting: injecting tertiary grouting body into the gap between the free section steel anchor pipe and the protective sleeve at normal pressure through the tertiary grouting pipe until the gap between the free section steel anchor pipe and the protective sleeve is filled;
(11) tensioning and locking the prestressed anchor cable: after the strength of the free section of the steel anchor pipe reaches the design requirement, tensioning and locking the unbonded steel strand until the designed anchoring force is reached, and locking by adopting a shaping anchorage device;
(12) sealing an anchor: after the prestressed anchor cable is tensioned and locked for one month, and after the anchoring force is stabilized, a steel casing is fixed on the supporting plate to cover the shaping nut and the shaping anchorage, the steel casing is filled with anticorrosive grease, and finally the steel casing and the supporting plate are sealed by anchor sealing concrete.
CN202011641215.3A 2020-12-31 2020-12-31 Full-bonding type prestressed steel anchor pipe cable structure and construction method thereof Pending CN112726598A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202011641215.3A CN112726598A (en) 2020-12-31 2020-12-31 Full-bonding type prestressed steel anchor pipe cable structure and construction method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202011641215.3A CN112726598A (en) 2020-12-31 2020-12-31 Full-bonding type prestressed steel anchor pipe cable structure and construction method thereof

Publications (1)

Publication Number Publication Date
CN112726598A true CN112726598A (en) 2021-04-30

Family

ID=75609089

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202011641215.3A Pending CN112726598A (en) 2020-12-31 2020-12-31 Full-bonding type prestressed steel anchor pipe cable structure and construction method thereof

Country Status (1)

Country Link
CN (1) CN112726598A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113670494A (en) * 2021-10-20 2021-11-19 中交投资南京有限公司 Tunnel side wall embedding body grip strength testing device and method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113670494A (en) * 2021-10-20 2021-11-19 中交投资南京有限公司 Tunnel side wall embedding body grip strength testing device and method

Similar Documents

Publication Publication Date Title
CN104775428B (en) Compound-type pre-stvessed anchor cable structure and construction method thereof
CN103410161B (en) Oblique control slip casting steel anchor tube framework and construction method thereof
CN104790393B (en) Double-anchoring-section prestress anchor cable structure and constructing method thereof
CN110939456B (en) High-stress roadway combined ring body beam supporting structure and construction method thereof
CN204703160U (en) Two anchoring section prestressed anchor Cable Structure
CN204703159U (en) Prefabricated anchor head pressure anchor wire structure
CN104790394B (en) Prefabricated anchor head pressure anchor wire structure and construction method thereof
CN102808414B (en) Bonded post-tensioned prestressed anchoring construction method for cast-in-place concrete structure
CN108677943A (en) Repeatedly control slip casting pre-stressed steel anchor pipe anchor cable composite structure and its construction method
CN111576403A (en) Sleeve end plate for realizing grouting connection and PHC tubular pile
CN104863150A (en) Anchor end device of tension-compression pre-stressed anchor cable
CN112726598A (en) Full-bonding type prestressed steel anchor pipe cable structure and construction method thereof
CN106948343B (en) A kind of tonnage anchor cable of tension and compression combination bearing mode and peace method processed
CN102808422B (en) Bonded post-tensioned prestressed construction method for cast-in-place reinforced concrete structure
CN210194627U (en) Hole wall guniting device
CN214783884U (en) Full-bonding type prestressed steel anchor pipe cable structure
CN109252881A (en) Steel pipe cement mortar prestress anchorage cable and its method for protecting support
CN211922611U (en) Adopt single-deck corrugated sleeve pipe and prefabricated anchor section to realize anticorrosive anchor rope structure of double-deck
CN112176994B (en) Construction method of prestressed anchor cable structure suitable for broken rock mass
CN111074886A (en) Anchor rod device for tertiary grouting
CN208933959U (en) Repeatedly control slip casting pre-stressed steel anchor pipe anchor cable composite structure
CN108755677A (en) A kind of prefabricated Inner bolt head anchor cable structure of multiple control slip casting
CN211816216U (en) Anchor rod device for tertiary grouting
CN209099354U (en) A kind of prestress anchorage cable with good durability
CN212612665U (en) Anti-floating anchor rod rigid anchor backing plate capable of applying ultrahigh prestress

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
TA01 Transfer of patent application right
TA01 Transfer of patent application right

Effective date of registration: 20220130

Address after: 100081 Beijing city Haidian District Daliushu Road No. 2

Applicant after: CARS RAILWAY ENGINEERING Research Institute

Address before: 188 Xilin Road, Kunming Economic and Technological Development Zone

Applicant before: Yunnan Construction Investment Holding Group Co., Ltd.

Applicant before: Railway Construction Research Institute of China Academy of Railway Sciences Group Co., Ltd

SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination