CN114215569B - Prestressed anchor rod construction method utilizing magnesium oxide-carbon dioxide carbonization - Google Patents
Prestressed anchor rod construction method utilizing magnesium oxide-carbon dioxide carbonization Download PDFInfo
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- CN114215569B CN114215569B CN202111558472.5A CN202111558472A CN114215569B CN 114215569 B CN114215569 B CN 114215569B CN 202111558472 A CN202111558472 A CN 202111558472A CN 114215569 B CN114215569 B CN 114215569B
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- 238000003763 carbonization Methods 0.000 title claims abstract description 106
- 238000010276 construction Methods 0.000 title claims abstract description 27
- QRGVJYFZZFSGAK-UHFFFAOYSA-N C(=O)=O.[O-2].[Mg+2] Chemical compound C(=O)=O.[O-2].[Mg+2] QRGVJYFZZFSGAK-UHFFFAOYSA-N 0.000 title claims abstract description 11
- 238000002347 injection Methods 0.000 claims abstract description 154
- 239000007924 injection Substances 0.000 claims abstract description 154
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims abstract description 38
- CPLXHLVBOLITMK-UHFFFAOYSA-N Magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims abstract description 31
- 239000000395 magnesium oxide Substances 0.000 claims abstract description 20
- 238000000034 method Methods 0.000 claims abstract description 20
- 239000000292 calcium oxide Substances 0.000 claims abstract description 19
- 235000012255 calcium oxide Nutrition 0.000 claims abstract description 19
- 239000002893 slag Substances 0.000 claims abstract description 18
- 239000010802 sludge Substances 0.000 claims abstract description 18
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 9
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 8
- 230000008569 process Effects 0.000 claims abstract description 8
- 238000004140 cleaning Methods 0.000 claims abstract description 5
- 238000009423 ventilation Methods 0.000 claims description 57
- 238000013461 design Methods 0.000 claims description 53
- 239000000463 material Substances 0.000 claims description 40
- 239000002002 slurry Substances 0.000 claims description 38
- 239000002910 solid waste Substances 0.000 claims description 30
- 239000000843 powder Substances 0.000 claims description 24
- 230000005284 excitation Effects 0.000 claims description 18
- 238000005553 drilling Methods 0.000 claims description 17
- 239000007787 solid Substances 0.000 claims description 13
- 239000008187 granular material Substances 0.000 claims description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 claims description 9
- 230000001105 regulatory effect Effects 0.000 claims description 9
- 238000012423 maintenance Methods 0.000 claims description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 5
- 239000003638 chemical reducing agent Substances 0.000 claims description 5
- 238000006073 displacement reaction Methods 0.000 claims description 5
- 239000002245 particle Substances 0.000 claims description 5
- 239000004568 cement Substances 0.000 claims description 4
- 230000007797 corrosion Effects 0.000 claims description 4
- 238000005260 corrosion Methods 0.000 claims description 4
- 238000011835 investigation Methods 0.000 claims description 4
- 239000003245 coal Substances 0.000 claims description 3
- 238000005507 spraying Methods 0.000 claims description 3
- 229910001220 stainless steel Inorganic materials 0.000 claims description 3
- 239000010935 stainless steel Substances 0.000 claims description 3
- 238000012360 testing method Methods 0.000 claims description 3
- 239000011435 rock Substances 0.000 abstract description 34
- 238000004873 anchoring Methods 0.000 abstract description 15
- 230000008901 benefit Effects 0.000 abstract description 6
- 230000007613 environmental effect Effects 0.000 abstract description 4
- 238000002513 implantation Methods 0.000 abstract description 2
- 239000003469 silicate cement Substances 0.000 abstract 1
- 238000005273 aeration Methods 0.000 description 22
- 239000003513 alkali Substances 0.000 description 10
- 239000002689 soil Substances 0.000 description 9
- 239000010419 fine particle Substances 0.000 description 7
- 229910000831 Steel Inorganic materials 0.000 description 5
- 239000010959 steel Substances 0.000 description 5
- 239000001569 carbon dioxide Substances 0.000 description 4
- 229910002092 carbon dioxide Inorganic materials 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000011440 grout Substances 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 238000009412 basement excavation Methods 0.000 description 3
- 230000002787 reinforcement Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 238000007711 solidification Methods 0.000 description 2
- 230000008023 solidification Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- 239000011398 Portland cement Substances 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000035425 carbon utilization Effects 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- -1 containing magnesium Chemical class 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 238000007569 slipcasting Methods 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 230000001960 triggered effect Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D20/00—Setting anchoring-bolts
- E21D20/02—Setting anchoring-bolts with provisions for grouting
- E21D20/021—Grouting with inorganic components, e.g. cement
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
- C04B28/10—Lime cements or magnesium oxide cements
- C04B28/105—Magnesium oxide or magnesium carbonate cements
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B40/00—Processes, in general, for influencing or modifying the properties of mortars, concrete or artificial stone compositions, e.g. their setting or hardening ability
- C04B40/02—Selection of the hardening environment
- C04B40/0231—Carbon dioxide hardening
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/74—Means for anchoring structural elements or bulkheads
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D20/00—Setting anchoring-bolts
- E21D20/02—Setting anchoring-bolts with provisions for grouting
- E21D20/028—Devices or accesories for injecting a grouting liquid in a bore-hole
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D21/00—Anchoring-bolts for roof, floor in galleries or longwall working, or shaft-lining protection
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/00663—Uses not provided for elsewhere in C04B2111/00 as filling material for cavities or the like
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
- C04B2111/00724—Uses not provided for elsewhere in C04B2111/00 in mining operations, e.g. for backfilling; in making tunnels or galleries
-
- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
- C04B2111/70—Grouts, e.g. injection mixtures for cables for prestressed concrete
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D2250/00—Production methods
- E02D2250/0046—Production methods using prestressing techniques
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D2600/00—Miscellaneous
- E02D2600/30—Miscellaneous comprising anchoring details
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Structural Engineering (AREA)
- Mining & Mineral Resources (AREA)
- Ceramic Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Geochemistry & Mineralogy (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Health & Medical Sciences (AREA)
- Toxicology (AREA)
- Piles And Underground Anchors (AREA)
Abstract
The invention discloses a method for constructing a prestressed anchor rod by utilizing magnesium oxide-carbon dioxide carbonization, belonging to the technical field of anchor rod construction in slope engineering and tunnel engineering. The construction method mainly comprises the steps of paying off positioning, hole digging and cleaning, anchor rod implantation, cylinder pulling grouting, gas injection carbonization, prestressing, carbonization of an enlarged head area, construction ending and the like, and the steps work sequentially, so that the construction efficiency and quality are greatly improved. The anchor rod is specially provided with the variable cross section so as to enhance the anchoring property between the anchor rod and the rock mass; the springs are specially arranged to adapt to large deformation of the rock mass, and prestress is applied by adjusting the positions of the nuts and the lifting disc so as to offset the ground stress in the surrounding rock. The expanding head and the carbonization layer in the invention are mainly low-carbon light-burned magnesia and slag, and are also doped with a certain amount of quicklime and sludge incineration ash to replace the traditional silicate cement, and the two areas are independently aerated and carbonized, so that a large amount of CO is consumed in the reinforcing process 2 The gas and carbonization curing time is short, and the method has huge environmental benefit and social benefit.
Description
Technical Field
The invention belongs to the technical field of geotechnical engineering slope or roadway reinforcement treatment, and particularly relates to a method for applying a prestressed anchor rod by utilizing magnesium oxide-carbon dioxide carbonization.
Background
In the construction process of tunnel engineering, mining engineering, foundation pit engineering or slope engineering, the phenomenon that personnel and engineering safety are endangered due to stratum deformation, collapse or slope instability often occurs, and the side slope or foundation pit needs to be reinforced. The existing reinforcing mode is mostly anchor rod and grouting, namely the tensile and shear resistance of the stratum or the slope are improved by arranging the anchor rod, so that the deformation of the stratum is controlled, and the overall stability of the stratum is improved. The anchor bolt support is used as an active support mode, is an effective measure for inhibiting deformation of a rock and soil body after excavation and reinforcing unstable rock and is widely applied to side slope support. Along with the increasing complexity of underground space and foundation pit excavation conditions and the increase of surrounding rock disturbance caused by excavation activities, the deformation of the surrounding rock is gradually increased, so that the traditional anchoring support technology exposes obvious problems. For example, the anchoring and fastening performance between the anchor rod and the rock body are poor, so that the rock body is cracked and loosened, and the anchor rod cannot fully exert the supporting capability; the common prestressed anchor rod or grouting anchor rod is limited by the deformation capacity of the material, and when the surrounding rock is excessively deformed, the anchor rod is broken, the anchor head is damaged and the like.
Under the ground stress condition, engineering problems caused by large deformation sometimes occur, the large deformation problem is difficult to effectively solve, and when surrounding rock is deformed greatly, the anchor rod is broken and damaged due to the fact that the anchor rod cannot adapt to the large deformation of the surrounding rock, so that the anchor rod support is invalid. Patent CN209212272U discloses an extensible anchor rod which can adapt to the large deformation of surrounding rock, and when the anchor rod is subjected to external force, the anchor rod starts to generate displacement and release energy, so that the early-stage supporting strength is reduced, and the damage strength is lower than that of the common anchor rod. Patent CN1182810a discloses a large deformation self-adaptive energy release anchor rod, which comprises a rod body and an inner stepped tube barrel on the rear section of the rod body, wherein the rod body and the tube barrel can relatively displace, and the support function is provided by friction force generated during displacement. Patent CN111412003a discloses a scalable slip casting stock of self-adaptation large deformation tunnel, and this stock utilizes the extension spring to solve the problem of large deformation, but the anchoring force of stock all comes from the contact stress between sleeve and country rock, and when the country rock takes place to warp, the compactness of anchoring between sleeve and the country rock and the anchoring force that the stock can provide will reduce, even lead to the inefficacy of whole anchor support system.
The prestressed anchor rod is also widely used as an initial support of a tunnel structure, and the soil body or the rock mass is reinforced by applying prestressing force, so that the stability of the soil body or the rock mass is improved, and collapse of the soil body or the rock mass is avoided. However, most of prestress tensioning of the anchor rods is applied during site construction, and the condition that the prestress cannot reach a design value easily occurs. As patent CN110670599a discloses a hollow grouting prestressed anchor and a construction method thereof, including a hollow rod body, an anchor head, a nut and a backing plate, the maximum tension that can be achieved is greatly increased compared with the traditional anchor, so that the safety performance of the anchor supporting structure is improved, but the prestress of the anchor is applied by tensioning, and the design value is likely to be not achieved, so that the normal application of the anchor is affected. Patent CN11946375a discloses a sectional grouting anchor rod, but the anchor rod is easy to deform under the action of shear stress, and the anchor rod cannot move to a preset position under the influence of slurry, so that the opening of a grouting plug at the next stage and the subsequent grouting work cannot be triggered. Patent CN112360530a discloses a grouting anchor rod for geotechnical engineering construction, which has better impermeability and overall stability, but cannot solve the problems of large deformation and high ground stress which may occur in stratum. Patent CN112253194a discloses a supporting device and a supporting method for grouting an anchor rod rope, but in the construction process, the anchor rod or the anchor rod rope needs to be placed for more than half a month after being put in until a rock mass is naturally cracked, and the method has long construction time and small application range. In addition, patent CN112360534a discloses a full-anchor grouting anchor rod and an anchoring method thereof, the slurry used in grouting of the anchor rod is cement slurry, the solidification time is long, and the device increases the anchoring length of the anchor rod by unscrewing the convex body at the tip end part of the internal threaded rod, but the increase range of the anchoring length and the anchoring capacity is extremely limited.
In combination with the defects existing in the existing anchor rod structure, the ground stress treatment and the large deformation rock mass structure, the application of the anchoring treatment method with low carbon, high efficiency, high tensile and shearing resistance and adaptability to the large deformation rock mass has become an important topic to be solved in the industry on the basis of the current situation and the demand of the rapid development of engineering construction in China. Therefore, the pre-stress anchor rod construction method utilizing magnesium oxide-carbon dioxide carbonization is provided, and has very important engineering significance for rock mass reinforcement treatment in slope and roadway engineering.
Disclosure of Invention
In view of the shortcomings in the background art, the invention aims to provide a prestress anchor rod construction method utilizing magnesium oxide-carbon dioxide carbonization, which solves the defects or problems of low anchor rod anchoring capability, poor adaptability to large deformation, long anchoring treatment period, low stability, poor environmental and economic benefits and the like in the prior art. According to the invention, variable-section anchor rods with different lengths are selected according to actual conditions of rock stratum, so that the anchoring property between the anchor rods and rock mass is enhanced; the anchor rod can be prestressed to cope with ground stress which may occur in the stratum; the anchor rod is specially provided with a spring device to adapt to large deformation generated by the rock mass and improve the supporting capacity; the grouting of the anchor rod takes low-carbon magnesium oxide and industrial waste residues as main materials, and absorbs a large amount of CO 2 The gas can quickly improve the strength of the slurry, and has the remarkable advantages of low carbon, environmental protection and high construction efficiency.
In order to solve the technical problems, the invention adopts the following technical scheme: a method for constructing a prestressed anchor rod carbonized by magnesium oxide-carbon dioxide, which is characterized by comprising the following steps:
a. paying-off positioning: determining the position, the distance, the depth, the diameter and the inclination angle of the anchor rod holes according to the investigation data and the design file, determining the depth, the length and the diameter of the variable section of the anchor rod, and paying off on the slope surface;
b. hole digging and hole cleaning: according to the anchor rod parameters determined by paying off positioning, rotary drilling is carried out to a designed depth by using an anchor rod drilling machine, the rotary diameter of a drill bit of the drilling machine is adjusted at the designed variable cross section position and the bottom, an anchor rod hole with the variable cross section and an enlarged head is formed by rotary drilling, and finally the anchor rod hole is cleaned by using a high-pressure air gun;
c. implanting an anchor rod: implanting a qualified anchor rod into the anchor rod hole, finely adjusting the anchor rod to enable a telescopic carbonizer of the anchor rod to be aligned with the variable cross section of the anchor rod hole, and then fixing the air injection channel A by screwing a nut;
the anchor rod comprises an air injection hole A, an air injection hole B, a nut, an air injection channel A, an air injection channel B, a telescopic carbonizer, a sleeve, an expansion head, an grouting channel, an air injection hole area C, an air injection hole area A and an air injection hole area B; the gas injection hole areas B are annular, the gas injection hole areas B are arranged on the side face of the gas injection channel B at intervals, telescopic carbonizers are arranged between the adjacent gas injection hole areas B, each telescopic carbonizer comprises a carbonizer head, a gas injection hole area C, a limiting cylinder, a lifting disc B, a spring B and a gas injection channel C, one end of the gas injection channel C is communicated with the gas injection channel B, the other end of the gas injection channel C is communicated with the carbonizer head, and the gas injection hole area C is arranged on the carbonizer head; the air injection channel A is fixedly connected with the lifting disk A, the air injection channel B is fixedly connected with the limiting disk, the lifting disk A is connected with the limiting disk through a spring A, and the relative displacement between the lifting disk A and the limiting disk is limited by a nut;
d. pulling out a cylinder for grouting: closing the gas injection hole A and the gas injection hole B, connecting a grouting pump with the upper end of a grouting channel on the sleeve, starting the grouting pump, adjusting grouting pressure, spraying slurry from the lower end of the grouting channel in the wall of the sleeve, rotating the sleeve and pulling out the sleeve after the slurry in the enlarged head is filled, continuously injecting the slurry into a carbonization layer area outside the anchor rod, synchronously injecting the slurry and pulling out the sleeve, and closing the grouting pump when the slurry fills the carbonization layer area outside the anchor rod and the sleeve is completely pulled out, so as to finish cylinder pulling grouting;
the slurry consists of fine granules with the average particle size smaller than 1mm, water and a water reducing agent, wherein the fine granules consist of alkaline gel excitation materials and industrial solid waste, the alkaline gel excitation materials consist of light burned magnesium oxide and quicklime powder, and the industrial solid waste consists of slag powder and sludge incineration ash; the water-solid ratio of the slurry is 0.4-0.7, and the higher the content of the alkaline material is, the larger the water-solid ratio is; the alkaline gel excitation material and the industrial solid waste respectively account for 20-50% and 50-80% of the fine granules, the light burned magnesia and the quicklime powder respectively account for 70-100% and 0-30% of the alkaline gel excitation material, and the slag powder and the sludge incineration ash respectively account for 70-85% and 15-30% of the industrial solid waste;
e. gas injection carbonization: CO is processed by 2 The high-pressure gas tank is connected with the gas injection hole B, a ventilation valve B on the gas injection hole B is opened, and the ventilation pressure is regulated to a first design ventilation pressure, so that CO 2 The gas is diffused to the carbonization layer area through the gas injection hole area B and the telescopic carbonizer on the gas injection channel B, after the ventilation maintenance is carried out until the first designed carbonization time, the ventilation valve B is closed,gas injection carbonization of the carbonized layer is completed;
the CO 2 Collecting compressed high pressure CO from high carbon emission coal and cement plants 2 CO used 2 The concentration is greater than 40%, the first design ventilation pressure is 100-200 kPa, the first design carbonization time is 3-12 hours, the first design ventilation pressure and the first design carbonization time are determined according to the thickness of the carbonization layer, and the thicker the carbonization layer is, the greater the first design ventilation pressure and the first design carbonization time are;
f. and (3) applying prestress: the position of a lifting disk A fixedly connected with the air injection channel A is adjusted through a rotating nut, so that the designed prestress is achieved;
g. carbonization enlarged head region: CO is processed by 2 The high-pressure air tank is connected with the air injection hole A, a ventilation valve A on the air injection hole A is opened, and the ventilation pressure is regulated to a second design ventilation pressure to enable CO to be discharged 2 The gas is diffused to the expansion head area through the gas injection hole area A of the gas injection channel A, and after ventilation maintenance is carried out until the second designed carbonization time, the ventilation valve A is closed to finish gas injection carbonization of the expansion head area;
the second design ventilation pressure is 200-400 kPa, the second design carbonization time is 6-12 hours, the second design ventilation pressure and the second design carbonization time are determined according to the length of the anchor rod and the diameter of the enlarged head, and the larger the length of the anchor rod and the diameter of the enlarged head, the larger the second design ventilation pressure and the second design carbonization time;
h. and (3) performing construction ending: unloading the vent valve A, enabling the micro detector to enter from the gas injection hole A, advancing inwards at a constant speed along the gas injection channel A, checking carbonization reinforcing effects of the carbonization layer and the enlarged head area in the advancing process, and performing secondary carbonization treatment on the unqualified area if the carbonization layer and the enlarged head area are unqualified; and when the test is qualified, the nut is removed, and the tail of the anchor rod is subjected to corrosion protection treatment, so that the anchor rod is finished.
As an improvement of the invention, the sleeve is made of hard plastic or stainless steel with the diameter of 100-300mm, the sleeve is pulled out to rotate alternately clockwise and anticlockwise, and the pulled sleeve can be recycled; the grouting channels are uniformly distributed in the wall of the sleeve, the inner diameter of each grouting channel is smaller than the wall thickness of the sleeve, the number of the grouting channels is 3-12 according to the diameter of the sleeve, and the larger the diameter of the sleeve is, the more the number of the grouting channels is.
Compared with the prior art, the invention has the following technical advantages and beneficial effects:
(1) The anchor rod is specially provided with a variable cross section, the anchoring and fastening performance between the anchor rod and the carbonization layer and between the carbonization layer and the rock mass are enhanced, and the supporting capability of the anchor rod can be fully exerted and improved.
(2) The special telescopic device of the anchor rod can adapt to the large deformation of stratum, increase the elongation rate of the deformation of the anchor rod, effectively release the energy generated by the deformation of surrounding rock, greatly improve the breaking strength and the early support capability of the anchor rod, and have good support effect and long-term stability.
(3) The stopper and the nut are specially arranged on the anchor rod structure, the position of the stopper and the size of the prestress of the anchor rod are accurately adjusted through the rotation number of the nut, when a certain ground stress is generated in surrounding rock, the ground stress in a rock soil layer can be counteracted by the anchor rod prestress, so that the anchor rod and the carbonized layer after carbonization and solidification can adapt to the deformation of the rock soil layer, and an anchor rod support system is protected.
(4) The anchor rod structure body is specially provided with the gas injection channel A and the gas injection channel B, and the gas injection hole area A, the gas injection hole area B and the gas injection hole area C, so that independent ventilation and carbonization of the expansion head and the carbonization layer are realized, and the ventilation and carbonization efficiency of the expansion head and the carbonization layer is remarkably improved.
(5) The slurry used in the invention mainly comprises light burned magnesia and slag, and is also doped with a certain amount of quicklime powder and sludge incineration ash to replace the traditional Portland cement, and the cementing material has obvious low-carbon and environment-friendly characteristics; meanwhile, the light burned magnesia and the quicklime have a certain expansibility, so that the friction combination between the anchor rod carbonized layer and the rock-soil layer is promoted to a certain extent.
(6) The cementing material in the invention is prepared by CO 2 The carbonization plays a role, the ventilation and carbonization time is short, the strength is fast to increase, the maintenance time of the traditional grouting anchor rod is greatly reduced, and the construction efficiency of the anchor rod is improved; at the same time, the invention can absorb CO in a large amount 2 The carbon utilization in the surrounding rock reinforcement process of the rock soil is realized, and the method has important significance for energy conservation, emission reduction and environmental protection.
Drawings
In order to more clearly illustrate the technical solutions of the present invention, the drawings required in the embodiments will be briefly described below, and it is obvious that the following drawings are only some embodiments of the present invention, and other drawings may be obtained according to the drawings for those skilled in the art.
FIG. 1 is a schematic illustration of the construction steps of a prestressed anchor rod carbonized with magnesia-carbon dioxide (a-hole digging and clearing, b-anchor rod implantation, c-cylinder grouting, d-gas injection carbonization, e-prestressing, f-carbonization expanding head area);
FIG. 2 is a schematic illustration of a prestressed anchor utilizing magnesia-carbon dioxide carbonization;
FIG. 3 is a schematic view of a telescopic carbonizer of a prestressed anchor rod carbonized with magnesia-carbon dioxide;
FIG. 4 is a schematic view of the exterior of a pre-stressed anchor carbonized with magnesium oxide-carbon dioxide with the sleeve removed;
FIG. 5 is a top view of a prestressed anchor carbonized with magnesia-carbon dioxide;
in the figure: 1. the device comprises an air injection hole A,2, a nut, 3, a steel plate, 4, an air injection channel A,5, an air injection channel B,6, a telescopic carbonizer, 7, a sleeve, 8, a limit disc, 9, a spring A,10, a lifting disc A,11, a brush, 12, an enlarged head, 13, a carbonizer, 14, an air injection hole area C,15, a limit cylinder, 16, a lifting disc B,17, a spring B,18, an air injection channel C,19, an air injection hole area A,20, an air injection hole area B,21, an grouting channel, 22, an air injection hole B,23, a ventilation valve A,24 and a ventilation valve B.
Detailed Description
In the description of the present invention, the positional relationship indicated by "upper", "lower", "top", "bottom", "inner", "outer", etc. are positional relationships shown in the drawings, and are merely for convenience of description of the present invention, and are not indicative or implying the specific orientations referred to. The specific features in the implementation steps are detailed description of the technical scheme, and are not limitations of the technical scheme of the application. I.e. the technical features in the implementation steps may be combined with each other without conflict. In order to make the technical means, the creation characteristics, the achievement of the purpose and the effect of the present invention easy to understand, the technical scheme will be further described below with reference to the drawings and the specific embodiments of the specification. The present invention will be described in further detail with reference to the following drawings, in order to make the objects, technical solutions and advantages of the present invention more apparent.
Referring to fig. 1, a specific description is provided in connection with fig. 2-5.
A method for constructing a prestressed anchor rod carbonized by magnesium oxide-carbon dioxide, which is characterized by comprising the following steps:
a. paying-off positioning: determining the position, the distance, the depth, the diameter and the inclination angle of the anchor rod holes according to the investigation data and the design file, determining the depth, the length and the diameter of the variable section of the anchor rod, and paying off on the slope surface;
b. hole digging and hole cleaning: according to the anchor rod parameters determined by paying-off positioning, rotary drilling is carried out to a designed depth by using an anchor rod drilling machine, the rotary diameter of a drill bit of the drilling machine is adjusted at the designed variable cross section position and the bottom, an anchor rod hole with the variable cross section and an enlarged head 12 is formed by rotary drilling, and finally the anchor rod hole is cleaned by using a high-pressure air gun (as shown in fig. 1 (a));
c. implanting an anchor rod: implanting a qualified anchor rod into the anchor rod hole, finely adjusting the anchor rod to enable a telescopic carbonizer 6 of the anchor rod to be aligned with the variable cross section of the anchor rod hole, and then screwing a nut 2 to fix an air injection channel A4 (shown in the figure 1 (b));
the anchor rod comprises a grouting device, an air injection device and a telescopic device, wherein the grouting device comprises a sleeve 7 and a grouting channel 21, the sleeve 7 is sleeved outside the anchor rod device, and the grouting channel 21 is arranged inside the wall of the sleeve 7; the inner diameter of the grouting channels 21 is smaller than the wall thickness of the sleeve 7, the number of the grouting channels 21 is 3-12 according to the diameter of the sleeve 7, and the larger the diameter of the sleeve 7 is, the more the number of the grouting channels 21 is; the gas injection device comprises a gas injection channel A4, a gas injection channel B5, a telescopic carbonizer 6, an expansion head 12, a gas injection hole area A19, a gas injection hole area B20, a gas injection hole A1, a gas injection hole B22, a vent valve A23 and a vent valve B24; the telescopic carbonizer 6 is fixedly arranged outside the gas injection channel B5, and the telescopic carbonizer 6 comprises a carbonizer head 13, a gas injection hole area C14, a limiting cylinder 15, a lifting disc B16, a spring B17 and a gas injection channel C18; the lower part of the gas injection channel A4 is communicated with the expansion head 12, the outer surface of the expansion head 12 is provided with a gas injection hole area A19, a gas injection hole A1 is arranged above the gas injection channel A4, a vent valve A23 is arranged on the gas injection hole A1, a gas injection hole B22 is arranged on the steel plate 3 above the gas injection channel B5, a vent valve B24 is arranged on the gas injection hole B22, the gas injection channel B5 is communicated with a gas injection channel C18 in the telescopic carbonizer 6, the outer surface of the gas injection channel B5 is provided with a gas injection hole area B20, the gas injection channel C18 is communicated with the carbonizer 13, the carbonizer 13 is provided with a gas injection hole area C14, the spring B17 is circumferentially arranged below the lifting disc B16, and the other end of the spring B17 is fixedly connected with the housing of the telescopic carbonizer 6; the limiting cylinder 15 is fixedly arranged above the telescopic carbonizer 6 and sleeved outside the gas injection channel C18; the telescopic device comprises a steel plate 3, a nut 2, a limiting disc 8, a spring A9, a lifting disc A10 and a brush 11, wherein the steel plate 3 is erected above an air injection channel B5, the nut 2 is arranged above the steel plate 3, the limiting disc 8 and the lifting disc A10 are arranged inside the air injection channel B5 and outside the air injection channel A4, the limiting disc 8 is fixedly connected with the inner wall of the air injection channel B5, the lifting disc A10 is fixedly connected with the outer wall of the air injection channel A4, the limiting disc 8 is connected with the lifting disc A10 through the spring A9, and the relative displacement between the lifting disc A10 and the limiting disc 8 is limited by the nut 2; when the nut 2 is detached, the whole combined by the air injection channel A4, the expansion head 12 and the lifting disk A10, the whole combined by the air injection channel B5 and the limiting disk 8 can slide relatively through the spring A9 so as to adapt to the large deformation of the rock and soil layer (as shown in figures 2-5);
d. pulling out a cylinder for grouting: closing the gas injection hole A1 and the gas injection hole B22, connecting a grouting pump with the upper end of a grouting channel 21 on the sleeve 7, starting the grouting pump, adjusting grouting pressure, spraying slurry from the lower end of the grouting channel 21 in the wall of the sleeve 7, rotating the sleeve 7 and pulling out the sleeve after the slurry in the enlarged head 12 is filled, continuously injecting the slurry into a carbonization layer area outside the anchor rod, synchronously injecting the slurry and pulling out the sleeve 7, and closing the grouting pump when the slurry fills the carbonization layer area outside the anchor rod and the sleeve 7 is completely pulled out, so as to finish pulling cylinder grouting (as shown in (c) of fig. 1);
the slurry consists of fine granules with the average particle size smaller than 1mm, water and a water reducing agent, wherein the fine granules consist of alkaline gel excitation materials and industrial solid waste, the alkaline gel excitation materials consist of light burned magnesium oxide and quicklime powder, and the industrial solid waste consists of slag powder and sludge incineration ash; the water-solid ratio of the slurry is 0.4-0.7, and the higher the content of the alkaline material is, the larger the water-solid ratio is; the alkaline gel excitation material and the industrial solid waste respectively account for 20-50% and 50-80% of the fine granules, the light burned magnesia and the quicklime powder respectively account for 70-100% and 0-30% of the alkaline gel excitation material, and the slag powder and the sludge incineration ash respectively account for 70-85% and 15-30% of the industrial solid waste;
e. gas injection carbonization: CO is processed by 2 The high-pressure gas tank is connected with the gas injection hole B22, a vent valve B24 on the gas injection hole B22 is opened and regulated to a first design vent pressure, so that CO 2 The gas diffuses to the carbonization layer area through the gas injection hole area B20 and the telescopic carbonizer 6 on the gas injection channel B5, and after the gas is aerated and cured to the first designed carbonization time, the vent valve B24 is closed to finish gas injection carbonization of the carbonization layer (as shown in (d) of fig. 1);
the CO 2 Collecting compressed high pressure CO from high carbon emission coal and cement plants 2 CO used 2 The concentration is greater than 40%, the first design ventilation pressure is 100-200 kPa, the first design carbonization time is 3-12 hours, the first design ventilation pressure and the first design carbonization time are determined according to the thickness of the carbonization layer, and the thicker the carbonization layer is, the greater the first design ventilation pressure and the first design carbonization time are;
f. and (3) applying prestress: the position of a lifting disk A10 fixedly connected with the air injection channel A4 is adjusted by rotating the nut 2 so as to achieve the designed prestress (as shown in (e) of fig. 1);
g. carbonization enlarged head region: CO is processed by 2 The high-pressure air tank is connected with the air injection hole A1, a ventilation valve A23 on the air injection hole A1 is opened, and the ventilation pressure is regulated to a second design ventilation pressure to enable CO to be discharged 2 The gas is diffused to the area of the enlarged footing 12 through the gas injection hole area A19 of the gas injection channel A4, and after the ventilation maintenance is carried out until the second designed carbonization time, the ventilation valve A23 is closed, so that the gas injection carbonization of the area of the enlarged footing 12 is completed (as shown in (f) of FIG. 1);
the second design ventilation pressure is 200-400 kPa, the second design carbonization time is 6-12 hours, the second design ventilation pressure and the second design carbonization time are determined according to the length of the anchor rod and the diameter of the enlarged head 12, and the larger the length of the anchor rod and the diameter of the enlarged head 12, the larger the second design ventilation pressure and the second design carbonization time;
h. and (3) performing construction ending: unloading the vent valve A23, enabling the micro detector to enter from the gas injection hole A1, advancing inwards at a constant speed along the gas injection channel A4, checking carbonization reinforcing effects of the carbonization layer and the enlarged head 12 area in the advancing process, and if the detection is unqualified, performing secondary carbonization treatment on the unqualified area; and when the test is qualified, the nut 2 is removed, and the tail of the anchor rod is subjected to corrosion protection treatment, so that the anchor rod construction is completed.
As another improvement of the invention, the sleeve 7 is made of hard plastic or stainless steel with the diameter of 100-300mm, the sleeve 7 is pulled out by clockwise and anticlockwise alternating rotation, and the pulled sleeve 7 can be recycled; the grouting channels 21 are uniformly distributed in the wall of the sleeve 7, the inner diameter of the grouting channels 21 is smaller than the wall thickness of the sleeve 7, the number of the grouting channels 21 is 3-12 according to the diameter of the sleeve 7, and the larger the diameter of the sleeve 7 is, the more the number of the grouting channels 21 is.
The following will describe the geometric figures 1-5 and five specific embodiments.
The slurry used in the invention consists of fine granules with the average particle size smaller than 1mm, water and a water reducing agent, wherein the fine granules consist of alkaline gel excitation materials and industrial solid waste, the alkaline gel excitation materials consist of light burned magnesia and quicklime powder, the industrial solid waste consists of slag powder and sludge incineration ash, and the water-solid ratio of the slurry ranges from 0.4 to 0.7. The greater the water-to-solid ratio, i.e., the ratio of the volume of water to the volume of solid phase, the greater the difficulty of gas entry into the slurry, requiring a corresponding increase in aeration pressure and aeration carbonization time. The alkaline gel excitation material and the industrial solid waste in the slurry respectively account for 20-50% and 50-80% of the fine particles, the light burned magnesia and the quicklime powder respectively account for 70-100% and 0-30% of the alkaline gel excitation material, the slag powder and the sludge incineration ash respectively account for 70-85% and 15-30% of the industrial solid waste, the more the alkaline materials are, the larger the ratio is, the more carbonization generated substances are, the more carbonization time is needed, and therefore the ventilation pressure and the ventilation carbonization time are also needed to be increased; the activity of industrial solid waste (slag and sludge incineration ash) is lower, and the industrial solid waste is excited by the alkaline cementing material for a certain time, so that when the proportion of the industrial solid waste is increased, the ventilation and carbonization time is increased to ensure the reinforcing effect of the industrial solid waste. The sleeve 7 is pulled out in a clockwise and anticlockwise alternative rotation mode, so that the anchor rod hole is prevented from being damaged, the clockwise and anticlockwise alternative rotation can ensure grouting uniformity, and the integrity of the carbonized layer and the enlarged head 12 area is ensured.
Working principle: the carbonization layer and the enlarged head area of the anchor rod are injected with slurry composed of fine particles with average particle diameter less than 1mm, water and water reducing agent, the slurry contains active magnesium oxide, quicklime, slag powder and sludge incineration ash, the magnesium oxide and the quicklime can excite the slag powder and the sludge incineration ash to generate alkali excitation reaction to generate gelled substances, so that the carbonization layer and the enlarged head area have certain initial strength, basically form shape and introduce CO 2 The active magnesium oxide and the quicklime are subjected to carbonization reaction to generate a series of corresponding basic carbonates mainly containing magnesium, so that the strength of the carbonized layer and the enlarged head 12 area is further and rapidly improved, and the carbonized layer and the enlarged head 12 area which are reinforced by alkali excitation and carbonized are combined to act together, so that the overall supporting strength of the anchor rod is improved.
Firstly, determining the position, the distance, the depth, the diameter and the inclination angle of anchor rod holes according to investigation data and design files, determining the depth, the length and the diameter of the variable section of the anchor rod, and paying off on the slope surface of the side slope; then according to the anchor rod parameters determined by paying-off positioning, drilling holes to the designed depth by using an anchor rod drilling machine, adjusting the rotating diameter of a drilling bit of the drilling machine at the designed variable cross section position and the bottom, forming anchor rod holes with variable cross sections and enlarged heads 12 by rotary drilling, and cleaning the anchor rod holes by using a high-pressure air gun (as shown in fig. 1 (a)); then the anchor rod is implanted into the anchor rod hole, the anchor rod is finely adjusted to lead the telescopic carbonizer 6 of the anchor rod to be aligned with the variable cross section of the anchor rod hole, and then the nut 2 is screwed and adjusted to fix the air injection channel A4 (as shown in the figure 1 (b)); then the gas injection hole A1 and the gas injection hole B22 are closed, the grouting pump is connected with the upper end of the grouting channel 21 on the sleeve 7, the grouting pump is started, and the grouting pressure is regulated to enable the slurry to flow fromThe lower end of the grouting channel 21 in the wall of the sleeve 7 is sprayed out, after the grout in the enlarged head 12 is filled, the sleeve 7 is alternately rotated clockwise and anticlockwise and pulled out, the grout is continuously injected into the carbonization layer area outside the anchor rod, the grout injection and the sleeve 7 pulling out are synchronously carried out, and when the grout fills the carbonization layer area outside the anchor rod and the sleeve 7 is completely pulled out, the grouting pump is closed, and the sleeve pulling grouting is completed (as shown in (c) of fig. 1); CO is processed by 2 The high-pressure gas tank is connected with the gas injection hole B22, a vent valve B24 on the gas injection hole B22 is opened, and the first design vent pressure is regulated to enable CO to be discharged 2 The gas diffuses to the carbonization layer area through the gas injection hole area B20 and the telescopic carbonizer 6 on the gas injection channel B5, and after ventilation maintenance, the ventilation valve B24 is closed to finish gas injection carbonization of the carbonization layer (as shown in fig. 1 (d)); the position of a lifting disk A10 fixedly connected with the air injection channel A4 is adjusted by rotating the nut 2 so as to achieve the designed prestress (as shown in (e) of fig. 1); carbonization enlarged head 12 region: CO is processed by 2 The high-pressure air tank is connected with the air injection hole A1, a ventilation valve A23 on the air injection hole A1 is opened, and the second design ventilation pressure is regulated to enable CO to be discharged 2 The gas is diffused to the area of the enlarged head 12 through the gas injection hole area A19 of the gas injection channel A4, and after ventilation maintenance, the ventilation valve A23 is closed to finish gas injection carbonization of the area of the enlarged head 12 (as shown in fig. 1 (f));
finally, ending is performed, the vent valve A23 is removed, the micro detector enters from the air injection hole A1 and moves inwards at a constant speed along the air injection channel A4, the carbonization reinforcing effect of the carbonization layer and the area of the enlarged head 12 is checked in the moving process, and when the carbonization reinforcing effect is checked to be qualified, the nut 2 is removed, and the corrosion protection treatment is performed on the tail of the anchor rod, so that the anchor rod is implemented.
Specific data values of the examples are as follows:
example 1
When the water-solid ratio of the slurry was 0.4, the fine particles consisted of 20% alkaline excited material and 80% industrial solid waste (wherein the alkaline excited material consisted of 70% light burned magnesia and 30% quicklime powder, the industrial solid waste consisted of 70% slag and 30% sludge incineration ash), the aeration pressure of the carbonized layer portion was 100kPa, the aeration time was 3 hours, the aeration pressure of the enlarged head 12 region was 200kPa, and the aeration time was 6 hours.
TABLE 1 materials and construction parameters under example 1
Remarks: p (P) 1 : a first design ventilation pressure; t (T) 1 : a first design carbonization time; p (P) 2 : a second design ventilation pressure; t (T) 2 : and designing carbonization time. The symbols in the following tables are identical in meaning.
Example 2
When the water-solid ratio of the slurry is 0.5, the fine particles are composed of 30% of an alkali-activated material and 70% of an industrial solid waste (wherein the alkali-activated material is composed of 70% of light burned magnesium oxide and 30% of quicklime powder, the industrial solid waste is composed of 70% of slag and 30% of sludge incineration ash), the aeration pressure of the carbonized layer portion is 150kPa, the aeration time is 3 hours, the aeration pressure of the enlarged head 12 region is 300kPa, and the aeration time is 6 hours.
TABLE 2 materials and construction parameters under example 2
Example 3
When the water-solid ratio of the slurry was 0.5, the fine particles consisted of 30% alkali-activated material and 70% industrial solid waste (wherein the alkali-activated material consisted of 80% light burned magnesia and 20% quicklime powder, the industrial solid waste consisted of 80% slag and 20% sludge incineration ash), the aeration pressure of the carbonized layer portion was 150kPa, the aeration time was 6 hours, the aeration pressure of the enlarged head 12 region was 300kPa, and the aeration time was 9 hours.
TABLE 3 materials and construction parameters under example 3
Example 4
When the water-solid ratio of the slurry was 0.6, the fine particles consisted of 40% alkali-activated material and 60% industrial solid waste (wherein the alkali-activated material consisted of 80% light burned magnesia and 20% quicklime powder, the industrial solid waste consisted of 80% slag and 20% sludge incineration ash), the aeration pressure of the carbonized layer portion was 150kPa, the aeration time was 9 hours, the aeration pressure of the enlarged head 12 region was 300kPa, and the aeration time was 9 hours.
TABLE 4 materials and construction parameters under example 4
Example 5
When the water-solid ratio of the slurry was 0.7, the fine particles consisted of 50% of an alkali-activated material and 50% of an industrial solid waste (wherein the alkali-activated material consisted of 100% of light burned magnesium oxide and 0% of quicklime powder, and the industrial solid waste consisted of 85% of slag and 15% of sludge incineration ash), the aeration pressure of the carbonized layer portion was 200kPa, the aeration time was 12 hours, the aeration pressure of the enlarged head 12 region was 400kPa, and the aeration time was 12 hours.
TABLE 5 materials and construction parameters under example 5
The above-described embodiments are merely for illustrating and explaining the technical solution and are not limiting in this respect, and it should be understood by those skilled in the art that the technical solution of the present invention may be modified or equally substituted; the scope of the claims should be covered without departing from the spirit and scope of the invention.
Claims (2)
1. A method for constructing a prestressed anchor rod carbonized by magnesium oxide-carbon dioxide, which is characterized by comprising the following steps:
a. paying-off positioning: determining the position, the distance, the depth, the diameter and the inclination angle of the anchor rod holes according to the investigation data and the design file, determining the depth, the length and the diameter of the variable section of the anchor rod, and paying off on the slope surface;
b. hole digging and hole cleaning: according to the anchor rod parameters determined by paying off positioning, rotary drilling is carried out to a designed depth by using an anchor rod drilling machine, the rotary diameter of a drill bit of the drilling machine is adjusted at the designed variable cross section position and the bottom, an anchor rod hole with the variable cross section and an enlarged head is formed by rotary drilling, and finally the anchor rod hole is cleaned by using a high-pressure air gun;
c. implanting an anchor rod: implanting a qualified anchor rod into the anchor rod hole, finely adjusting the anchor rod to enable a telescopic carbonizer of the anchor rod to be aligned with the variable cross section of the anchor rod hole, and then screwing a nut to fix the air injection channel A;
the anchor rod comprises an air injection hole A, an air injection hole B, a nut, an air injection channel A, an air injection channel B, a telescopic carbonizer, a sleeve, an expansion head, an grouting channel, an air injection hole area C, an air injection hole area A and an air injection hole area B; the gas injection hole areas B are annular, the gas injection hole areas B are arranged on the side face of the gas injection channel B at intervals, telescopic carbonizers are arranged between the adjacent gas injection hole areas B, each telescopic carbonizer comprises a carbonizer head, a gas injection hole area C, a limiting cylinder, a lifting disc B, a spring B and a gas injection channel C, one end of the gas injection channel C is communicated with the gas injection channel B, the other end of the gas injection channel C is communicated with the carbonizer head, and the gas injection hole area C is arranged on the carbonizer head; the air injection channel A is fixedly connected with the lifting disk A, the air injection channel B is fixedly connected with the limiting disk, the lifting disk A is connected with the limiting disk through a spring A, and the relative displacement between the lifting disk A and the limiting disk is limited by a nut;
d. pulling out a cylinder for grouting: closing the gas injection hole A and the gas injection hole B, connecting a grouting pump with the upper end of a grouting channel on the sleeve, starting the grouting pump, adjusting grouting pressure, spraying slurry from the lower end of the grouting channel in the wall of the sleeve, rotating the sleeve and pulling out the sleeve after the slurry in the enlarged head is filled, continuously injecting the slurry into a carbonization layer area outside the anchor rod, synchronously injecting the slurry and pulling out the sleeve, and closing the grouting pump when the slurry fills the carbonization layer area outside the anchor rod and the sleeve is completely pulled out, so as to finish cylinder pulling grouting;
the slurry consists of fine granules with the average particle size smaller than 1mm, water and a water reducing agent, wherein the fine granules consist of alkaline gel excitation materials and industrial solid waste, the alkaline gel excitation materials consist of light burned magnesium oxide and quicklime powder, and the industrial solid waste consists of slag powder and sludge incineration ash; the water-solid ratio of the slurry is 0.4-0.7, and the higher the content of the alkaline material is, the larger the water-solid ratio is; the alkaline gel excitation material and the industrial solid waste respectively account for 20-50% and 50-80% of the fine granules, the light burned magnesia and the quicklime powder respectively account for 70-100% and 0-30% of the alkaline gel excitation material, and the slag powder and the sludge incineration ash respectively account for 70-85% and 15-30% of the industrial solid waste;
e. gas injection carbonization: CO is processed by 2 The high-pressure gas tank is connected with the gas injection hole B, a ventilation valve B on the gas injection hole B is opened, and the ventilation pressure is regulated to a first design ventilation pressure, so that CO 2 The gas diffuses to the carbonization layer area through a gas injection hole area B and a telescopic carbonizer on the gas injection channel B, and after the gas is aerated and maintained for a first designed carbonization time, the breather valve B is closed to finish gas injection carbonization of the carbonization layer;
the CO 2 Collecting compressed high pressure CO from high carbon emission coal and cement plants 2 CO used 2 The concentration is greater than 40%, the first design ventilation pressure is 100-200 kPa, the first design carbonization time is 3-12 hours, the first design ventilation pressure and the first design carbonization time are determined according to the thickness of the carbonization layer, and the thicker the carbonization layer is, the greater the first design ventilation pressure and the first design carbonization time are;
f. and (3) applying prestress: the position of a lifting disk A fixedly connected with the air injection channel A is adjusted through a rotating nut, so that the designed prestress is achieved;
g. carbonization enlarged head region: CO is processed by 2 The high-pressure air tank is connected with the air injection hole A, a ventilation valve A on the air injection hole A is opened, and the ventilation pressure is regulated to a second design ventilation pressure to enable CO to be discharged 2 The gas is diffused to the expansion head area through the gas injection hole area A of the gas injection channel A, and after ventilation maintenance is carried out until the second designed carbonization time, the ventilation valve A is closed to finish gas injection carbonization of the expansion head area;
the second design ventilation pressure is 200-400 kPa, the second design carbonization time is 6-12 hours, the second design ventilation pressure and the second design carbonization time are determined according to the length of the anchor rod and the diameter of the enlarged head, and the larger the length of the anchor rod and the diameter of the enlarged head, the larger the second design ventilation pressure and the second design carbonization time;
h. and (3) performing construction ending: unloading the vent valve A, enabling the micro detector to enter from the gas injection hole A, advancing inwards at a constant speed along the gas injection channel A, checking carbonization reinforcing effects of the carbonization layer and the enlarged head area in the advancing process, and performing secondary carbonization treatment on the unqualified area if the carbonization layer and the enlarged head area are unqualified; and when the test is qualified, the nut is removed, and the tail of the anchor rod is subjected to corrosion protection treatment, so that the anchor rod is finished.
2. The method for applying the prestress anchor rod carbonized by magnesium oxide-carbon dioxide according to claim 1, wherein the sleeve is made of hard plastic or stainless steel with the diameter of 100-300mm, the sleeve is pulled out to rotate alternately clockwise and anticlockwise, and the pulled sleeve can be recycled; the grouting channels are uniformly distributed in the wall of the sleeve, the inner diameter of each grouting channel is smaller than the wall thickness of the sleeve, the number of the grouting channels is 3-12 according to the diameter of the sleeve, and the larger the diameter of the sleeve is, the more the number of the grouting channels is.
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| CN107100656B (en) * | 2017-07-10 | 2019-02-05 | 中南大学 | A kind of anti-reflection slip casting Composite Bolt method for protecting support of liquid carbon dioxide explosion |
| CN110117957A (en) * | 2019-03-29 | 2019-08-13 | 武大巨成结构股份有限公司 | A kind of installation method of concrete hollow anchor pole tooling |
| CN110512603B (en) * | 2019-08-20 | 2021-02-09 | 湖北省地质勘察基础工程有限公司 | Prestressed anchor rod capable of secondary grouting and method |
| CN110512592B (en) * | 2019-09-02 | 2021-05-18 | 南京林业大学 | Vacuum preloading and guide pipe pile gas injection carbonization ultra-soft foundation reinforcement processing system |
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