CN115262626A - Construction method of underground space prestress steel reinforced concrete top cover under super-large span heavy load - Google Patents
Construction method of underground space prestress steel reinforced concrete top cover under super-large span heavy load Download PDFInfo
- Publication number
- CN115262626A CN115262626A CN202210723018.9A CN202210723018A CN115262626A CN 115262626 A CN115262626 A CN 115262626A CN 202210723018 A CN202210723018 A CN 202210723018A CN 115262626 A CN115262626 A CN 115262626A
- Authority
- CN
- China
- Prior art keywords
- steel
- prestressed
- concrete
- plate
- reinforcing
- 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.)
- Granted
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 200
- 239000010959 steel Substances 0.000 title claims abstract description 200
- 238000010276 construction Methods 0.000 title claims abstract description 48
- 239000011150 reinforced concrete Substances 0.000 title claims abstract description 31
- 239000004567 concrete Substances 0.000 claims abstract description 65
- 230000003014 reinforcing effect Effects 0.000 claims abstract description 43
- 238000000034 method Methods 0.000 claims abstract description 25
- 238000005520 cutting process Methods 0.000 claims abstract description 11
- 238000004873 anchoring Methods 0.000 claims abstract description 9
- 230000002787 reinforcement Effects 0.000 claims description 35
- 229910001294 Reinforcing steel Inorganic materials 0.000 claims description 33
- 239000004568 cement Substances 0.000 claims description 26
- 239000011148 porous material Substances 0.000 claims description 20
- 239000002002 slurry Substances 0.000 claims description 17
- 238000003466 welding Methods 0.000 claims description 15
- 238000013461 design Methods 0.000 claims description 14
- 210000001503 joint Anatomy 0.000 claims description 13
- 238000012360 testing method Methods 0.000 claims description 13
- 239000011440 grout Substances 0.000 claims description 12
- 239000011241 protective layer Substances 0.000 claims description 12
- 238000009434 installation Methods 0.000 claims description 8
- 239000003795 chemical substances by application Substances 0.000 claims description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 7
- 230000000740 bleeding effect Effects 0.000 claims description 6
- 239000002023 wood Substances 0.000 claims description 6
- 238000007667 floating Methods 0.000 claims description 4
- 238000012423 maintenance Methods 0.000 claims description 4
- 239000004570 mortar (masonry) Substances 0.000 claims description 4
- 238000007664 blowing Methods 0.000 claims description 3
- 239000003638 chemical reducing agent Substances 0.000 claims description 3
- 239000004746 geotextile Substances 0.000 claims description 3
- 239000011521 glass Substances 0.000 claims description 3
- 239000011248 coating agent Substances 0.000 claims description 2
- 238000000576 coating method Methods 0.000 claims description 2
- 238000011010 flushing procedure Methods 0.000 claims description 2
- 230000000149 penetrating effect Effects 0.000 claims description 2
- 238000009417 prefabrication Methods 0.000 claims description 2
- 210000002435 tendon Anatomy 0.000 claims description 2
- 239000000463 material Substances 0.000 abstract description 4
- 239000011513 prestressed concrete Substances 0.000 abstract description 4
- 238000007789 sealing Methods 0.000 abstract description 4
- 238000007689 inspection Methods 0.000 description 11
- 238000005336 cracking Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000004575 stone Substances 0.000 description 5
- 230000002159 abnormal effect Effects 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- 238000012797 qualification Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000012937 correction Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 239000004033 plastic Substances 0.000 description 2
- 238000003825 pressing Methods 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 239000005662 Paraffin oil Substances 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000033228 biological regulation Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 239000011083 cement mortar Substances 0.000 description 1
- 230000009193 crawling Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 239000002283 diesel fuel Substances 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 238000009415 formwork Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 238000011900 installation process Methods 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 230000009191 jumping Effects 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 238000002372 labelling Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000010907 mechanical stirring Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000012945 sealing adhesive Substances 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D29/00—Independent underground or underwater structures; Retaining walls
- E02D29/045—Underground structures, e.g. tunnels or galleries, built in the open air or by methods involving disturbance of the ground surface all along the location line; Methods of making them
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D15/00—Handling building or like materials for hydraulic engineering or foundations
- E02D15/02—Handling of bulk concrete specially for foundation or hydraulic engineering purposes
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Civil Engineering (AREA)
- Environmental & Geological Engineering (AREA)
- Manufacturing Of Tubular Articles Or Embedded Moulded Articles (AREA)
- Reinforcement Elements For Buildings (AREA)
Abstract
The invention relates to the technical field of underground engineering, in particular to a construction method of a prestressed steel reinforced concrete top cover of an underground space under an ultra-large span heavy load, which comprises the following steps: the method comprises the following steps of material blanking and entering, bottom die laying, plate bottom reinforcing mesh binding, profile steel hoisting and positioning, reinforcing cage binding, corrugated pipe positioning, side die supporting, plate top reinforcing mesh binding, concrete pouring, prestressed rib tensioning and anchoring, corrugated pipe grouting and cutting and sealing. When the construction method is adopted to carry out the construction of the prestressed steel concrete top cover, the construction efficiency can be effectively improved, the engineering quality is ensured, and the manufactured prestressed steel concrete top cover combines the characteristics of high bearing capacity, large rigidity and light dead weight of a steel concrete structure and the characteristic of good crack resistance and deformation resistance of the prestressed concrete structure, can improve the crack resistance and deformation resistance of the whole top cover, and can be widely applied to the field of the construction of the prestressed steel concrete top cover.
Description
Technical Field
The invention relates to the technical field of underground engineering, in particular to a construction method of a prestressed steel reinforced concrete top cover of an underground space with an ultra-large span and heavy load, which can be used for underground structures, basements and other structural engineering of rail transit engineering.
Background
Along with the development of urban underground construction, the demand of underground super-large span space structures is increasingly increased, and meanwhile, the design and construction of the super-large span underground space structures are difficult due to higher load on the upper parts of the structures. The common structural form in the prior engineering, such as a densely-arranged rib beam structure, can reduce the use height of the structure, the construction is complex, the construction efficiency is low, and the crack width in the midspan and the support is difficult to control; the folded plate and the arch structure can cause large horizontal force, and the Y-shaped column structure has limitation on the clearance and the use function of the structure.
Therefore, it is necessary to design a construction method of the prestressed steel reinforced concrete top cover of the underground space under the ultra-large span heavy load to overcome the above problems.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention aims to provide the construction method of the prestressed steel reinforced concrete top cover of the underground space under the super-large span heavy load, which meets the clearance requirement of the underground space under the super-large span heavy load and the anti-cracking and anti-deformation requirements of the top cover, can effectively improve the construction efficiency and ensure the engineering quality.
In order to achieve the purpose, the technical scheme of the invention is a construction method of a super-large span heavy load underground space prestressed steel reinforced concrete top cover, which comprises the following steps:
1. feeding into a field: blanking section steel, reinforcing steel bars and prestressed steel strands according to a blanking list;
2. paving a bottom die;
3. and (3) binding a plate bottom reinforcing mesh: binding a plate bottom reinforcing mesh, and backing a plate bottom reinforcing protective layer cushion block;
4. hoisting and positioning the profile steel: sequentially hoisting and positioning a plurality of section steels above the slab bottom reinforcing mesh, wherein the section steels are arranged at intervals;
5. binding a reinforcement cage: binding a reinforcement cage, reserving sufficient operation space for installation of the corrugated pipe, hoisting the reinforcement cage between adjacent section steels, and connecting the reinforcement cage with a slab-bottom reinforcement mesh;
6. positioning the corrugated pipe: mounting a corrugated pipe at the designated position of the steel reinforcement cage, wherein the corrugated pipe is in a curve shape, positioning according to the curve coordinate of the prestressed steel strand in the design drawing by taking the bottom of the corrugated pipe as a reference, calibrating the elevation and the horizontal verticality, and then fixing the corrugated pipe;
7. a side mould is supported;
8. and (3) binding a steel bar mesh on the plate top: binding a plate top reinforcing mesh, and connecting the plate top reinforcing mesh with a reinforcement cage;
9. pouring concrete: pouring concrete and curing the concrete;
10. tensioning and anchoring the prestressed tendons: after the strength of the concrete reaches a certain strength, the side mold is disassembled; penetrating the prestressed steel strands into corresponding corrugated pipes according to the serial numbers, performing prestressed tensioning operation by adopting tensioning equipment, and anchoring after the prestressed steel strands are tensioned;
11. grouting the corrugated pipe: flushing the corrugated pipe, blowing out accumulated water in the pore channel, and grouting the pore channel;
12. and cutting the seal anchor.
Further, in the second step, the bottom die is cast by adopting concrete not smaller than C30, the thickness of the bottom die is not smaller than 30 cm, a steel plate with the thickness of 3 mm is paved on the bottom die, and a PVC plate with the thickness of 2 mm is adhered on the steel plate; rubber strips are arranged on the contact surfaces of the two sides of the bottom die and the side die, the rubber strips are flush with the top surface of the bottom die, and the joints are smooth; and after the surface of the bottom die is clean and flat, uniformly coating a release agent on the surface.
Further, in the third step, a binding mold is installed according to geometric dimension lofting and steel bar position line snapping results; according to the principle of designing and placing the plate bottom reinforcing mesh, firstly paving short-direction reinforcing steel bars, then paving long-direction reinforcing steel bars, correcting the reinforcing steel bars according to the position lines of the reinforcing steel bars, and binding point by point; and (4) after the plate bottom reinforcing mesh is bound, backing a cushion block of the reinforcing layer of the bottom plate, wherein the cushion block is arranged in a quincunx shape.
Further, in the fourth step, the section steel is spliced on site by adopting factory prefabrication, the prefabricated section steel is hoisted to an accurate position and is temporarily supported and fixed, two jacks are arranged at the position of a butt joint, the verticality and the elevation are corrected by the jacks, a fixed point is welded, and then the section steel is fixed by a steel pipe fastener; and then hoisting the assembled section steel to a specified position above the plate bottom reinforcing mesh, fixing the section steel, and fixing a plurality of section steel above the plate bottom reinforcing mesh at intervals according to a design drawing.
Furthermore, in the sixth step, an n-shaped steel bar is bound to the corrugated pipe at intervals, the n-shaped steel bar and the bracket steel bar are welded firmly, and the bracket steel bar and the steel reinforcement cage are welded and fixed.
Further, in the seventh step, the side forms are assembled in sections outside the field in advance, PVC plates with the thickness of 2 mm are adhered on the surfaces of the side forms, the PVC plates are cleaned and then evenly coated with an isolating agent, the pre-assembled two side forms are connected through counter-pulling bolts which transversely penetrate through the base, and wood wedges are driven between pre-embedded ground anchors or steel bars of the bottom base and the side forms; when the side mold is provided with a bracket, the supporting legs are nailed by steel plates or wood wedges; the parts where the joints between the side mold and the bottom mold and between the side mold and the side mold are not tight are filled with putty or transparent glass cement.
Further, in the eighth step, when the plate top reinforcing mesh is bound, a reinforcing steel bar support is adopted for supporting operation, and meanwhile, the accurate position of the reinforcing steel bar of the top plate is ensured; and after the plate top reinforcing mesh is bound, arranging a cushion block of the plate top reinforcing protective layer.
Further, in the ninth step, the concrete pouring adopts one-time pouring, the pouring is uninterrupted in the construction, and the pouring is started from one end to the other end; the attached vibrator is adopted to strengthen vibration on concrete at the plate girder, the position where the reinforcing steel bars are more dense and the corrugated pipe, so that the concrete is compacted; after the concrete is poured and the slurry is collected, performing secondary plastering and slurry collection, performing napping, removing floating slurry, covering with geotextile, and performing maintenance operation; and in the concrete curing period, the concrete is ensured to be always in a wet state, concrete test pieces are left in the pouring process, at least two groups of concrete test pieces are cured under the same condition as the plate body, and the tension time is determined according to the strength of the test pieces.
Further, in the tenth step, after the strength of the concrete reaches 85% of the design strength and the age is not less than 7 days, tensioning can be performed, the prestressed steel strand bundle is symmetrically tensioned in batches at two ends, and the tensioning process is controlled to be 0-10% sigma con-20% sigma con-100% sigma con (holding load for 2 minutes) → anchoring.
Further, in the eleventh step, the cement paste used for grouting is 52.5-grade cement, the bleeding rate of the cement paste is not more than 3%, the free expansion rate is less than 10%, the consistency is 14-18 seconds, the water-cement ratio is 0.4-0.45, and if a water reducing agent is doped, the water-cement ratio is not less than 0.35; and (3) during grouting, keeping the pump pressure of the mortar pump at 0.5-0.7 MPa, closing a grout outlet valve when thick grout is discharged from the other end, increasing the pressure to 0.7 MPa, keeping the pressure for 2 minutes, and closing a grouting nozzle valve at the grouting end.
Compared with the prior art, the invention has the following beneficial effects:
(1) When the construction method is used for constructing the prestressed steel reinforced concrete top cover, the construction efficiency can be effectively improved, the engineering quality is ensured, and the construction method can be widely applied to the field of prestressed steel reinforced concrete top cover construction.
(2) The prestressed steel reinforced concrete top cover disclosed by the invention combines the characteristics of high bearing capacity, high rigidity and light dead weight of a steel reinforced concrete structure and the characteristics of good crack resistance and deformation resistance of the prestressed concrete structure, can improve the crack resistance and deformation resistance of the integral top cover, and effectively meets the requirements of large span, section size and earthquake resistance of the structure under the action of heavy load.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a perspective view of a prestressed steel reinforced concrete roof of an underground space under an ultra-large span heavy load (when the section steel is an I-shaped steel) provided by an embodiment of the invention;
fig. 2 is a schematic view of a corrugated pipe in a reinforcement cage framework according to an embodiment of the present invention;
FIG. 3 is a schematic cross-sectional view of two ends of a prestressed steel reinforced concrete top cover of an underground space under a super-large span heavy load according to an embodiment of the present invention (when the steel section is an I-shaped steel);
FIG. 4 is a schematic cross-sectional view of a middle span of a prestressed steel reinforced concrete top cover of an underground space under a heavy load of an ultra-large span provided by an embodiment of the invention (when the section steel is I-shaped steel);
FIG. 5 is a schematic cross-sectional view of a bellows according to an embodiment of the present invention;
FIG. 6 is a flow chart of a construction method of the prestressed steel reinforced concrete roof of the underground space under the ultra-large span heavy load according to the embodiment of the invention;
in the figure: 1. a prestressed steel reinforced concrete top cover; 2. section steel; 3. a bellows; 4. plate top reinforcing mesh; 5. a mat bottom reinforcing mesh; 6. longitudinal hooping; 7. constructing and erecting steel bars; 8. pre-stressed steel strands; 9. and (3) cement paste.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention. In the description of the present invention, "a number" means two or more unless otherwise specified.
As shown in fig. 1 and 6, a construction method of a prestressed steel reinforced concrete top cover 1 of an underground space under an ultra-large span heavy load comprises the following steps:
1. feeding into field
1) Blanking various materials (profile steel, reinforcing steel bars and prestressed steel strands) is strictly carried out according to a blanking list, the allowable error is within +/-0.1 meter, 1 centimeter of prestressed steel strands is less placed at intervals of 10 meters in the blanking and scale placing process, and the rest is done in the same way according to the actual length;
2) After each reinforcing steel bar, section steel or prestressed steel strand is laid in the on-site blanking process, labeling and indicating the type specification and the number of the component at the position of about 20 cm from the end part immediately, stacking each type of component in a classified manner according to the number after blanking is finished, and intensively placing each type of component and marking by standing the plate;
3) All components need to be batched according to the regulations of the current national standard or industry standard, the steel bars need to be provided with steel bar delivery qualification certificates and mechanical property field sampling inspection report sheets, the section steel should be provided with section steel delivery inspection reports, qualification certificates and material quality certification documents, the steel strands and other materials should be provided with delivery qualification certificates and mechanical property field sampling inspection reports and the like;
2. bottom die laying
1) The top cover bottom die is cast by adopting concrete not less than C30, the thickness is not less than 30 cm, a steel plate with the thickness of 3 mm is paved, and all indexes meet the standard requirements through stress checking calculation;
2) After the surface of the steel plate is cleaned, a PVC plate with the thickness of 2 mm is adhered on the steel plate; then rubber strips are arranged on the contact surfaces of the two sides of the bottom die and the side die to prevent slurry leakage, the rubber strips are parallel to the top surface of the bottom die, and the joint seam is smooth; cleaning the bottom die, wherein the surface of the bottom die is free of residues, smooth in line shape and flat in surface, and a release agent is uniformly coated on the surface of the bottom die; lofting is carried out according to the geometric dimension of the plate, and the elastic line of the bottom die is marked;
3. plate bottom reinforcing mesh binding
1) Mounting a binding mold according to the geometric dimension lofting and the steel bar position line snapping result; according to the principle of designing and placing the reinforcing steel bars of the bottom plate, firstly paving the short-direction reinforcing steel bars, then paving the long-direction reinforcing steel bars (the short-direction reinforcing steel bars are arranged at the lower part, and the long-direction reinforcing steel bars are arranged at the upper part), correcting the reinforcing steel bars according to the position lines of the reinforcing steel bars and binding the reinforcing steel bars point by point;
2) After the bottom reinforcing mesh is bound, backing a bottom plate reinforcing layer cushion block, wherein the side surface protective layer of the plate bottom reinforcing mesh 5 is 50 mm thick, a 50X 50 mm fine stone concrete (C20) cushion block is adopted, the quincunx arrangement @1000 is adopted, and a No. 22 firing wire is pre-buried on the protective layer cushion block; and the fine stone concrete cushion block needs to be reinforced and maintained during manufacturing so as to ensure the strength of the cushion block;
3) After the plate bottom reinforcing mesh 5 is finished, the thickness of a reinforcing steel bar protective layer is checked, and the phenomenon of bar exposure caused by the fact that reinforcing steel bars are close to a template is avoided;
4. shaped steel hoist and mount location
1) The section steel 2 is prefabricated in a factory and spliced on site, the section steel is manufactured in a section, processed and transported in the factory, and the section steel is integrally hoisted after being spliced on site; the section steel 2 adopts I-shaped steel or box-shaped steel, so that the characteristics of high strength and high rigidity of a section steel concrete structure can be utilized, the self weight of a plate body is reduced, the steel is saved, and the upper flange plate and the lower flange plate of the section steel 2 are symmetrically welded with a plurality of studs, so that the adhesive force and the shearing resistance of the section steel 2 and the concrete are improved, as shown in the figures 3 and 4; two jacks are arranged at the joint positions of the section steel, so that the splicing and the correction are convenient,
2) The prefabricated section steel needs quality inspection records and product certificates, the shape size, the diameter and the position of a reserved hole, the position and the angle of a connecting piece, a welding line, the processing quality of stud welding and the like need to be comprehensively inspected before installation, and the prefabricated section steel can meet design documents and relevant standards.
3) Hoisting the prefabricated section steel to an accurate position, temporarily supporting and fixing, correcting perpendicularity and elevation through a jack and the like, welding a fixed point, fixing through a steel pipe fastener, supporting a template by adopting a fastener steel pipe type scaffold supporting system, fixing a transverse steel pipe of a bottom template of a supporting beam according to the elevation of the bottom of the beam during template assembly, enabling the template to meet design requirements according to the axis size and the section width, and fixing through the steel pipe fastener after the template is subjected to bracing wire correction and acceptance;
4) Hoisting the assembled section steel to a specified position above the slab bottom reinforcing mesh 5 and fixing, and fixing a plurality of section steel above the slab bottom reinforcing mesh 5 at intervals according to a design drawing;
5. binding of reinforcement cage
1) The steel reinforcement cage process adopts on-site manufacture, binding and hoisting; the reinforcement cage comprises a plurality of longitudinal stirrups 6 and a plurality of constructional erection reinforcements 7, as shown in fig. 1 and 2, the longitudinal stirrups 6 are arranged at intervals among the section steels 3, and the constructional erection reinforcements 7 penetrate through the longitudinal stirrups 6 and are connected with each other; the longitudinal stirrups 6 and the structural erection steel bars 7 are reasonably arranged by considering the position of the concrete guide pipe when arranged, and sufficient operation space is reserved for the installation of the corrugated pipe 3 to ensure the smooth concrete pouring; the full welding and cross welding parts of the steel bar welding are strictly controlled according to the construction drawing, and the quality of welding spots meets the requirements of welding specifications; the length and thickness of the welding seam of the truss and the lifting ring need to meet the requirement of lifting deformation;
2) Manufacturing and binding a plurality of reinforcement cages on site, hoisting the reinforcement cages between adjacent section steels, butting the reinforcement cages with the plate bottom reinforcement mesh 5, performing on-site inspection and spot inspection on joints, positioning and fixing after the joints are inspected to be qualified, and binding and connecting the joints with the plate bottom reinforcement mesh 5; in order to ensure the integrity, the binding joint of the steel bar cage must be welded after the binding is finished so as to ensure the integrity of the steel bar cage;
6. bellows positioning
1) The corrugated pipe 3 is a metal corrugated pipe, and arc cutting cannot be adopted in installation; the corrugated pipe should be protected against moisture and rust when stored after entering a field, and the appearance should be checked before installation; the joint seam of the adjacent corrugated pipe joints is ensured to have the length not less than 30 cm and the distance between the two ends is equal, and the joint seam is sealed by applying a sealing adhesive tape and the like to prevent slurry leakage;
2) Mounting a corrugated pipe 3 at a given position of a steel reinforcement cage, wherein the corrugated pipe 3 is in a curve shape, positioning according to the curve coordinate of a prestressed steel strand 8 in a design drawing by taking the bottom of the corrugated pipe 3 as a reference, and calibrating elevation, horizontal verticality and the like; the corrugated pipe 3 is fixed through an anchor backing plate, and in order to prevent the anchor backing plate from loosening and shifting during pouring, the anchor backing plate is fixed on the end socket template through screws; in order to prevent the corrugated pipe 3 from floating upwards along with cement mortar during pouring, n-type steel bars can be tied on the corrugated pipe 3 at certain intervals, the n-type steel bars and bracket steel bars are firmly welded, the interval is generally 60 cm, and the bracket is welded on the stirrups of a steel reinforcement cage; the corrugated pipe 3 is prevented from being repeatedly bent to crack the pipe wall in the installation process, so that the construction quality is not influenced; during welding, a precaution shield is required to be well taken, so that the wall of the pipe is prevented from being burnt by electric welding sparks; a plurality of corrugated pipes 3 can be fixed in the reinforcement cage between adjacent section steels at intervals, and as shown in fig. 2-4, the specific number can be determined according to actual conditions;
3) In order to ensure the compactness of the pipeline after grouting, the corrugated pipe is provided with a grouting hole, an exhaust hole and a bleeding hole, the peak part of a curved pore passage is provided with the exhaust hole, and the lowest part is provided with the drain hole; when the anchor backing plate is installed, one end of the same pore channel is placed below the grouting hole and used as the grouting hole, and the other end of the same pore channel is placed above the exhaust hole and the bleeding hole and used for exhausting and bleeding; after the concrete of the plate body is poured, cleaning holes of the corrugated pipe by using an air compressor, and timely cleaning when the holes are found to be blocked;
7. side form support
1) The side forms are assembled in sections outside the field in advance, PVC plates with the thickness of 2 mm are adhered to the surfaces of the side forms, after the side forms are cleaned, an isolating agent is uniformly coated on the surfaces of the side forms, the pre-assembled two side forms are connected through counter-pulling bolts crossing the base, and wood wedges are driven between ground anchors or reinforcing steel bars embedded in the bottom form in advance and the side forms; when the side mold is provided with a bracket, the supporting legs are nailed by steel plates or wood wedges;
2) The template has smooth and tight joints without staggered platforms, the length, width and height dimensions in the template meet the requirements of design drawings and construction specifications, the counter-pulling screw rods are complete and tightly pulled, and the support is stable; the parts where joints between the side mold and the bottom mold and between the side mold and the side mold are not tight are filled with atomic ash or transparent glass cement, so that the joints of the template are ensured not to leak slurry;
8. binding of plate top reinforcing mesh
1) The plate top reinforcing mesh 4 adopts a reinforcing steel bar bracket to carry out supporting operation during binding construction, and meanwhile, the position accuracy of the reinforcing steel bar of the top plate is ensured; the steel bar supports are arranged according to construction drawings and construction schemes strictly in the using and installing process, and the steel bar supports with different forms and heights cannot be used together, so that the accuracy of the positions of the steel bars is ensured;
2) After the plate top reinforcing mesh 4 is bound, manufacturing a cushion block of a protective layer on the side surface of the plate top; the protective layer on the side face of the reinforcing mesh is 50 mm thick, 50 x 50 mm fine stone concrete (C20) cushion blocks are adopted, the @1000 quincunx arrangement is adopted, 22# flame-cured wires are pre-embedded on the protective layer cushion blocks, and the fine stone concrete cushion blocks need to be reinforced and maintained to ensure the strength of the fine stone concrete cushion blocks during manufacturing;
9. pouring of concrete
1) The concrete construction is carried out on the side mold, the bottom plate steel bar, the steel reinforcement cage binding, the profile steel installation, the prestressed pipeline and the plate top steel bar binding, and can be poured after the self-inspection and the spot inspection are qualified through the inspection of hidden engineering; pouring is performed at one time, the construction is uninterrupted, and the pouring is started from one end to the other end;
2) The mixing proportion and the slump of the concrete are strictly controlled in the concrete pouring process, the concrete which cannot meet the construction requirements cannot be used, and the appearance quality of the concrete is ensured;
3) An attached vibrator is adopted when concrete is vibrated, a 50-type inserted vibrator is adopted when a plate girder is vibrated, and a 30-type inserted vibrator is adopted at a position where reinforcing steel bars are dense to enhance vibration, so that the compactness of concrete under an anchor is ensured;
4) The concrete is not easy to fall at the prestressed corrugated pipe, the concrete is conveyed to the corrugated pipe by adopting a 30-type inserted vibrating rod, so that the corrugated pipe is filled with the concrete, the positioning of the corrugated pipe, the profile steel, the reinforcement cage and the reinforcement mesh is monitored at any time in the concrete pouring construction process, and if the pipeline deviation is found, the pipeline deviation is adjusted in time;
5) After concrete pouring is finished and slurry is collected, secondary plastering and slurry collection are carried out to avoid local cracking, napping is carried out, floating slurry is removed, and finally, geotextile is used for covering, and maintenance operation is carried out at the same time;
6) Arranging a formwork worker and a reinforcement worker on duty in the concrete pouring process, timely handling problems in construction, and simultaneously drawing the plastic lining pipe in the pipeline once every 15 m to prevent the corrugated pipe from leaking slurry and blocking the prestressed pipeline;
7) In the concrete curing period, the concrete is ensured to be always in a wet state, concrete test pieces are left in the pouring process, at least two groups of concrete test pieces are cured under the same condition as the plate body, and the tension time is determined according to the strength of the test pieces;
10. prestressed reinforcement stretch-draw anchor
1) Calibrating the tensioning equipment before tensioning the prestressed steel strand 8, wherein all the tensioning equipment is calibrated and maintained at least every six months or 200 times; in the use process, if abnormal conditions occur, the tensioning equipment must be calibrated again; when the strength of the concrete reaches 85% of the designed strength and the age is not less than 7 days, tensioning can be carried out, before tensioning is started, all prestressed steel strands can freely move between tensioning points, and meanwhile, the member can freely adapt to horizontal and vertical movements of the prestressed steel strands generated when prestress is applied;
2) The calculation of the tension control stress is detailed in the design specification JGJ 369-2016 of prestressed concrete structures, the prestressed steel strand bundle is symmetrically tensioned in batches at two ends, and the tension process is controlled to be 0-10% of sigma con-20% of sigma con-100% of sigma con (holding load for 2 minutes); the prestress tensioning adopts double control of tensioning force and elongation, the error between the calculated elongation and the measured elongation is required to be within +/-6 percent, the tensioning is stopped when the error exceeds the tolerance, the reason is analyzed, and measures are taken; in the tensioning process, an operator needs to keep contact to ensure that the tension force difference is within a reasonable range, and the elongation is measured in time in the tensioning process and is compared with a theoretical calculated value;
3) The tensioning process is as follows:
(a) Sleeving a jack into the prestressed steel strand bundle, installing a tool anchor and a tool clamping piece, and lightly knocking by a hand hammer or a sleeve pipe manually to clamp the prestressed steel strand;
(b) Four persons are provided with a set of tensioning jacks, one person is responsible for an oil pump, two persons are responsible for the jacks, one person observes and records the reading, tensioning is carried out according to the design requirement sequence, and symmetrical tensioning is guaranteed;
(c) Starting a high-pressure oil pump, recording the elongation reading of the jack when the stress reaches 10 percent; attention needs to be paid to the fact that the surface of a supporting foot of the jack is in full contact with the anchor plate, each prestressed steel strand in the steel bundle needs to be stressed uniformly, and stretching is continued until 20% of initial stress is reached, and the extension reading of the jack is recorded;
(d) Continuing to stretch until the steel wire bundle is under the control stress, keeping the load for 2 minutes and recording the reading of the jack at the moment; calculating the actually measured elongation of the steel wire bundle, comparing the actually measured elongation with a theoretical value, stopping tensioning if the actually measured elongation exceeds +/-6%, and analyzing reasons;
(e) The oil cylinder slowly returns oil to enable the working clamping piece to automatically anchor the steel strand;
(f) After oil return is finished, the oil pump is closed, and the jack is dismantled;
4) The tension process considerations are as follows:
(a) Cutting the prestressed steel strand by adopting a grinding wheel saw, wherein a saw blade of the grinding wheel saw is enhanced to prevent the saw blade from flying out and hurting people, and cutting the prestressed steel strand or a corrugated pipe which penetrates into the prestressed steel strand by using gas cutting is strictly forbidden;
(b) Arranging full-time personnel to properly keep after the prestressed steel strand enters a field, avoiding corrosion, particularly ensuring that two ends of tensioning and anchoring are clean and clean, and if a corrosion pit reducing the strength and the elongation rate is formed on the surface of the prestressed steel strand, the prestressed steel strand cannot be used;
(c) The working length of the prestressed steel strand is determined according to the type of the tensioning jack;
(d) Strictly moving the box girder before pore canal grouting;
(e) Tensioning irrelevant personnel are strictly prohibited to enter a tensioning site; during tensioning, people cannot stand behind the jack, so that the prestressed steel strands are prevented from being broken or the pins are popped out to hurt people; when the high-pressure oil pump has abnormal conditions, the high-pressure oil pump should be immediately stopped for inspection;
(f) The oil meter and jack should be checked in a matched manner under the following conditions:
a. one of the jack and the oil meter is used for the first time or continuously used for six months after entering the field, and continuously tensioned for 200 times;
b. when the transportation and tension operation is abnormal;
c. the oil meter is violently vibrated, the pointer cannot return to zero, and the reading error is generated;
d. after the jack leaks oil or is repaired;
(g) The anchorage device can be used only after a strict inspection test, and is cleaned piece by kerosene or diesel oil before being used, so that scrap iron, silt and oil dirt cannot be left on the surface;
(h) The jack is installed without pushing and pulling the oil pipe and the joint, the oil pipe is not twisted so as to prolong the service life, the prestressed steel strand is straightened in the jack through hole, dirt cannot be generated in the anchor conical hole, and paraffin oil is uniformly coated on the conical surfaces of the anchor and the clamping piece so as to prevent wire slipping;
(i) Tensioning operators can operate on duty after being trained and certified, before tensioning, the tensioning equipment needs to be noticed whether the check record is complete, correct or not and whether the record is abnormal or not, whether the theoretical oil pressure is correct or not and oil leakage cannot occur in an oil way or not, all valves work normally, the circuit is good in insulation, a jack, an anchorage device, a clamp and a top press are well aligned, and a dangerous area behind the jack prohibits the retention and the passing of the operators;
(j) Before tensioning operation, a jack which is parked for a long time or a jack which replaces an oil pipe needs to run back and forth for more than three times at 1/8-7/8 of the stroke, so that air in the jack can be removed until no crawling or jumping occurs, and tensioning can be carried out;
5) The surface of an anchor backing plate needs to be cleaned before the prestressed steel strands 8 are anchored, an anchorage device is sleeved on the prestressed steel strand bundle during installation, the prestressed steel strands 8 penetrate into corresponding anchor holes according to numbers, a plurality of prestressed steel strands 8 are arranged in each corrugated pipe, as shown in figure 5, the anti-cracking capacity of the top cover is improved, the prestressed steel strands 8 are arranged in a curve shape, the prestressed steel strands at the midspan position are positioned at the lower part, the prestressed steel strands at the branch points at the two ends are positioned at the upper part, different prestress at different positions of the top cover are reasonably resisted, and cracking is avoided; sequentially embedding the cleaned clamping pieces around the anchor hole steel strand, and after the clamping pieces are embedded, lightly knocking by a hand hammer or a sleeve pipe manually to clamp the prestressed steel strand, wherein the exposed lengths of the clamping pieces are neat and consistent;
11. corrugated pipe grouting
1) After the prestressed steel strand is tensioned, the prestressed steel strand is stopped for 12 hours, the anchoring condition of the steel strand is observed, then pore grouting is carried out, the steel strand is cut by a grinding wheel saw and cannot be cut by electric welding and the like, the steel strand is prevented from being scattered and ejected out of welding slag to hurt people, the length of the steel strand is left to be 30 mm, the anchor head is blocked by anchor sealing cement, and the anchor head is bound by plastic cloth to keep the anchor sealing cement wet-cured;
2) Before grouting, whether the pore passage is smooth and clean is checked; washing the pore channel by using a high-pressure water pipe to moisten the pore wall, and blowing out accumulated water in the pore channel by using an air compressor after washing; the cement paste 9 is prepared by mechanical stirring, 52.5-grade cement is adopted, the bleeding rate of the cement paste 9 is not more than 3%, the free expansion rate is less than 10%, the consistency is between 14 and 18 seconds, the water-cement ratio is between 0.4 and 0.45, and if a water reducing agent is doped, the water-cement ratio is not less than 0.35; a 1725 ml funnel is prepared on site to be used for a funnel test at any time, the cement consumption of one test is at least 4 bags (50 kg/bag), after the cement is mixed, the cement passes through a 3 mm screen and is put into a slurry storage container, the duration from self-regulation to pressing into a pore channel does not exceed 45 minutes, and the stirring is not stopped in the slurry pressing process;
3) The grouting adopts a piston type mortar pump to perform grouting, the grouting pump is firstly tried out once before grouting, and the grouting can be formally performed only when the operation is normal and the required pressure can be reached; during grouting, the pump pressure of a mortar pump is kept at 0.5-0.7 MPa, special grouting nozzles are needed to be adopted at two ends of a pore passage to ensure that the pore passage can be freely opened and closed, when thick slurry is discharged from the other end of the pore passage, a slurry outlet valve is closed, the pressure is raised to 0.7 MPa, the pressure is maintained for 2 minutes, and a grouting end grouting nozzle valve is closed; grouting of each pore channel is finished once, the grouting cannot be stopped midway, and a nozzle cannot leave a grouting hole, so that air can not enter the pore channel to form bubbles;
the grouting process notes are as follows:
(a) The pressure gauge needs to be corrected before use, all equipment is cleaned at least once every three hours in the operation process, and the equipment also needs to be cleaned when the equipment is used up on the day;
(b) The pore canal grouting is performed from bottom to top;
(c) In order to ensure that the steel bundle pipeline is completely filled with the grout, the grout inlet and the grout outlet can be sealed when the grout is pressed until the grout flows out of the grout outlet for a period of time and the concentration of the grout is consistent with that of the grout in the stirring pot;
(d) Adding an expanding agent into the grouting to ensure the compactness of the interior of the pipeline, and carrying out the next process after the cement paste reaches a certain strength after the grouting is finished;
(e) In the grouting process and within 48 hours after grouting, the temperature of the structural concrete is not lower than 5 ℃, and when the air temperature is higher than 35 ℃, grouting should be carried out in the morning and at the evening;
(f) Not less than 3 groups of standard cubic test pieces should be reserved for each working class, and the strength of standard maintenance for 28 days is used as the basis for evaluating the quality of cement paste;
12. cutting seal anchor
After the prestressed steel strand is tensioned, anchor sealing work is needed to be done, the redundant length of the prestressed steel strand is cut off, the exposed length of an anchor clamping piece is not less than 30 mm, oxygen cutting or mechanical cutting is adopted during cutting, the tensioning end and the periphery of the tensioning end are cleaned up, members are poured and filled with equal-strength concrete, vibration is carried out to the stretching end and the periphery of the stretching end, and the thickness of the exposed steel strand protective layer is not less than 20 mm.
The prestressed steel reinforced concrete top cover of the embodiment combines the characteristics of high bearing capacity, high rigidity and light dead weight of the steel reinforced concrete structure and the characteristics of good anti-cracking and anti-deformation capacities of the prestressed concrete structure, can improve the anti-cracking performance and the anti-deformation capacity of the whole top cover, effectively solves the large-span requirement, the section size requirement and the anti-seismic requirement of the structure under the action of heavy load, can effectively improve the construction efficiency and ensure the engineering quality when the construction method of the embodiment is adopted for constructing the prestressed steel reinforced concrete top cover, and can be widely applied to the field of prestressed steel reinforced concrete top cover construction.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the scope of the present invention, which is intended to cover any modifications, equivalents, improvements, etc. within the spirit and scope of the present invention.
Claims (10)
1. A construction method of a prestressed steel reinforced concrete top cover of an underground space under an ultra-large span heavy load is characterized by comprising the following steps:
1. feeding into a field: blanking section steel, reinforcing steel bars and prestressed steel strands according to a blanking list;
2. laying a bottom die;
3. and (3) binding the steel bar mesh at the bottom of the plate: binding a plate bottom reinforcing mesh and backing a plate bottom reinforcing protective layer cushion block;
4. hoisting and positioning the section steel: sequentially hoisting and positioning a plurality of section steels above the slab bottom reinforcing mesh, wherein the section steels are arranged at intervals;
5. binding a reinforcement cage: binding a reinforcement cage, reserving sufficient operation space for installation of the corrugated pipe, hoisting the reinforcement cage between adjacent section steels, and connecting the reinforcement cage with a slab-bottom reinforcement mesh;
6. positioning the corrugated pipe: mounting a corrugated pipe at the designated position of the steel reinforcement cage, wherein the corrugated pipe is in a curve shape, positioning according to the curve coordinate of the prestressed steel strand in the design drawing by taking the bottom of the corrugated pipe as a reference, calibrating the elevation and the horizontal verticality, and then fixing the corrugated pipe;
7. a side mold is supported;
8. and (3) binding of a steel bar mesh at the top of the plate: binding a plate top reinforcing mesh, and connecting the plate top reinforcing mesh with a reinforcement cage;
9. pouring concrete: pouring concrete and curing the concrete;
10. tensioning and anchoring the prestressed tendons: after the strength of the concrete reaches a certain strength, the side mold is disassembled; penetrating the prestressed steel strands into corresponding corrugated pipes according to the serial numbers, performing prestressed tensioning operation by adopting tensioning equipment, and anchoring after the prestressed steel strands are tensioned;
11. grouting the corrugated pipe: flushing the corrugated pipe, blowing out accumulated water in the pore channel, and grouting the pore channel;
12. and cutting the seal anchor.
2. The construction method of the prestressed steel reinforced concrete roof of the underground space under the ultra-large span heavy load as recited in claim 1, characterized in that: in the second step, the bottom die is cast by adopting concrete not less than C30 and not less than 30 cm in thickness, a steel plate with the thickness of 3 mm is paved on the bottom die, and a PVC plate with the thickness of 2 mm is adhered on the steel plate; rubber strips are arranged on the contact surfaces of the two sides of the bottom die and the side die, the rubber strips are flush with the top surface of the bottom die, and the joints are smooth; and after the surface of the bottom die is clean and flat, uniformly coating a release agent on the surface.
3. The construction method of the prestressed steel reinforced concrete roof of the underground space under the ultra-large span heavy load as recited in claim 1, characterized in that: in the third step, a binding mould is installed according to geometric dimension lofting and steel bar position line snapping results; according to the principle of designing and placing the plate bottom reinforcing mesh, firstly paving short-direction reinforcing steel bars, then paving long-direction reinforcing steel bars, correcting the reinforcing steel bars according to the position lines of the reinforcing steel bars, and binding point by point; and after the plate bottom reinforcing mesh is bound, backing a cushion block of the plate bottom reinforcing protective layer, wherein the cushion block is arranged in a quincunx shape.
4. The construction method of the prestressed steel reinforced concrete roof of the underground space under the ultra-large span heavy load as recited in claim 1, wherein: in the fourth step, the section steel is spliced on site by adopting factory prefabrication, the prefabricated section steel is hoisted to an accurate position and is temporarily supported and fixed, two jacks are arranged at the position of a butt joint, the verticality and the elevation are corrected by the jacks, a fixed point is welded, and then the section steel is fixed by a steel pipe fastener; and then hoisting the assembled section steel to a specified position above the plate bottom reinforcing mesh, fixing the section steel, and fixing a plurality of section steel above the plate bottom reinforcing mesh at intervals according to a design drawing.
5. The construction method of the prestressed steel reinforced concrete roof of the underground space under the ultra-large span heavy load as recited in claim 1, wherein: and step six, binding an n-shaped steel bar on the corrugated pipe at certain intervals, firmly welding the n-shaped steel bar with the bracket steel bar, and fixedly welding the bracket steel bar with the steel reinforcement cage.
6. The construction method of the prestressed steel reinforced concrete roof of the underground space under the ultra-large span heavy load as recited in claim 1, characterized in that: step seven, the side forms are assembled in sections outside the field in advance, PVC plates with the thickness of 2 mm are adhered on the surfaces of the side forms, after the side forms are cleaned up, an isolating agent is evenly coated on the side forms, the two side forms which are assembled in advance are connected through counter-pulling bolts which transversely penetrate through the base, and wood wedges are driven between ground anchors or reinforcing steel bars which are embedded in the bottom form in advance and the side forms; when the side mold is provided with a bracket, the supporting legs are firmly nailed by steel plates or wood wedges; the parts where the joints between the side mold and the bottom mold and between the side mold and the side mold are not tight are filled with putty or transparent glass cement.
7. The construction method of the prestressed steel reinforced concrete roof of the underground space under the ultra-large span heavy load as recited in claim 1, wherein: step eight, when the plate top reinforcing mesh is bound, a reinforcing steel bar support is adopted for supporting operation, and meanwhile, the accurate position of the reinforcing steel bar of the top plate is ensured; and after the plate top reinforcing mesh is bound, arranging a cushion block of the plate top reinforcing protective layer.
8. The construction method of the prestressed steel reinforced concrete roof of the underground space under the ultra-large span heavy load as recited in claim 1, characterized in that: step nine, pouring concrete at one time, wherein the pouring is uninterrupted in the construction process, and the pouring is started from one end to the other end; the attached vibrator is adopted to strengthen vibration on concrete at the plate girder, the position where the reinforcing steel bars are more dense and the corrugated pipe, so that the concrete is compacted; after concrete pouring is finished and slurry is collected, performing secondary plastering and slurry collection, performing napping, removing floating slurry, covering with geotextile, and performing maintenance operation; and in the concrete curing period, the concrete is ensured to be always in a wet state, concrete test pieces are left in the pouring process, at least two groups of concrete test pieces are cured under the same condition as the plate body, and the tension time is determined according to the strength of the test pieces.
9. The construction method of the prestressed steel reinforced concrete roof of the underground space under the ultra-large span heavy load as recited in claim 1, characterized in that: and step ten, tensioning can be carried out after the concrete strength reaches 85% of the designed strength and the age is not less than 7 days, the prestressed steel strand bundle is tensioned in batches by adopting two symmetrical ends, and the tensioning process is controlled to be 0-10% sigma con-20% sigma con-100% sigma con (holding load for 2 minutes) → anchoring.
10. The construction method of the prestressed steel reinforced concrete roof of the underground space under the ultra-large span heavy load as recited in claim 1, characterized in that: in the eleventh step, the cement paste used for grouting adopts 52.5-grade cement, the bleeding rate of the cement paste is not more than 3%, the free expansion rate is less than 10%, the consistency is 14-18 seconds, the water-cement ratio is 0.4-0.45, and if a water reducing agent is doped, the water-cement ratio is not less than 0.35; and (3) during grouting, keeping the pump pressure of the mortar pump at 0.5-0.7 MPa, closing a grout outlet valve when thick grout is discharged from the other end, increasing the pressure to 0.7 MPa, keeping the pressure for 2 minutes, and closing a grouting nozzle valve at the grouting end.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210723018.9A CN115262626B (en) | 2022-06-24 | 2022-06-24 | Construction method of underground space prestress steel reinforced concrete top cover under ultra-large span heavy load |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210723018.9A CN115262626B (en) | 2022-06-24 | 2022-06-24 | Construction method of underground space prestress steel reinforced concrete top cover under ultra-large span heavy load |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115262626A true CN115262626A (en) | 2022-11-01 |
| CN115262626B CN115262626B (en) | 2023-12-01 |
Family
ID=83760636
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210723018.9A Active CN115262626B (en) | 2022-06-24 | 2022-06-24 | Construction method of underground space prestress steel reinforced concrete top cover under ultra-large span heavy load |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115262626B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115853181A (en) * | 2022-12-23 | 2023-03-28 | 佛山市铁源建材科技有限公司 | Fabricated building floor and construction method thereof |
| CN116479997A (en) * | 2023-04-28 | 2023-07-25 | 中国人民解放军陆军工程大学 | High-resistance continuous rib method assembled bullet-proof layer and preparation method thereof |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101363250A (en) * | 2008-09-17 | 2009-02-11 | 新蒲建设集团有限公司 | Novel construction method of large area cast in site floor |
| CN102733603A (en) * | 2012-06-05 | 2012-10-17 | 中铁十八局集团有限公司 | Construction method for irregular floors with large span by utilizing high-strength steel strands |
| CN103132456A (en) * | 2013-03-19 | 2013-06-05 | 成军 | Construction method for large span girder with cementation pre-stress |
| CN103410329A (en) * | 2013-08-30 | 2013-11-27 | 南通八建集团有限公司 | Large-span basement concrete roof structure flat tube bonded prestressing force construction method |
| CN108951425A (en) * | 2018-07-12 | 2018-12-07 | 宁波市建设集团股份有限公司 | Cast-in-situ prestressed concrete continuous box girder primary concreting molding construction method |
| CN110159272A (en) * | 2019-05-22 | 2019-08-23 | 河南省交通规划设计研究院股份有限公司 | The construction method of large span city tunnel with box top board structure |
| CN114277672A (en) * | 2021-12-13 | 2022-04-05 | 中交三公局第三工程有限公司 | Large-span prestressed concrete bent cap structure and construction method thereof |
-
2022
- 2022-06-24 CN CN202210723018.9A patent/CN115262626B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101363250A (en) * | 2008-09-17 | 2009-02-11 | 新蒲建设集团有限公司 | Novel construction method of large area cast in site floor |
| CN102733603A (en) * | 2012-06-05 | 2012-10-17 | 中铁十八局集团有限公司 | Construction method for irregular floors with large span by utilizing high-strength steel strands |
| CN103132456A (en) * | 2013-03-19 | 2013-06-05 | 成军 | Construction method for large span girder with cementation pre-stress |
| CN103410329A (en) * | 2013-08-30 | 2013-11-27 | 南通八建集团有限公司 | Large-span basement concrete roof structure flat tube bonded prestressing force construction method |
| CN108951425A (en) * | 2018-07-12 | 2018-12-07 | 宁波市建设集团股份有限公司 | Cast-in-situ prestressed concrete continuous box girder primary concreting molding construction method |
| CN110159272A (en) * | 2019-05-22 | 2019-08-23 | 河南省交通规划设计研究院股份有限公司 | The construction method of large span city tunnel with box top board structure |
| CN114277672A (en) * | 2021-12-13 | 2022-04-05 | 中交三公局第三工程有限公司 | Large-span prestressed concrete bent cap structure and construction method thereof |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115853181A (en) * | 2022-12-23 | 2023-03-28 | 佛山市铁源建材科技有限公司 | Fabricated building floor and construction method thereof |
| CN116479997A (en) * | 2023-04-28 | 2023-07-25 | 中国人民解放军陆军工程大学 | High-resistance continuous rib method assembled bullet-proof layer and preparation method thereof |
| CN116479997B (en) * | 2023-04-28 | 2023-11-03 | 中国人民解放军陆军工程大学 | High-resistance continuous rib method assembled bullet-proof layer and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115262626B (en) | 2023-12-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN115262626B (en) | Construction method of underground space prestress steel reinforced concrete top cover under ultra-large span heavy load | |
| Raya | Standard specification for road works | |
| CN111455855A (en) | Construction process of main bridge of double-tower single-cable-plane short-tower cable-stayed bridge | |
| CN110607841B (en) | Wind tunnel prestress construction process | |
| CN110939051A (en) | Subway hidden cover beam construction method | |
| CN110184941B (en) | Bridge main tower construction method | |
| CN112982181A (en) | Construction method for steel-concrete combined section of through-type steel box continuous arch bridge | |
| CN113605771B (en) | Prestress assembly type frame structure system | |
| CN113738119A (en) | Large-span prestressed concrete beam roof tooth block tensioning construction method with bonding | |
| CN110468714B (en) | Longitudinal and transverse closure construction method of ultra-long-connection unequal-span asymmetric continuous bridge | |
| CN111997066A (en) | Manufacturing and construction method of assembled prestressed anchor cable frame beam for slope reinforcement | |
| CN113089491A (en) | Construction method of large cantilever prestressed concrete bent cap | |
| CN108755394B (en) | Method for reinforcing special-shaped pier column of bridge by using prestressed tendons | |
| CN107288024B (en) | Assembled beam body and construction method thereof | |
| CN113550335A (en) | Construction method for high slope concrete slope protection engineering | |
| CN112554560A (en) | Post-tensioning method prestress construction method for flat slab structure | |
| CN110747762A (en) | Cement member crossing highway and its installation method | |
| CN112726513B (en) | Prestressed hollow truss arch design and construction method | |
| CN112458915A (en) | Construction method of bent cap | |
| CN114059714A (en) | Construction process of bonded prestressed beam | |
| CN212404845U (en) | Temporary continuous beam pier beam consolidation system and continuous beam bridge | |
| CN114277672A (en) | Large-span prestressed concrete bent cap structure and construction method thereof | |
| CN211735010U (en) | Assembled earthing corrugated steel plate-prestressed concrete combination arched bridge | |
| CN210421155U (en) | Precast concrete base of corrugated steel plate comprehensive pipe gallery | |
| CN112695633A (en) | Prefabricated small box girder prestress engineering construction method for intelligent express way |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |