- Bridge formwork, brackets and arches
1. The knot is simple and stable, the pre-arching force of the load, the rod base is set with the symbol, and the rigidity is checked and the anti-tilt is calculated
(1) The formwork, bracket and arch should be simple in structure, easy to manufacture and assemble and disassemble, and should be designed according to various control conditions in the construction process, and should have sufficient bearing capacity, stiffness and stability.
(2) The design of the steel formwork and steel bracket shall comply with the provisions of the current national standards
(3) When designing the formwork, bracket and arch, the load combination should be carried out according to Table 1K412012.
(4) When checking the anti-overturning stability of templates, brackets and arches, the stability coefficient of each construction stage shall not be less than 1.3.
(5) Check the stiffness of the template, bracket and arch.
(6) The design of formwork, brackets and arches should be pre-cambered.
(7) When designing the prestressed concrete structure formwork, the elastic compression of the prestressed components, the displacement of the upper arch and the supporting bolts or embedded parts should be considered.
(8) The step distance of the vertical rod and horizontal rod of the bracket shall be determined according to the load beared, and its structural requirements and scissor brace settings shall meet the current specifications and standards.
(9) The foundation and foundation design of the bracket shall conform to the provisions of the current landmark where it is located, and the bearing capacity of the foundation shall be calculated.
2. Prepare materials in the knot across the load place
The design of formwork, brackets and arches should be carried out according to the conditions and relevant standards of the engineering structure form, design span, load, foundation category, construction method, construction equipment and material supply.
3. The general situation is based on the book materials, and the safety system is required to be dismantled
The construction design should include the following:
1) Project overview and engineering structure diagram.
2) The basis of structural design and design calculation.
3) General assembly drawings and detailed structure drawings.
4) The quality and accuracy requirements of production and installation.
5) Safety technical measures and precautions during installation and dismantling.
6) Material performance requirements and material quantity list.
7) Design instructions and instruction manuals.
4, 12 self-weight 5 side pressure, 3 walks, 4 vibrations, 6 tilting, wind and snow insulation 7 water, rigid and static strong static movement.
When designing the formwork, brackets and arches, the load combination should be carried out according to Table 1K412012.
| Table of load combinations for design formwork, brackets and arches Table 1K412012 | ||
| The name of the template component | 3 | |
| Calculate the intensity | It is used for stiffness checking | |
| Bottom mold and supporting plate, arch, bracket of beam, plate and arch | ①+②+③+④+⑦+⑧ | ①+②+⑦+⑧ |
| Side formwork for curbs, sidewalks, railings, columns, beams, slabs, arches, etc | ④+⑤ | ⑤ |
| Side formwork of thick structures such as foundations and piers | ⑤+⑥ | ⑤ |
Note: The meaning of the code in the table is as follows:
(1) The self-weight of the formwork, arch and bracket.
(2) The self-gravity of newly poured concrete, reinforced concrete or masonry and masonry.
(3) The load of walking, transportation or stacking of construction personnel and construction materials and equipment.
(4) The load when vibrating concrete.
(5) The pressure of the newly poured concrete on the side formwork.
(6) Horizontal impact load generated when pouring concrete.
(7) The current pressure, wave force, drift ice pressure, and impact force of ships and other floating objects borne by the scaffold located in the water.
(8) Other loads that may be generated, such as wind and snow loads, winter construction insulation facility loads, etc.
5, Lu Lu 4 hundred hidden 25, 500 hoops 1.5.
When checking the stiffness of templates, brackets and arches, their deformation values must not exceed the following provisions:
1) The deflection of the formwork exposed on the surface of the structure is 1/400 of the span of the formwork member.
2) The deflection of the formwork hidden on the surface of the structure is 1/250 of the span of the formwork member.
3) The elastic deflection of the members of the arch and the bracket after loading is 1/400 of the corresponding structural span.
4) The panel deformation value of the steel formwork is 1.5mm.
5) The deformation value of the steel flute and column hoop of the steel formwork is L/500 and B/500 (L calculation span, B - column width).
6. Pre-sinking of non-bullets
The following factors should be considered for the construction precamber of formwork, brackets and arches:
1) The precamber of the structure specified in the design documents.
2) The elastic deformation caused by the bracket and the arch bearing all the construction loads.
3) Inelastic deformation due to the compression of the extrusion and unloading equipment at the rod joint after loading.
4) Settlement of brackets and arch foundations after loading.
7. The pressure base is forbidden to bubble and freeze, the column is in the middle of the river, the support is not altogether, and the pressure frame is inspected in multiple layers.
(1) Before the bracket and arch are erected, the preloaded foundation should be qualified and recorded in accordance with the requirements of the "Technical Regulations for Preloading of Steel Pipe Full Hall Brackets" JGJ/T194-2009.
(2) The support column must fall on the foundation with sufficient bearing capacity, and the bottom end of the column must be placed with a backing plate or concrete cushion block. It is strictly forbidden for the bracket foundation to be soaked in water, and measures to prevent frost heave must be taken in winter construction.
(3) Piles, overhead limits and safety warning signs should be added on both sides of the bracket passage hole, and warning lights should be set up at night. The river support that is susceptible to the collision of drifting objects during construction should be provided with firm protective facilities.
(4) In the process of installing brackets and arches, temporary supports should be erected along with installation. When using multi-layer supports, the horizontal backing plate of the support should be horizontal, the columns should be straight, and the upper and lower columns should be on the same center line.
(5) The construction scaffolding and temporary bridge shall set up an independent support system, and shall not share the same support structure with the bracket or arch.
(6) After the erection of the steel pipe full house bracket is completed, the preload bracket shall be qualified and recorded in accordance with the requirements of the "Technical Regulations for the Preloading of Steel Pipe Full Hall Bracket" JGJ/T194-2009.
(7) After the installation of the bracket and arch is completed, the template can be installed only after passing the inspection.
8. Cooperate with the pier platform tilt and check the special argument
(7) the installation template should be carried out in cooperation with the reinforcement process, and the template that hinders the binding of the reinforcement should be installed after the reinforcement process is completed; when the pier platform template is installed, its bottom should be firmly connected with the foundation embedded parts, and the upper part should be fixed with the tie rod; in the installation process, the template must be provided with anti-overturning facilities.
(10) Before pouring concrete and masonry, the formwork, bracket and arch should be inspected and accepted, and the construction can only be carried out after passing the test.
(11) The formwork engineering and the construction of the support system belong to the sub-project with greater risk, and a special plan should be prepared before construction, and when it exceeds a certain scale (see Article 1K420053 of this book for details), the special construction plan should also be expertly demonstrated.
9. When checking leakage and stabilizing voltage
When the inflatable capsule is used as the core mold of the hollow component, its installation shall comply with the following requirements:
1) The capsule should be checked before use to confirm that there is no air leakage.
2) From pouring concrete to deflating the capsule, the air pressure should be kept stable.
3) When using the capsule inner mold, the positioning stirrups should be used to connect and fix the template to prevent floating and offset.
4) The deflation time of the capsule should be determined by the test, and the strength of the concrete should reach the degree that it can keep the component from deformation.
10、非不损，承加重，芯内不塌缝。
(1) The removal of formwork, brackets and arches shall comply with the following provisions;
1) The non-load-bearing side formwork should be dismantled only when the concrete strength can ensure that the edges and corners of the structure are not damaged, and the concrete strength should be 2.5MPa and above.
2) The core mold and the reserved channel inner mold should be allocated only when the compressive strength of the concrete can ensure that the surface of the structure does not collapse and crack.
3) The load-bearing formwork and support of the reinforced concrete structure should be dismantled only when the concrete strength can bear its self-weight load and other possible superimposed loads.
(4) The side formwork of the prestressed concrete structure should be dismantled before the prestressed tension, and the bottom mold should be dismantled after the structure is prestressed.
11. Masonry 80, small completion, solid abdomen arch protection, large empty abdomen arch horizontal
The unloading of the arch of the mortar masonry and concrete block arch shall comply with the following provisions:
1) mortar masonry, concrete block arch bridge should be unloaded after the mortar strength reaches the design requirements of the strength, when the design is not specified, the mortar strength should reach more than 80% of the design standard value.
2) The arch bridge with a span diameter of less than 10m should be unloaded after the arch structure is completed, the medium-span solid belly arch bridge should be unloaded after the arch protection is completed, and the large-span hollow arch bridge should be unloaded after the completion of the ventral arch transverse wall (unbuilt ventral arch circle).
3) When the arch is unloaded in the bare arch state, the strength and stability of the main arch should be checked and necessary stability measures should be taken.
12. Vertical and horizontal dismantling
The dismantling of formwork, brackets and arches should follow the principle of "first support and then dismantling, and then supporting and first dismantling". The bracket and arch should be discharged in several cycles, and the amount of unloading should be gradually increased from small to large. In each cycle, it should be discharged at the same time in the transverse direction and evenly disembarked in the longitudinal direction. The formwork of simply supported beam and continuous beam structure should be discharged in turn from the middle of the span to the direction of the support, and the formwork of cantilever beam structure should be discharged sequentially from the cantilever end.
Yesterday 速记口诀
1. Bridge composition
The lower branch is attached
2. Structures included in the substructure
Pier foundation
3. Bridge ancillary facilities
The face seam is sloped
4. The bridge deck system includes:
The water fence is clear
5. Common terms related to bridges
The arrow spans high, and the long line is hole
6. The classification of bridges
Force across the use of materials to obstruct the parking space
7. Bridges are divided according to the characteristics of stress
Beam arch rigid suspension group
8. Divided according to the span of the bridge
1138 or 15425
9. Bridges are divided according to their use
Highway and railway farmers transport water
10. Bridges are divided according to the materials used in the main load-bearing structures
Wood and steel mixing
11. Bridges are divided according to the nature of the obstacles they cross
Riverline viaduct
12. The bridge is divided according to the position of the carriageway of the superstructure
Upper, middle and lower bearing
Three days ago, shorthand mantra 4/5
1. Concrete mix ratio design
After a long time of strong labor and freezing, the water vapor is more than the mud doping
2. Cement concrete mixing equipment and the determination of the best mixing time
Intermittent calibration mixing, viscosity is strong and stable
3. Cement concrete mixing control and inspection items
than collapse vibration qi dampness secretion
4. Selection of cement concrete transport vehicles and transportation time limit
The feed distance is 2.5
5. Construction of concrete panel formwork
Support the prohibition of 185, check the high quartile, and inspect and seal the coating after installation.
6. Steel bar installation inspection
Germplasm retention
7. The operation mode, length of the operation unit and the configuration equipment of the three-roller screed
The front vibrates and then rolls quietly, and the interval is long and long
8. Track paver requirements
Spread wide, collapsed, loose and high, vibrate and level the table
9. Paving requirements for slipform pavers
Cabling Qingrunji high-frequency walking speed
10. Requirements for paving concrete with small machines
Loose paving brazing, before the initial setting, once poured vibrating.
11. The fixed installation method of the force transmission rod
The end of the wooden mold with the bracket
12. Regulations on cross-seam construction
Vertical width deep cut
13. Longitudinal joint construction requirements
Flat asphalt coated with tenons and grooves
14. Requirements for caulking after the expiration of the curing period of the concrete slab
Clean and clean sticky seams, low in winter, flat at room temperature
15. Cement concrete pavement maintenance
Wet cultivation should not be around low temperature maintenance
16. The cement concrete pavement is open to traffic
40 walkers complete and caulking
Seven days ago, shorthand mantra 4/1
1. The inorganic binder stabilizes the characteristics of the base layer
Water holes, technical scriptures
2. Characteristics of commonly used base materials
The plate is stable and frozen, shrinkage, subbase, early strong arch
3. Mix the base materials
The water transfer plant is strongly mixed, and the ash is mixed first with coarse screening
4. Mixture transportation
Lime cement is transported in time, anti-steaming and dust-proof.
5. Paving of base mixture
Wet and rainy seasons fall
6. Compaction and maintenance of lime stabilized soil and cement stabilized soil base layer
At the beginning of the day, it is condensed and pressed towards the seams
7. Lime fly ash stabilized gravel (gravel) base compaction and maintenance
The thickness of the layer is forbidden to be flattened, and the wet seven milk seals are raised
8. Compaction and maintenance of graded granular base layer
Sprinkle water for caulking, wheel track to open traffic
Two weeks agoShorthand mantra 3/25
1. Types of asphalt for asphalt pavement
A is preferred, B is not suitable for coal
2. The main technical properties of asphalt
Sticky temperature and long-lasting plastic
3. Adhesion of asphalt materials
Grain transfer strips
4. Temperature sensitivity of asphalt materials
The stickiness softens with temperature and the needle is high
5. Durability of asphalt materials
Bake hot water to resist aging
6. Types of cement for cement concrete pavement
Heavy fast master 425, silicon pu silicon and road
7. Requirements for coarse aggregate for asphalt mixture
Dense light is set up to crush and absorb soft particles
8. Requirements for coarse aggregate for cement concrete pavement
Gravel hard and clean (diameter)
9. Fine aggregate for asphalt mixture
Clean air mixed natural sand
10. Fine aggregate for cement concrete
The hard mold is coarse and sandy, and the mechanism is under the jurisdiction of the sea
11. Mineral powder for asphalt mixture
The water repellent is clean and clean, and the fast Lord should not be gray
12. Fiber stabilizer for asphalt mixture
Asbestos should not be wooden, stable two hundred and five
13. Admixtures for cement concrete
The air pump frost heave water is strong coagulation
14. Provisions for steel bars, force transmission rods (pull rods) and sliding sleeves for cement concrete
Product specification finished material factory
15. Expansion joint plate for cement concrete
Thick water and soft rot
16. Grout material for cement concrete
Old oak altered chlorine