catalogue

I. Compilation Basis 1

Two. Project overview: 1

Three. Construction scheme 2

1, construction preparation 2

2, construction lofting 2

3, binding reinforcement 2

4, template installation 4

5, concrete pouring 5

6, demolition, health 7

Four, tie beam construction quality requirements standard 7

Five, mechanical equipment and staffing 8

Measures to ensure quality, safety, environmental protection and occupational health by intransitive verbs

Seven. Construction Layout 10

Attached drawings 1: Block diagram of tie beam construction technology 1 1

I. Basis for compilation

1, bidding documents for Shifeng highway engineering construction;

2. Construction drawing design documents of Shifeng Highway Project;

3. Relevant technical standards and specifications;

4. Existing relevant laws and regulations;

5. Construction experience of similar projects in our unit and relevant information obtained after entering the site;

Second, the project overview:

1, engineering situation

In the bridge engineering of this project, the upper part of the middle bridge in Wenjiaogou is prefabricated with 3-20m prestressed reinforced concrete simply supported hollow slab. The lower part adopts reinforced concrete pier, pile foundation and gravity U-shaped abutment. The central pile number of the bridge is K52+ 18 1, and the whole bridge runs through.

There are 2 root beams and 2 abutment bodies in the middle bridge in Wenjiaogou of this project. The design strength of tie beam concrete is C30.

2. Geological and hydrological conditions

Wenjiaogou Middle Bridge is located in Luowang Township, yiliang county, Zhaotong City, Yunnan Province, adjacent to Baishui River, and the highway from niujie to Wang Luo passes in the northeast. Within the bridge site, it belongs to low hillside landform, with structural erosion and deep cutting depth. The ground elevation is 596.0 ~ 644.0 m, and the height difference is 48 m. The bridge site area passes through the cultural and educational ditch in a U-shape and extends from north to south to Baishui River. The bank of Shiziba dam is covered with residual loam, with a slope direction of 100 and a slope angle of 25 ~ 50. The bedrock of Feng Yong 'an abutment is exposed, and the slope is covered with alluvial sandy pebble soil, with a slope direction of 275 and a slope angle of 40 ~ 65.

Third, the construction scheme

According to the actual construction situation, design documents and our company's previous construction experience, the tie beam adopts the finalized composite steel formwork.

1, construction preparation

1. 1, measure the setting-out with total station according to the design drawings;

1.2, the concrete mixture ratio has been completed and approved by the supervision engineer;

1.3, raw materials such as sand, stone, cement and steel bars have passed the laboratory inspection;

1.4, technical disclosure to the construction team;

1.5. All the mechanical equipment and testing instruments configured in the project construction have come into play and are running well.

2, construction lofting

According to the design drawings, re-measure the setting-out with total station, set out the center position of tie beam, and check it with the actual tie beam center.

3, binding steel bar

All steel bars used for construction are concentrated in the processing plant and then transported to the site for binding and installation. The construction requirements for steel bar production are as follows:

The surface of steel bar should be clean, and the surface oil stain, paint skin and rust scale should be removed before use;

Steel bars should be straight without local bending, and circular steel bars and bent steel bars should be straightened;

The steel bar is straightened by cold drawing method, and the cold drawing rate of R235 brand steel bar should not be greater than 2%; The cold drawing rate of HRB335 brand steel bar should not be greater than 65438 0%;

When processing ingredients for steel bars, accurately calculate the length of steel bars, increase the length of steel bars with hooks or bends, and deduct the protruding length of steel bars formed by bends to match the actual length of steel bars. For all kinds of reinforcement numbers (design numbers) with different lengths of the same kind of reinforcement, fill in the ingredient list in sequence first, and then uniformly mix the ingredients according to the straightened reinforcement length to reduce the breakage and welding amount of reinforcement;

After the steel bar is processed and formed, the size and shape should be checked in detail, and attention should be paid to whether there are cracks; Steel bars of the same type shall be stored together, and after the first type is bent, they shall be bundled and numbered with labels, indicating the specifications and dimensions of steel bars, and indicating the name of the project used if necessary;

Reinforcement installation and construction requirements:

1) formed steel bar, if two steel bars need to be bound or tied together by a welder;

2) Bending steel bars should be carefully handled during transportation to avoid deformation, and corrosion caused by rain, humidity and other harmful gases should be avoided during storage;

3) Lap arc welding and double-sided welding are adopted for the rebar joint. When double-sided welding is difficult, single-sided welding can be used, and arc welding can be used for steel joints. The overlapping ends of two steel bars should be folded to one side in advance, so that the axes of the two connected steel bars are consistent. The length of double-sided weld of the joint shall not be less than 5d, and the length of single-sided weld shall not be less than 10d(d is the diameter of reinforcement);

4) All welded steel bars and plates shall have material certificates or test reports. Covered electrode, flux should have a certificate of approval, covered electrode model adopts 502 or 506, and the performance of various welding materials should comply with the current Code for Welding and Acceptance of Reinforcement (JJ18). All kinds of welding materials should be classified and properly managed, and measures should be taken to prevent corrosion and moisture deterioration;

5) Welded or bound joints of stressed steel bars shall be arranged in places with small internal forces and staggered. For binding joints, the distance between two joints shall not be less than 1.3 times the overlapping length;

6) The intersection of each steel bar shall be firmly bound with iron wire and welded by spot welding when necessary;

7) Inspection before pouring: A cushion block is set between the steel bar and the formwork, and the cushion block and the steel bar are tightly bound and staggered. Support multi-layer non-welded steel bars with short steel bars to ensure accurate position.

8) All rebar processing and installation must be qualified by self-inspection and approved by the supervision engineer before entering the next working procedure;

9) The number of galvanized iron wire shall be bound with 16.

4, template installation

In order to ensure the quality, appearance, size and smoothness of concrete, except for the bottom formwork of ground pier bottom tie beam, abutment cap or middle bottom tie beam, C 10cm thick concrete is poured on the original basis, and the rest formwork is steel formwork. Template surface should be smooth, flat, straight, fixed with bolts when installation, joint sealing, no leakage, alignment; Take reinforcement measures, and reinforce the side formwork of pier beam according to the horizontal thrust of 18.5KN/M2; The bottom formwork of the beam in the pier is reinforced according to the vertical force of "250KN+ self-weight of formwork+weight of construction personnel and machinery"; The lateral formwork of abutment cap is reinforced according to the horizontal thrust of 23KN/M2; Surrounded by three steel hoops, the middle is reinforced with opposite bolts to prevent the template from deformation and displacement. Zhongliang 14 I-beam is bolted to the reserved hole of the cast pier, and then channel steel is laid on the I-beam, and sleepers are laid on the channel steel. Finally, install the bottom die and the side die.

Template installation adopts truck crane, manual operation. After the installation is completed, the project department shall conduct self-inspection on the template, and the next working procedure can only be carried out after the quality inspection is qualified and approved by the supervision engineer.

Before the formwork is installed, the interior of the formwork shall be cleaned and coated with release agent or fresh engine oil, and waste engine oil shall not be used.

Attached with scaffold structure diagram:

5, concrete pouring

Concrete is mixed in the mixing station and transported to the construction site by concrete tanker. When pouring concrete, lift the ash hopper with a crane to send the concrete into the mold, and install a series of cylinders in the mold to prevent the concrete from segregation. The thickness of concrete pouring layer shall not exceed 30cm according to the specification requirements, and it shall be vibrated with an internal vibrator. The vibrator can only be inserted into the concrete after it is started. After the vibration is over, it should be raised slowly, and the nose should not be pushed aside too fast or stopped to avoid leaving holes. The vibrating rod keeps a certain distance from the template, generally 10cm. After pouring the bottom concrete, when pouring the upper concrete, insert the vibrator slightly into the lower layer (not less than 5cm) to combine the two layers. In order to prevent excessive vibration or vibration leakage, it is advisable to stop the sinking of concrete, with a smooth surface and full of cement slurry.

Concrete shall be mixed in the mixing station, and the shortest mixing time shall be1.5min. When mixing, the water cement ratio shall be strictly controlled, and water shall not be added at will.

Concrete is transported by concrete tank car, and there is no segregation, slurry leakage, serious bleeding and excessive slump loss during transportation. If segregation occurs during transportation, secondary stirring shall be carried out, and water shall not be added at will during secondary stirring. When necessary, water and cement can be added at the same time to keep the original water-cement ratio unchanged. If it still does not meet the requirements after the second stirring, it shall not be used.

After the concrete is transported to the construction site, its slump should be checked, and at least three groups of concrete specimens should be made for each pier beam and each abutment cap.

Concrete should be poured horizontally and in layers from bottom to top. When vibrating, the moving distance of the internal vibrator shall not exceed 1.5 times of the action radius of the vibrator, and keep a distance of 50- 100mm from the side formwork. Insert the lower concrete 50- 100mm, after each vibrating, slowly raise the vibrator to avoid the vibrator colliding with the steel bar and the formwork, and prevent the deformation and displacement of the steel bar and the formwork. For each vibrating part, it must be vibrated until the concrete in that part is dense. The sign of compactness is that the concrete stops sinking, no more bubbles appear, the surface is flat and full of slurry.

When concrete is directly dumped from a height, its free dumping height should not exceed 2m; When the dumping height is more than 2m, it should pass through the facilities such as string tube or chute, and the concrete accumulation height below the string tube outlet should not exceed1m..

Concrete pouring shall be carried out continuously. If it must be interrupted for some reason, the interruption time should be less than the initial setting time of the previous layer of concrete. If the time specified in the specification is exceeded, construction joints shall be reserved.

All allowable time for concrete transportation, pouring and intermission (minutes)

The temperature of concrete strength grade is not higher than 25℃, and the temperature is higher than 25℃

≤C30 2 10 180

> C30 180 150

Pay attention to the embedded pier reinforcement, and require the embedded position to be accurate. In the process of concrete pouring, there should be special personnel to check the stability of supports, templates, steel bars and embedded parts. If looseness, deformation and displacement are found, they should be handled in time.

When the temperature is lower than 5℃, concrete shall not be poured.

6, demolition, health

Immediately after concrete pouring, cover with water for curing. When the concrete strength reaches 2.5Mpa, the side formwork can be removed. When the concrete strength reaches 75% of the design strength, the bottom formwork (intermediate tie beam) can be removed. After the side formwork is removed, the straw mat is wrapped or covered and watered for 7 days. The frequency of watering every day is to keep the concrete surface in a wet state.

Appearance inspection of concrete after formwork removal: the appearance quality inspection shall be carried out after formwork removal, and the appearance quality standard is: 1) The concrete surface is smooth, with straight edges and corners and no obvious construction joints; 2) The area of honeycomb and pits shall not exceed 0.5% of the total area; 3) Non-stressed cracks do not appear on the concrete surface.

During the curing period, when the temperature is lower than 5℃, thermal insulation materials should be covered immediately, and thermal insulation measures should be taken to prevent concrete from freezing injury.

Four, tie beam construction quality requirements standard

4. 1, the concrete surface is smooth, the construction joints are smooth, the edges and corners are straight, and the color of the exposed surface is consistent.

4.2, concrete surface can not have holes and exposure phenomenon, honeycomb pits area shall not exceed 0.5% of the surface area.

4.3, the measured project

Tie beam measured project

The frequency and method of checking the specified value or allowable value of each item.

1 The concrete strength is within the acceptable standard.

2 section size plus or minus ±20mm check 3 sections.

3 axis deviation 65438±00mm with total station check.

4 Top surface elevation 10 mm elevation: check 3-5 points.

Five, mechanical equipment and staffing

See the following table for mechanical equipment and staffing:

Number of personnel and labor force on mechanical platform (vehicle)

/kloc-6 0/2m3 tank cars

Reinforcement worker 10

25T truck crane 1 template 10

16T truck crane 2 concrete workers 10

6m3 tank car 2 assemblers 6.

ZL-50 loader, 2 electricians and 4 electricians.

Welding machine 6 technician 6

Cutting machine 1

Plug-in vibrator 2

Air compressor 2.5m3 (units)

2.5m3 (Taiwan Province) 3

YT-23 Rock Drill (Table)

2

Excavator PC200 (Taiwan Province)

2

Silk threading machine 1

Reinforcing bar forming machine 2

Measures to ensure the quality, safety, environmental protection and occupational health of intransitive verbs

1, quality assurance measures

1. 1. Quality objective: first pass rate 100%.

1.2, before construction, the construction technical director should organize technicians and construction management personnel to read the design documents carefully, understand the design intent, clarify the key points and difficulties of construction technology, and make technical disclosure.

1.3, implement the construction quality responsibility list system, indicate the managers and operators, and whoever is responsible for the construction.

1.4, strict material procurement and inspection system, and untested materials are strictly prohibited from entering the whole project.

1.5. Adhere to the "three inspections" system in the construction process, so as to achieve "the last procedure is inspected, the next procedure is well done, and the next procedure is served".

1.6, the quality rejection system shall be implemented between processes to ensure that each process 100% is qualified.

1.7, strictly measure and set out, with accurate measurement requirements, timely setting out, and correctly guide the construction.

1.8, mix proportion test shall be conducted before concrete mixing. After the strength meets the requirements, it can be used for construction. Strict measurement should be carried out during construction, and regular and fixed-point sampling inspection should be carried out according to the specifications.

1.9, after the completion of concrete construction, earnestly do a good job of maintenance.

2. Safety assurance measures

2. 1, establish a safety guarantee system.

Project set up safety management organization, set up on-site safety supervision and inspection team, carry out safety disclosure according to process characteristics, strictly implement the relevant provisions of the safety assurance system of the project management department, and the management department signs a safety production responsibility letter with each operator.

2.2, safety education and training

2.2. 1. Conduct safety education and training for new workers. Only after passing the examination can you enter the operating post.

2.2.2, for lifting, welding special types of workers, special safety operation training. Use the certificate.

2.2.3 When adopting new technologies, new methods, new equipment or changing jobs, workers should be given safety education on new operation methods and new jobs.

2.2.4, set up a weekly safety activity day, check the safety production activities at the meeting before and after work, and conduct regular safety education and safety publicity activities for employees.

2.3, the implementation of the safety responsibility system, formulate various rules and regulations of safety management.

Establish and improve various rules and regulations and management systems for safety production, embody the basic idea of "all staff management and safety first", clarify the responsibility for safety production, and make the responsibility clear and personal. In the process of construction, in addition to the operators themselves to strengthen various safety measures, the management department will also intensify inspection, do a good job of coordination in all aspects, and resolutely put an end to all kinds of accidents. Strictly implement the construction safety operation procedures.

2.4, all kinds of safety technical measures

2.4. 1. Construction operators must wear safety helmets when entering the site, and electricians and welders must wear insulating shoes. Power supply wiring must be standardized.

2.4.2. Full-time security officer shall be appointed for site construction, responsible for site safety management and establishing safety guarantee system.

2.4.3. All kinds of construction machines and tools should be inspected and maintained regularly to ensure safe use. All construction machinery shall be operated by special personnel, and others shall not operate it without authorization.

2.4.4. Hang the operation instruction card in a prominent position of the equipment, and the instruction card shall indicate the machine name, model type, operation method, maintenance requirements, safety precautions and special requirements.

3, environmental protection and occupational health assurance measures

3. 1, establish and improve the management organization. A civilized construction and environmental protection management organization with the project manager as the team leader and various business departments and production teams as members was established on site.

3.2, strengthen education and publicity work, improve the civilized construction and environmental awareness of all employees.

3.3, formulate rules and regulations, strengthen inspection and supervision.

3.4, strengthen the management of civilized construction, reasonable layout of the construction site, reasonable placement of various construction facilities.

Seven, the construction layout

See attached drawings.

Attached drawing 1: Block diagram of tie beam construction technology