Matters needing attention in the construction of river bank and Hechi

South Sewage Treatment Station 1000 cubic meter sewage cleaning pool is a supporting facility project in xx District of xxxxxxx Company, and we have contracted the civil engineering of the cleaning pool.

The sewage tank is 2 1.7m long and 4.3m wide, and the foundation is raft foundation. The relative elevation of 0.000 design of this project is taken as absolute elevation of 24.8m, and the relative elevation of foundation bottom elevation is-3.65m.. The seismic fortification intensity of this project is 6 degrees, the strength grade of foundation cushion concrete is C 10, the thickness is 100 mm, and the width of each side is 100. The concrete strength grade of the pool body is C25.S6.

Second, the steel engineering

1, construction deployment

1) construction sequence

Blanking according to the drawing-binding foundation and column reinforcement-binding wall reinforcement-binding roof reinforcement.

2) Labor arrangement

According to the characteristics of this project, the reinforcement processing arrangement is 10, the reinforcement transportation arrangement is 4, and the reinforcement installation arrangement is 15.

2, construction preparation

1) technical preparation

1. 1 The technical and construction personnel related to this project are fully equipped.

1.2 be familiar with the drawings, and check whether the drawings are consistent with the description, whether there are contradictions and errors in each component, and whether the dimensions and elevations on the architectural drawings and structural drawings are consistent.

1.3 master the construction methods and technical requirements of this project.

Site preparation

2. 1 elevation point shall be measured according to 0.000 of field putright.

2.2 Some steel processing machinery and equipment shall enter the site in advance according to the construction plan and relevant regulations.

2.3 According to the requirements of the drawings, various types of steel bars shall enter the site in advance, and sampling inspection shall be conducted as required.

2.4 Various measures for rainy season construction.

3, the construction method

1, steel processing

1. 1, the shape and size of steel bar processing must meet the design and specification requirements, and the surface of steel bar should be clean without damage, oil stain, paint spot and corrosion. If yes, it must be removed before use, and steel bars with granular old rust shall not be used.

1.2, steel bar derusting adopts steel bar straightening machine for derusting in the process of steel bar straightening.

1.3, the steel bar must be straight without local twists and turns, and it can only be used and processed after straightening.

1.4, steel hook or bending shall meet the following requirements:

1) The end of Grade I steel bar shall be bent into a hook of 180 degrees, with the bending radius not less than 2.5 times the diameter of steel bar and the length of straight part not less than 3 times the diameter of steel bar.

2) When the ends of secondary reinforcement are hooked at 90 degrees or 135 degrees, the bending radius d of secondary reinforcement should not be less than 4 times the diameter of reinforcement, and the length of straight part should be determined according to the design (03-10/atlas).

3) The bending radius d at the bend in the middle of the bending steel bar should not be less than 5 times the diameter of the steel bar.

4) The end of the stirrup should be bent into a hook of 135 degrees, the bending diameter of the hook should be greater than the diameter of the stressed steel bar and not less than 2.5 times of the stirrup diameter, and the straight length of the hook should not be less than 10d of the stirrup diameter.

5) When cutting materials mechanically, the materials shall be cut in strict accordance with the length of the ingredient list, so as to ensure that the materials are cut correctly, the cutting edges of the steel bars and the cutting machine shall be vertical, and the operation procedures shall be strictly implemented to ensure safety. In the process of cutting and cutting, if the steel bar is found to have splitting, shrinkage or serious elbow, it must be removed.

6) In order to ensure the processing quality of steel bar bending in this project, when it is processed below φ 10, it is required to nail nails on the workbench according to the size of the ingredient list as a sign of the size (bending point).

7) When bending thick steel bars and steel bars with complex shapes, the bending point position must be drawn with chalk according to the size indicated on the ingredient list before bending steel bars, and samples should be drawn on the workbench when necessary, and the bending point of steel bars should be controlled with nails on the workbench. When marking the nail point, the bending adjustment value should be deducted according to different bending angles (see table 1).

Rebar Bending Adjustment Value List

Bending of steel bar

Angle 30 45 60 90 135

Bending of steel bar

Adjustment value 0.35d0.5d0.85d2.0d2.5d

8) After the first steel bar is bent and formed, it should be rechecked according to the shape and size indicated on the ingredient list, and then processed in batches after it meets the requirements. Molded steel bars shall have the correct shape, with no concave bending on the plane and no cracks at the bending points.

9) After the round steel is straightened by the straightening machine, the locally bent steel bar can be straightened with a wrench.

10) allowable deviation of reinforcement processing:

List of allowable deviation values for steel bar processing

Allowable deviation of the project

The net size of the total length of reinforcement along the length direction is 10.

The bending position of the bending steel bar is 20.

The internal net size of stirrups is 5.

2, the installation of reinforcement

1, column reinforcement installation

1. 1 Tie the column steel dowel according to the given column position line (scaffolding should be erected before entering the high level) and control its spacing.

1.2 Set column stirrups, and calculate the required number of stirrups according to the spacing given on the drawing. The joints of stirrups should be staggered on the longitudinal steel bars at the four corners, and the steel bars at the column corners and stirrups should be staggered and bound with double buckles, and the binding buckles are splayed with each other, and the stirrups should be perpendicular to the main reinforcement.

1.3 The protective layer thickness of column rebar shall meet the design and specification requirements.

2, plate reinforcement installation

1) process flow: clean the formwork → draw lines on the formwork → bind the plate bearing steel bar → bind the negative moment steel bar and angle steel bar.

2) Clean up the sundries on the template, draw the spacing of the main reinforcement distribution bars on the template with chalk, and put the stressed steel bars first and then the distribution bars according to the drawn spacing.

3) Tie the buckle into a figure of eight. When binding, the first steel bar is 50 mm away from the beam edge, and when the last steel bar is more than 50 mm away from the beam edge, one more steel bar can be bound;

4) Tie double-layer steel mesh with negative reinforcement, and add Ф 8 spacing 1 piece/㎡ to ensure the position of upper reinforcement.

5) When pouring, the short-span main reinforcement should be placed under the long-span main reinforcement, and the anchorage length of the reinforcement in the beam should not be less than10d; ;

4, quality standards

1, master project

When installing 1. 1 rebar, the variety, grade, quantity and specifications of rebar must meet the design requirements and the current national building material standards;

1.2 The type and quality of welded joints of steel bars meet the requirements of the current Code for Welding and Acceptance of Steel Bars (JJ18-96);

1.3 The connection mode of longitudinal reinforcement meets the design requirements;

1.4 When the steel bars are found to be brittle, poorly welded or obviously abnormal in mechanical properties, the chemical composition inspection or other special inspection shall be conducted for this batch of steel bars.

2. General items

2. 1 The steel bar shall be straight and undamaged, with no cracks, oil stains, granular or flaky old rust on the surface.

2.2 Steel bar joints should be set in places with less stress. It is not advisable to set two or more joints for the same longitudinal reinforcement. The distance from the end of the joint to the bending starting point of the steel bar should not be less than 10 times the diameter of the steel bar.

2.3 The number of missing or loose buttons shall not exceed 10% of the number of buttons, and shall not be centralized;

2.4 steel binding in place accurately, binding joint should comply with the current specification requirements.

The allowable deviation of steel bar installation is shown in the following table:

Test method of allowable deviation of project

The length and width of the binding steel mesh are 10 foot.

Mesh size +/-20 feet. Check the third gear and get the maximum value.

Binding steel skeleton length 10 foot quantity inspection.

Check the width and height of 5 feet.

Check the rebar spacing 10 foot.

Check the 5-foot spacing.

The thickness of the protective layer is based on 10 foot.

Check the columns and beams at 5 feet.

Check boards and walls within 3 feet.

When binding stirrups, the spacing between transverse reinforcement shall be 20 feet. Check the third gear and get the maximum value.

20-foot quantity inspection of starting point position of steel bar bending.

Check the center line position of embedded parts with 5 feet.

Level difference +3, 0 foot quantity inspection

5, civilized construction and environmental protection measures

1, quality assurance measures

1. 1 shall be constructed in strict accordance with relevant national codes, regulations and design requirements. Implement total quality management, who is responsible for the construction, strictly control the construction process, and clarify the division of responsibilities.

1.2 implement a three-level quality management system to ensure that the construction time is controlled.

1.3 Make original records of various constructions in time, accurately and in detail, so as to find problems in time and adjust the construction scheme at any time.

1.4 The construction personnel shall control the whole construction process in strict accordance with the ISO-9002 standard and the standards specified in the company's quality control procedure documents, and the construction personnel shall operate in strict accordance with the requirements of the construction plan and work instructions.

2, safety construction technical measures

2. 1 The project manager of this project takes overall leadership responsibility for the safety of the whole project, and technicians, functional departments and production workers at all levels take corresponding responsibilities for the safety work within their respective responsibilities.

2.2 Strengthen the safety construction education for construction personnel and conduct regular safety inspections.

2.3 When entering the construction site, you must wear a safety helmet and receive admission education.

2.4 During construction, each professional type of work must hold relevant certificates and strictly implement safety operation procedures.

2.5 The project management personnel shall conduct legal education for all the construction personnel to observe the rules and discipline, and do a good job of safety disclosure before construction. No one is allowed to command and operate in violation of regulations, and obey the management of security personnel.

2.6 During the construction period, the safety officer will be fully responsible for safety supervision. Once unsafe factors are found, they will be eliminated at any time and effective preventive measures will be taken.

2.7 Matters not covered shall be implemented in accordance with relevant operation procedures.

3, civilization and finished product protection measures

3. 1 Workers' workplaces and surrounding environment must be clean and tidy, and their feet should be clean after work and after work.

3.2 Strengthen the maintenance and repair of machinery and equipment, abide by the safety operation rules of machinery and take safety protection measures to ensure the normal operation of machinery; Always keep the fuselage and surrounding environment clean.

3.3 Various materials and tools used in the construction shall be arranged in a planned way according to the construction progress and site conditions.

3.4 after the completion of steel binding, no one is allowed to walk around on the floor;

3.5 The processed molding steel bars shall be neatly stacked according to the model and specification at the site to prevent bending deformation; Drainage ditches shall be set around to prevent steel bars from falling into the soil; After the bottom plate reinforcement is bound, the support and horse stool should be firmly bound to avoid trampling deformation during other types of work;

3.6 temporary scaffolding shall be erected when binding the wall reinforcement, and the reinforcement shall not be trampled;

3.7 When transporting and installing steel bars, they should be unloaded lightly, and throwing and collision are not allowed at will.

3.8 After the steel bar binding is completed, set the overhead board as a temporary passage on the board to avoid people trampling on the steel bar up and down;

3.9 When pouring concrete, pedestrians and operation passages shall be erected, and concrete construction shall not be carried out on steel bars.

3. 10 After the steel bar binding is completed, the site should be cleaned after the work, and the remaining iron wires and steel bars should be piled up in time.

Second, the template project

1. Compilation basis

1, construction drawing of clean water tank

2. Code for Quality Acceptance of Concrete Structures (GB50204-2002)

3. Technical Code for Safety of Fastening Steel Pipe Scaffolding in Building Construction (JJ130-2001).

2. Deployment of labor force

Template installation needs to invest 20 people every day.

3, template production:

According to the drawings, process or make models at the processing site, and mark the template position, model size and quantity after making.

1. Template installation

Construction sequence:

Pay-off → raft foundation and independent column foundation formwork and wall-hanging formwork → column formwork installation → formwork-free wall formwork installation → plate bottom formwork installation.

(1) Pay-off:

Before formwork installation, control the inner edge line according to the elevation, center line and formwork installation popped up on the cushion layer, foundation and board surface, and determine the position line of formwork column according to the design requirements of full frame.

(2) The erection of formwork support:

The erection spacing of full-house scaffolding is @800×800, and cannot be greater than1000 mm.. The first horizontal bar is set at a height of 300㎜ from the ground, and the spacing between the second and third horizontal bars is set at 1500mm. Vertical and horizontal rods and supports must be tightened with fasteners.

(3) Installation of wall formwork

The main formwork is made of wood formwork, reinforced with 50× 100 wood square, steel pipe and 10㎜ diameter bolts. (back to the surface of the template, spacing is 200㎜, the horizontal and vertical spacing of the bolt is 500㎜. Sealing ring and steel jacking are welded in the middle of the bolt to prevent water leakage, and the cross section becomes smaller when pouring concrete. The steel pipes are horizontally backed on the wood square with the same spacing as the bolts. Then use steel pipes to support on the earth wall, with the spacing of 1500㎜.

(3) Install the bottom die of the plate:

The support must be stable and will not sink. According to the design requirements, set full scaffolding poles at intervals. For the template, should stay to control the height and verticality, and check the leveling.

The formwork shall be laid from all sides to the middle, connected with the supporting steel pipe keel and the wall internal model, and firmly connected with nails. The formwork covers the internal model of the wall, and adhesive tape is attached to the joints of the formwork. After inspection, the release agent is applied.

After the position line pops up on the template, the embedded parts and reserved holes on the template should be embedded to ensure the accurate position and fixed with steel pipes or other methods.

After the bottom die is installed, the accuracy of the template surface elevation, surface flatness, flat-fell seam, embedded parts and reserved holes should be checked, and the position of the nuclear column should be further determined.

(4) column seam template installation:

The gaps at the joints between the plate template and the column template and the plate template are closely stitched with wood veneer and adhesive tape to prevent slurry leakage and reinforce them firmly; Check whether the flatness is the same as and perpendicular to the bedding face.

4. Mold installation

(1). Assemble the mold strictly according to the mold drawing.

(2). Release the column sideline and 500 subsidiary lines, correct and bind the column rebar and install the cushion block, and use high-grade mortar to make edge lines along the column periphery to ensure that the formwork is square.

(3) Template installation, correction and reinforcement. When installing the mold, the model should be installed in place at one time.

(4) The formwork reinforcement system adopts steel pipes with a horizontal spacing of 500. All sides are reinforced with steel pipes, and the roots are properly encrypted to prevent the formwork from expanding.

(5) The mould must be cleaned before dust removal.

5. Template installation self-inspection

After the formwork is supported, self-inspection shall be carried out first, and the self-inspection and self-evaluation form shall be filled in, and then submitted to the project department and Party A's company for acceptance. After the acceptance, the handover procedures shall be completed, and then the next working procedure shall be constructed. Almost! Thank you, please give points!