Safe construction plan for bridge construction full-tank supports

Mantang Support Safety Special Construction Plan

1. Basis for preparation

1. Construction drawing design documents of the XTK-6 contract section of the West Copper Expressway reconstruction and expansion project ;

2. On-site geological and hydrological survey data;

3. "Technical Specifications for Construction of Highway Bridges and Culverts" (JTJ 041-2000);

4. Highway Engineering Construction Safety Technical Regulations" (JTJ076-95).

5. "Design Code for Steel Structure and Timber Structure of Highway Bridges and Culverts" (JTJ025-86).

6. "Steel Structure Design Code" (GBJ17-88)

7. "Highway Bridge and Culvert Construction Manual" and other relevant current national and local mandatory codes and standards

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8. "Safety Technical Regulations for Fastener Steel Pipe Supports in Construction" (JGJ130-2001)

II. Preparation Scope

XTK- 6. Viaducts, overpasses and arch culverts in the contract bid section.

3. Preparation Principles

1. The principle of safety first

In the preparation of safety plans, always follow the principles of reliable technology, effective measures, reasonable construction sequence, and Determine the construction plan based on the principle of ensuring safety.

2. Adhere to the principles of norms and procedures

Implement the technical specifications for highway subgrade construction and the technical regulations for safe construction of highway projects. Implement the owner's requirements for various safety management measures, rules and procedures for the construction of this project.

IV. Main construction technical solutions

The cast-in-place construction adopts the cast-in-place method of the full hall bracket. The construction process is: foundation reinforcement → measurement and setting-out positioning → erection of brackets → erecting base formwork → Preloading → Adjustment of bottom form → External formwork → Binding of bottom plate and web steel bars → Installation of inner form → Binding of top plate steel bars → Pouring of concrete → Maintenance → Dropping and removal of formwork.

1. Foundation reinforcement

Clear the surface layer, level it, replace it with 8% lime soil, compact it with a road roller, and use a small tamping machine to densify the surroundings of the foundation pit. pressure. The cross-bridge span direction is laid with sleepers under the portal steel bracket base.

2. Bracket erection

The bracket steel pipes are arranged at a vertical and horizontal spacing of 0.9m, and a 0.6×0.6m layout is adopted at the beams and webs. An adjusting screw is installed under the steel pipe. In order to ensure the stiffness of the bracket, vertical and horizontal reinforcing tie rods are set up, one every 1.2m along the height direction, and adjusted to 0.6m at the bottom of the beam to ensure the overall stability of the bracket. The vertical and horizontal frames at the bottom of the formwork are made of square timbers with cross-sections of 0.15×0.15m and 0.1×0.1m respectively. The spacing between longitudinal beams and transverse timbers is 0.9m and the spacing between horizontal timbers is 0.3m. The additional width of the bracket is 1m wider on each side than the width of the box beam, which is used as a formwork to stack the inner formwork and walking space.

3. Preloading

After the brackets and vertical and horizontal beams are erected, the bottom formwork should be laid in advance and temporarily fixed. Sand in cement bags should be used as the ballast, and the ballast weight should be the weight of the beam. 1.05 times of the load. Observation points are set up on the beam before preloading. An observation point is set up every two meters under the formwork along the horizontal and vertical bridge directions. ***Observation before loading, half loading, loading completion, 24h loading, and 48h loading , wait 6 times until the uninstallation is completed. Based on the analysis of observation records, the deformation of the foundation and brackets can be determined to provide reference values ??for future cast-in-place brackets. During the preloading process, the bracket and the bottom mold are continuously observed to detect the stability of the bracket and whether the deformation of the mold bottom exceeds the limit.

4. Formwork production and installation

The bottom plate is made of 20mm bamboo glue panel, covered with floor leather. After the bottom formwork is laid, the laying out positioning is carried out to determine the webs and beams. Location. The formwork is installed in three steps: the first time is to erect the bottom formwork, the web outer formwork, the wing bottom formwork, the second time is to erect the web inner formwork, and the third time is to erect the roof bottom formwork. There are two Φ16 tension rods on the inner side of the box girder. The fixed tension rods are embedded in the concrete through PVC pipes. In order to prevent the bottom mold from floating during the concrete pouring process, Φ12 compression steel bars are set up and welded to the bottom plate steel bars.

5. Falling frame and formwork disassembly

In order to check the strength of the box beam when the formwork is dismantled, 3 to 4 more sets of test blocks should be maintained under the same conditions as the beam body. The strength of the comparison test blocks reaches The box beams must be designed to be strong enough to be placed on the frame and removed from the formwork.

Rotate the adjusting screw under the vertical pole, and remove the wooden wedges between the vertical and horizontal square timbers. The frame is placed symmetrically from both sides with the pier as the center to prevent damage to the concrete. After removing the formwork and placing the frame, promptly remove the mortar dirt on the beam body to confirm that the box beam is beautiful inside and out.

V. Construction technology assurance measures

1. Design disclosure

The engineering department and team technical office will go to the construction site to conduct technical disclosure, and carefully organize relevant personnel to conduct Research and field verification work. All construction technicians are required to fully understand the design intentions and be aware of them.

2. Measurement review

Carry out measurements according to construction requirements, review and retest step by step, and report to the supervision engineer for retest.

3. Strictly implement the technical management system

Develop detailed construction techniques for the bracket construction process to ensure construction quality.

4. Engineering test

Carry out on-site test work carefully, provide various technical parameters for on-site construction in a timely manner, correct problems in a timely manner and take remedial measures if problems are discovered.

5. Rain and winter construction

Take some necessary rainproof measures during construction in the rainy season, such as covering and setting up rainproof sheds. Set up rainproof sheds on prefabricated box beams and other places, which can be used as insulation sheds during winter construction, and antifreeze work must be done.

6. Quality Assurance Measures

1. Quality Assurance System

(1) The project management department establishes a quality management leading group headed by the engineering director. Dedicated personnel are responsible for project quality inspection and support construction monitoring, and promote the creation of excellent project activities.

(2) The unit project implements the responsibility system of the chief engineer, and the chief engineer is fully responsible for the quality, safety and progress of the project.

(3) Each operation team and each operation team has a captain and a work squad leader who serve as quality inspectors part-time, responsible for the quality inspection and control of each construction process.

2. Responsibilities of quality inspectors

(1) Responsible for formulating project quality plans, writing project quality assurance measures, and supervising the implementation of plans and measures.

(2) Regularly provide technical training and quality education to workers to improve their technical level and quality awareness.

(3) Conduct quality inspection, assessment and acceptance of sub-projects in strict accordance with quality acceptance standards and relevant technical requirements.

(4) Organize a project quality inspection every month to summarize experience, find problems, correct mistakes, and commend excellence.

3. Quality system control elements

(1) Construction measurement

Implement the measurement review signature system, the measurement records are true, neat and standard, and the measurements are carried out according to specifications . The measuring instruments are total station and automatic leveling instrument.

(2) Material procurement

A. Conduct market research, select several manufacturers with good production management and reliable quality as pending subcontractors, and include them in the files.

B. Take samples from the pending subcontractor’s products for testing.

C. After passing the test, compare and select the best manufacturer, which will be recognized by the project manager as a qualified sub-supplier and establish a supply relationship.

D. Establish sub-supplier files, keep abreast of quality control of production status, and promote the provision of stable and qualified products, otherwise re-identify qualified sub-suppliers.

(3)Construction process control

A. Strictly implement ISO9000:2000 standards, and supplement and improve the quality assurance system content according to contract requirements to ensure that the project quality rate reaches more than 95% .

B. Use the principles of total quality management to control the quality of the entire construction process. Before the start of construction, organize technical personnel, relevant management personnel, and production backbones to familiarize themselves with the design standards and relevant construction specifications. While formulating the implementation construction organization design, construction details and quality measures will also be formulated. During construction, first of all, we must ensure technical standards and make technical briefings; secondly, we must do a good job in measurement review and test inspection; thirdly, we must strictly enforce construction discipline and labor discipline, and strictly inspect and control the quality of each process to ensure that the project is qualified and excellent the first time. .

C. Earnestly implement the quality management system, including construction drawing review and approval system, technical disclosure system, quality self-inspection, mutual inspection, and special inspection "three inspection system", concealed project inspection and visa system, safety and quality inspection Effective quality management systems such as the evaluation reward and penalty system, the inspection and measurement quality visa system, the sub-project quality assessment system, and the quality accident (hidden hazard) reporting and handling system are specifically implemented in construction activities to ensure that quality control is group-specific. Combination, top-bottom integration, internal and external integration, throughout the entire construction process.

D. Carry out technical training, organize technical research, and solve difficulties in quality management. Set up QC groups and research groups to solve construction technical difficulties and ensure project excellence.

E. Project quality and work quality are linked to distribution. If the quality is unqualified, the work inspection cannot be priced. If a quality accident occurs, penalties will be imposed according to relevant documents.

F. Strengthen the monitoring of key processes in support construction, process the information from monitoring results in a timely manner, and use it to guide cast-in-place construction.

(4) Corrective and preventive measures

A. During the construction process, fully implement the principle of prevention first, and effectively take corrective and preventive measures to prevent the occurrence of substandard products .

B. For quality accidents or common quality problems that may occur during construction, first analyze the causes, identify possible influencing factors, summarize the main influencing factors, and then formulate corresponding countermeasures for the main influencing factors. And assign special personnel to be responsible for implementation, special personnel to inspect, and complete the tasks within a time limit.

(5) Quality records

A. Quality records provide true and accurate evidence that product quality meets specified requirements and that the quality system operates effectively. Therefore, quality records must be true, accurate, timely and complete as required.

B. Quality records shall be established strictly in accordance with the requirements of the construction contract, and a designated person shall be designated to fill in and report.

C. Quality records are archived and managed by the technical department, and the command headquarters organizes relevant business departments to conduct supervision and inspections every month to ensure the continuity and integrity of quality records.

7. Safety assurance measures

1. Establish a safety management system

(1) To ensure quality and construction period, safety must first be ensured. The management department has established Improve the production safety management organization and establish a production safety leading group headed by the Minister of Safety and Quality to be fully responsible for and lead the safety production work of this project.

(2) Implement three-level management of production safety, that is: the first-level management is the responsibility of the safety supervision director, the second-level management is the responsibility of the full-time safety officer, the third-level management is the responsibility of the team leader, and each operation point is responsible for * **Youth League Safety Supervision Post.

(3) Adhering to the policy of "safety first, prevention first, comprehensive management", the director of work safety supervision should regard safety work as the first priority, strengthen safety awareness education for all employees, Strengthen the safety foundation, strengthen the safety guarantee system, implement the safety production responsibility system, strictly implement the "Safety Regulations", conscientiously implement inspections, establish safety rewards and penalties, and effectively control construction safety.

(4) In accordance with the requirements of the "Production Safety Responsibility System" promulgated by our company, implement the production safety responsibility system for managers and operators at all levels, so that they can do their best vertically to the end and horizontally to the edge. Safety work in this position.

(5) Implement a level-by-level safety technical disclosure system. The management department will organize relevant personnel to conduct detailed safety technical disclosures. All personnel participating in safety technical disclosures must complete the signature procedures and save the information. The full-time safety officer of the project management department shall supervise and inspect the implementation of safety technical measures and keep records.

(6) Strengthen construction site safety education

Based on the characteristics of the project, conduct comprehensive safety education for all personnel engaged in management and production, focusing on full-time safety officers, team leaders, and Training and education for scaffolders, crane workers, electricians, welders, mechanics, motor vehicle drivers, etc. in special operations.

A. Construction management personnel and production personnel who have not received safety education are not allowed to work. New workers who have not received third-level education are not allowed to take up the job. Personnel who change types of work or adopt new technologies, new processes, new equipment, and new materials without training are not allowed to work.

B. The safety education, assessment, and re-inspection of operators of special types of work shall be strictly carried out in accordance with the "Regulations on the Management of Safety Technical Assessment of Special Operators". Only after passing the training and assessment and obtaining the operation certificate can you work with the certificate. Special operations personnel who have obtained employment certificates must be registered and archived, their employment certificates must be reviewed regularly, and dedicated personnel must be assigned to manage them.

C. Through safety education, enhance employees’ safety awareness, establish the idea of ??“safety first, prevention first”, and improve employees’ awareness of complying with construction safety disciplines, conscientiously implement safety operating procedures, and achieve : Do not give orders in violation of regulations, do not operate in violation of regulations, do not violate labor disciplines; do not harm yourself, do not harm others, and do not be harmed by others, so as to improve employees' overall safety protection awareness and self-protection capabilities.

(7) Earnestly implement the safety inspection system

The manager must ensure the implementation of the inspection system and stipulate the dates of regular inspections and the personnel participating in the inspections. The management department conducts inspections once every ten days, and the operation team conducts inspections once a day. Non-scheduled inspections should be carried out according to the project conditions, such as before construction preparations, high construction risks, adoption of new processes, seasonal changes, before and after holidays, etc., and there must be leadership. On duty, we will formulate rectification measures for the problems discovered during the inspection in accordance with the principle of "three no-misses", and appoint people to carry out rectification within a time limit to ensure that the principle of "managing production must manage safety" is truly implemented.

2. Determine safety management objectives and key points of safety prevention

(1) The safety objectives of this project are determined to be: no work-related fatalities and serious injuries; and create a safe and civilized construction site that meets standards.

(2) According to the characteristics of this project, the safety precautions focus on the following six aspects:

A. Prevent falling accidents from heights;

B. Prevent accidents from falling from heights;

B. Lifting injury accidents;

C. Prevent electric shock and lightning strike accidents;

D. Prevent mechanical injury accidents;

3. Construction site safety technical measures

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(1) The layout of the construction site complies with the requirements of fire prevention, explosion prevention, flood prevention, lightning protection and other safety regulations. The production, living and office buildings, warehouses, material storage yards, parking lots, repair yards, etc. at the construction site Arrange according to the approved general floor plan.

(2) The roads on the site are smooth, solid and smooth. Signs in accordance with the "Safety Colors" and "Safety Signs" are hung in dangerous places. Red light warnings are set up in pits and holes passed by pedestrians at night. The construction site Set up large safety posters.

(3) Sufficient fire-fighting water sources and fire-fighting facilities should be provided in the production and living areas of the site, and fire-fighting equipment should be managed by dedicated personnel and should not be used indiscriminately. Form a voluntary fire brigade of 15 to 20 people, and all construction personnel should be familiar with and master the performance and use of fire-fighting equipment.

(4) The fire safety distances of various types of houses, warehouses, warehouses, etc. comply with the regulations of the public security department. Inflammable materials are not allowed to be piled indoors. Smoking is strictly prohibited in wood processing plants, warehouses, etc.; Burning debris should be cleaned up at any time. It is strictly prohibited to pile up in places with fire or near them. Safety warning signs should be set up in dangerous areas.

(5) The oxygen cylinder must not be contaminated with grease. The acetylene generator has a safety device to prevent backfire. The oxygen cylinder and the acetylene generator are isolated and stored in a cool place away from open flames.

(6) Temporary power use at the construction site shall be strictly carried out in accordance with the "Technical Specifications for Safety of Temporary Power Use at Construction Sites" JGJ6-88.

A. The installation, maintenance and dismantling of temporary electrical projects must be completed by trained electricians with job certificates. Non-professional electricians are not allowed to perform electrical work.

B. The cable lines adopt the "three-phase five-wire" wiring method. The electrical equipment and electrical lines are well insulated. The suspension height and line spacing of the power lines erected on the site comply with safety regulations and are installed on dedicated power lines. on the pole.

C. The transformer is equipped with a grounding protection device, and its grounding resistance must not be greater than 4 ohms. The transformer is equipped with guardrails and locked doors. There is a dedicated person in charge, and a warning sign "High voltage danger, please do not approach" is hung nearby.

D. The metal shells of various electrical switches and equipment are equipped with grounding or zero protection.

E. The distribution box should be fireproof and rainproof. No debris should be stored in the box. The door should be locked and managed by dedicated personnel.

F. Use rubber-sheathed cables for the power supply lines of mobile electrical equipment. When crossing the driveway, the casings should be laid underground. Damaged cables must not be used.

G. Maintenance of electrical equipment requires a power outage. The handle of the power box switch must be hung with a warning sign saying "Manned operation, closing is strictly prohibited" or a dedicated person should be assigned to supervise it. Any live work must be approved by the relevant department.

H. Do not use bare conductors for power lines erected on site. Temporarily laid electrical lines must not be hung on steel formwork and scaffolding, and insulating supports must be installed.

I. The hand-held lights used at the construction site use a safe voltage of 36V. Individuals are strictly prohibited from pulling or connecting lights or other electrical appliances without the consent of the leader.

J. It is strictly forbidden to use other metal wires instead of fuse wires.

K. Install leakage protection devices on indoor switchboards, and the metal shells of various electrical switches and equipment must be equipped with grounding or zero protection.

4. Safety technical measures for construction machinery

(1) Various machinery operators and vehicle drivers must obtain operation certificates and are not allowed to operate machinery that does not comply with the certificates. , It is not allowed to hand over mechanical equipment to personnel who do not have the machine operation certificate. Establish files for mechanical operators and have dedicated personnel to manage them.

(2) The operator shall strictly implement the inspection system before work, observation during work and inspection and maintenance system after work according to the instructions of the machine.

(3) The cab or operating room should be kept clean and tidy. It is strictly prohibited to store flammable and explosive items. It is strictly prohibited to operate the machinery after drinking. It is strictly prohibited to operate the machinery sick or overloaded.

(4) When parking mechanical equipment at the construction site, choose a safe parking location and have a dedicated person supervise it at night.

(5) For machinery started with a handle, be careful as the handle may be turned upside down and cause injury. Fireworks are strictly prohibited when refueling machinery.

(6) Repair, maintenance, adjustment and other operations on operating mechanical equipment are strictly prohibited.

(7) Command construction machinery operators to stand in a safe place where people can watch, and clearly specify command contact signals.

(8) For machinery using wire ropes, gloves or other objects are strictly prohibited from touching the wire rope during operation. When using the wire rope to drag or pull machinery or heavy objects, keep personnel away from the wire rope.

(9) Lifting operations shall be carried out in strict accordance with the requirements of the "Safety Technical Regulations for the Use of Construction Machinery" (JGJ-86) and the "Safety Technical Operation Regulations for Construction and Installation Workers".

(10) Regularly organize safety inspections of electromechanical equipment and vehicles, investigate and deal with safety issues found during inspections in accordance with the principle of "four no-misses", and formulate preventive measures to prevent mechanical accidents. occur.

8. Design Calculation of Mantang Brackets

1. Calculation of Brackets

The number of rows along the bridge is 118÷1.1=119 rows

The number of cross-bridge nematics is 16, 9×0.6+7×0.9=11.7>11 (the 5m width of the box bottom is calculated as a span of 0.60m, and the 6m width of the wing is calculated as a span of 0.90m) to meet the requirements

The total quantity is: 119×16=1904 pairs

According to the pier height and actual ground elevation (the highest bracket is 5.5m, the lowest is 0.6m, the average height is 3.05m, the span is 1.2m), excluding the jacking and formwork , square wood, etc. can be placed on three-layer brackets. *** is: 1904×3=5712 pairs

2. Calculation of connecting rods

Along the bridge direction: 118×16=1888m

Across the bridge direction: 12×119=1428m

Calculated based on 3 layers corresponding to 4 layers of connecting bowl buckle brackets

The mass of all connecting steel pipes: (1888+1428) × 4=13264m

< p>See Figure 1 for rod connections.

Figure 1 Schematic diagram of rod connection

3. Erection of brackets

According to the design requirements, they were erected separately and jointly according to the design drawings. The first erection was 59m. The second erection is 59m. In order to facilitate construction and eliminate the misalignment of the construction joints during the two pourings, the first erection is 59m. When erecting, properly install longitudinal and transverse scissor braces on the bracket to ensure the stability of the bracket. Steel pipes are used to set up a well-shaped frame at the piers, and the steel pipes are connected to the bowl-shaped brackets to form a whole to ensure the stability of the brackets.

In order to ensure the accuracy of the structural dimensions after construction is completed, the bracket should reserve pre-camber for construction. The pre-camber of the construction is mainly determined by the following factors:

(1) The elastic deformation of the bracket caused by the construction load;

(2) After being loaded, the head of the rod is pressed Inelastic deformation caused by compression of extrusion and unloading equipment;

(3) Subsidence of the support foundation after loading.

See Figure 2 for the installation of continuous box girder brackets in this project.

Figure 2 Longitudinal installation diagram of continuous box girder brackets

Because the box girder branch joints are long, it is difficult to cast and form in one step, and it is not easy to construct. Therefore, each joint is poured in two parts. The mold support is as shown in Figure 3.

Figure 3 Schematic cross-section of the bridge formwork

4. Key points for bracket installation

(1) The foundation must have sufficient bearing capacity before the bracket is upright. The bottom of the upright is Set up spacers to disperse and transmit pressure;

(2) Pre-camber must be reserved for bracket installation.

5. The pre-camber for construction must be reserved for bracket installation

The calculation formula for the reserved camber of the bracket is: f=f1+f2+f3, where f1: elastic deformation of the foundation, f2 : The elastic deformation of the bracket is calculated as f2=12mm based on the stacking preload. f3: The maximum value of the reserved camber for the beam body disturbance is set at the mid-span position, and is distributed to the positions of the columns on both sides in a parabola form. Calculate the camber at each point Reserve the camber value and use the bowl mouth bracket to adjust it.

9. Preloading of full-floor supports

1. Purpose

To eliminate the inelastic deformation of the joints and the inelasticity of the foundation during erection of the supports To obtain a stable bracket from sinking, preloading should be carried out hole by hole. In order to obtain the elastic deformation data of the bracket under load and determine a reasonable construction pre-camber, so that the box girder can obtain the designed elevation and shape after the bracket is removed, settlement observation should be carried out. (The purpose of bracket preloading: 1. Check the safety of the bracket to ensure construction safety. 2. Eliminate the influence of inelastic deformation of the foundation and bracket, which is beneficial to the linear control of the bridge deck.)

2 , Stacking

When preloading the bracket, due to factors such as the stacked items and the operating errors of workers during the construction process, an uneven coefficient of 1.2 is adopted, and sand in woven bags is used as the preloading material. The stacking height of the sand bags is determined according to the change of the beam's self-weight distribution curve, so that the distribution of the preload load is consistent with the distribution of the beam load.

3. Monitoring point layout

Set system measurement points in the stowage area, which are distributed in the middle of the span, 1/4, 1/8, and at both ends of each span. A monitoring point is arranged on the edge of the bottom plate and the center line of the bottom plate of the section. Monitoring points are set accordingly on the ground foundation, and observation points are arranged correspondingly on the support foundation.

Diagram of observation points

4. Monitoring method

In order to find out the plastic and elastic deformation of the bracket under the upper load, the elevation of each control point must be re-measured after 50% and 100% loading, and 100% pre-loading After applying the load and holding the load for 24 hours, the elevation of each control point must be remeasured again. If the measured data after 100% loading and the data measured after holding the load for 24 hours change very little, the cumulative settlement within 24 hours shall not exceed 1.5mm. Only when the design requirements are met, it means that the foundation and brackets have basically settled in place and can be unloaded. Otherwise, the load must be held for preloading until the foundation and brackets have settled in place before the pressure can be relieved. After the pressure relief is completed, the elevation of each control point must be re-measured to obtain the elastic deformation of the bracket and the foundation (equal to the elevation after pressure relief minus the elevation measured after the load is maintained), and the total settlement (that is, the bracket after the load is maintained) is used. Stable settlement) minus the elastic deformation is the inelastic deformation (ie plastic deformation) of the support and foundation. After the preloading is completed, the height of the bracket must be adjusted through the adjustable jacking bracket according to the preloading results.

Settlement observation continues until the entire box girder is poured. Pay special attention to the settlement of the bracket during concrete pouring. If the settlement of the bracket exceeds the reserved settlement amount during pre-pressure settlement observation during pouring, the pouring should be stopped. To prevent accidents from happening.

5. Pre-pressure precautions

Stack the whole hole in layers until the pre-pressure weight of the whole hole bracket meets the requirements, and do not divide the stack into small areas to avoid the occurrence of Uneven settlement; manual stacking is neat and does not pile up randomly.

10. Stress Calculation

1. Load

① Self-weight of reinforced concrete:

Box bottom: 1.5m×25 KN/ m3= 37.5 KPa, (take 1.5m concrete thickness for calculation)

Wing plate part: 0.4m×25 KN/m3= 10 KPa, (take 0.4m concrete thickness for calculation)

② The weight of the formwork (including inner mold, side mold and bracket), based on 5% of the concrete’s own weight, is:

Bottom of the box: 37.5×5%=1.88 KPa

Wing plate parts: 10 ×5%=0.5 KPa

③ Construction load: 2.0 KPa

④ Vibration load: 2.5 KPa

⑤ Impact load caused by concrete tipping: 2.0 KPa

Load combination

Calculate strength: q=①＋②+③＋④+⑤

Calculate stiffness: q=①＋②

2. Bottom form check

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The bottom form adopts a 15mm thick bamboo gluing formwork, which is placed directly on small square timbers with a spacing of L=0.20m. Consider the continuous beam and take the unit length (1.0m) plate width for calculation.

⒈ Load combination

Box bottom: q1=37.5+1.88+2.2.5+2.0=45.88 KN/m

Wing plate: q2=10. 5+2.2.5+2.0=17 KN/m

⒉ Section parameters and material mechanical performance indicators

W=bh2/6=1000×152/6=3.75×104 mm3

I= bh3/12=1000×153/12=2.81×105 mm4

The relevant mechanical performance indicators of the bamboo glue template are in accordance with the Class I regulations of "Bamboo Plywood" (GB13123) The lower limit value of first-class products is: [σ]=90 MPa, E=6×103 MPa

⒊ Bearing capacity check

⑴ Box bottom

Strength

Mmax= q1l2/10=45.88×0.202/10=0.18 KNm

, qualified.

Stiffness

⑵ Wing plate part

Considering that the load here is small, the spacing between square timbers and small flutes is L=0.30m.

Strength

, qualified.

Stiffness

Load:

, qualified.

3. Inspection of square timbers in small corrugated squares

The square timbers are placed on a square with a distance of 0.6m