Technical measures to prevent formwork and scaffol

Technical measures to prevent formwork and scaffold accidents

1. Strictly control materials

reasonable selection of steel pipes, fasteners and other materials is the primary measure to ensure construction safety. Strengthen the safety investigation system, strictly inspect the materials entering the site, strengthen the acceptance control of the quality of formwork and scaffold materials, and eliminate the use of inferior products

2. Strengthen the management of the construction process

the project department should improve and improve various working systems, especially the preparation of special safety construction schemes for projects with high risks and the expert demonstration system, the safety training and education of operators, the safety technical disclosure system, and the inspection and acceptance system for the quality of steel pipes and fasteners, carefully and timely identify major hazards of the project, implement supervision, and increase the inspection frequency, Effectively curb the occurrence of construction safety accidents

strengthen the management of professional contracting and labor subcontracting units, and effectively eliminate the phenomenon of contracting for management and contracting without care Pay close attention to the special skill training and examination of scaffolders, and improve the professional level of construction teams Strengthen safety education and training, and enhance the safety awareness and self-protection awareness of scaffolders

the project department shall prepare technical measures for construction safety, so that the technical disclosure must be based on written words, and the disclosure procedures must be perfect and must be directly disclosed to front-line operators At the same time, the full-time safety officer of the construction unit must carefully supervise and strictly inspect the construction of formwork and scaffold works, so as to reduce the occurrence of safety accidents

3. Pay attention to the preparation of construction scheme and the design and calculation of support frame

in order to ensure the quality of formwork and scaffold engineering, carry out the preparation of scheme and the design and calculation of support frame according to the technical code for safety of steel tubular scaffold with couplers in construction. The design content should include: determine and draw the calculation diagram of scaffold erection, material selection, load calculation, the strength of bending members such as longitudinal and transverse horizontal bars, and the calculation of anti sliding bearing capacity of connecting fasteners, The stability and axial force calculation of the vertical pole, and the stability and strength calculation of the wall connecting parts; Draw up the installation and removal scheme of formwork and scaffold, etc In order to ensure that the formwork support system has sufficient strength, stiffness and stability, safely support the expected load, and control the support, the Chinese Academy of Metrology summarized and published the calibration mode deformation of 152 frequently used infrared thermometers produced by 49 different manufacturers The formwork design should not only have detailed calculations, but also draw and proofing the detailed structure, indicate the joint method, and mark out the requirements of horizontal step moment and shear support setting

focus on high-risk projects, which refer to the high formwork support system with a height of more than 8 meters or a span of more than 18 meters. A special construction plan should be prepared and experts should be organized to review and demonstrate. The calculation of formwork support load in the plan should be strictly in accordance with the most unfavorable principle, including the dynamic load caused by pumping concrete The construction site shall set up the formwork support system in strict accordance with the provisions of the scheme, set up cross braces and sweeping rods as required, and determine the access and location of the upper and lower construction faces

4. Requirements for main technical measures

(1) the construction load on the operation layer shall meet the use requirements and shall not be overloaded It is not allowed to fix the formwork support, wind rope, delivery pipe for pumping concrete and mortar on the scaffold, and it is strictly prohibited to hang lifting equipment

(2) during the use of the scaffold, it is strictly forbidden to remove the following components: longitudinal and transverse horizontal rods, longitudinal and transverse sweeping rods at the main node; Wall attachment

(3) excavation operations shall not be carried out on the scaffold foundation and its adjacent places

(4) the U-ring of the cantilever steel pipe scaffold should be embedded. 4. During the operation of the unit, the steel price should be strictly controlled. After the downturn, the two should be in a straight line When erecting the first pole on the steel beam, at least 2 people should cooperate. After erecting the pole, quickly bind the sweeping pole to prevent the pole from toppling For safety, add a steel wire rope on the outside of the steel beam and pull it upside down on the embedded ring of the upper outer beam The erection height of a cantilevered section of steel pipe scaffold with profile steel base shall not exceed 24 meters Cross bracing and diagonal bracing shall be erected synchronously with the upright and horizontal poles, and the lower end of the bottom diagonal pole must be supported on the base plate During construction, the verticality of the upright shall be checked frequently, and the vertical deviation of the full height shall not be greater than 1/400 of the frame height, and not greater than 100mm Control the torque of fastener bolts: use a torque wrench to control the torque of fastener nodes at 40 ~ 65n m.

5. Safety technical measures for erection and removal of high formwork

(1) comply with the relevant provisions of the safety technical specifications for work at heights, and the length of the cross bar should not be less than three spans (considering the role of the tie beam); The cross bar shall be connected by butt fasteners, which shall be staggered, that is, the joints of two adjacent cross bars shall not be set in the same or the same span, and the distance between two adjacent joints of asynchronous or different spans in the horizontal direction shall not be less than 1000mm; When butt fasteners are used, when rotary fasteners are used for connection, the erection length of the cross bar shall not be less than 1 meter, and three rotary fasteners shall be set at equal intervals for fixation

(2) the formwork support is equipped with vertical and horizontal sweeping rods. The sweeping rods should be fixed on the upright rods at a distance of not more than 200 mm from the ground with right angle fasteners. When the foundation of the upright rods is not at the same height, the vertical sweeping rods at the top must be extended to the bottom for two spans to be fixed with the upright rods

(3) the butt fasteners on the vertical pole are staggered, that is, the joints of two adjacent vertical poles are not set in the synchronization, and the staggered distance between the two separated joints of one vertical pole in the synchronization should not be less than 1000mm in the direction of high loading rate or loading degree of equal stress rate; The horizontal steel pipe bearing the wood brace at the bottom of the plate shall not have cantilevered steel pipe, and a vertical rod must be added at the end When the concrete construction of the middle column is completed, the full hall frame and the column can be connected into a whole in time to enhance the overall stability of the full hall frame

(4) the top cross bar is reinforced with double fasteners to prevent the cross bar from sliding; The number of vertical poles crossed by each diagonal bracing is determined by the inclination angle between the diagonal pole and the ground between 40 and 50; A pair of diagonal braces must be set at both ends of the outer facade of the formwork support, and should be set continuously from bottom to top. The clear distance between the middle diagonal braces should not be greater than 10 meters; The extension of diagonal bridging rod shall be overlapped, and the overlapping length shall not be less than 1 meter, and it shall be fixed with 3 (or more) rotating fasteners; The diagonal bridging rod shall be fixed on the cross bar or vertical bar compared with it with rotating fasteners; The allowable vertical deviation of formwork pole support every 2 meters high is 15mm; Reliable temporary anti overturning facilities must be provided for the formwork and its support system during installation

(5) a working ladder should be set up on the construction site, and the operators should not climb up and down the formwork Sufficient operating platforms and safety protection shall be provided for the high-altitude edges on the high formwork. Effective drainage measures shall be taken for the ground within the high formwork, and it is not allowed to erect the unfixed column of the probe plate

(6) when removing the formwork, the concrete strength must meet certain requirements. It is forbidden to remove the bottom formwork and support when the concrete does not meet the requirements of the design strength to prevent collapse accidents The principle of top-down shall be strictly followed in formwork removal. The non bearing formwork shall be removed first, and then the bearing formwork. It is forbidden to throw the formwork