Key points of safety control in the construction o

Key points for safety control of cantilever pouring method

1. When cantilever pouring adopts truss hanging basket construction, the following provisions should be observed:

1) before construction, relevant personnel should be organized to carry out safety technical disclosure and formulate safety technical measures. After the hanging basket is assembled, a comprehensive inspection and static load test shall be carried out

2) when zero block construction is carried out on the pier and the cable-stayed bracket is used as the construction platform, safety protection facilities should be set at the edge of the platform. The sidewalk slabs erected between the cable-stayed bracket platforms on both sides of the pier body must be firmly connected

after the formwork of No. 0 block is removed, a part of the platform should be reserved, which can be used for health preservation by using the previous relevant experience of Meibai electronics and other operations

3) the machines and equipment used (such as Jack, pulley, hand chain block with low cycle load cycle, deformation cycle, displacement cycle, steel wire rope, etc.) should be checked, and those that do not meet the regulations are strictly prohibited to use

4) check whether the position and firmness of the embedded parts of the pier body and the cable-stayed steel belt meet the design requirements

5) stop operation in case of strong wind and bad weather

2. During double-layer operation, operators must strictly abide by their respective post responsibilities to prevent omission and falling of iron tools

3. When using the hanging basket, always check whether the rear anchor bar, Jack, chain block, tensioning platform and safety rope are intact and reliable

when the bottom formwork elevation is adjusted, a special person shall be assigned for unified command. Operators should lay a solid scaffold board under their feet and wear safety belts

4. During the installation, walking and use of the hanging basket, the load should be strictly controlled to prevent excessive impact and vibration. If additional facilities (such as rain proof shed, vertical derrick, cold proof shed, etc.) need to be added to the cradle, the structure of the cradle shall not be damaged and its stress form shall not be changed

5. The hanging basket assembly and cantilever assembly are of great danger. When working at heights and deep water, safety should be set, scaffold boards should be fully paved, and temporary guardrails should be set. Operators must wear safety protection articles and be equipped with life-saving facilities as required

6. when using the water tank as the balance weight, its position and water amount should meet the design requirements. Water supply and drainage facilities and methods should be stable and reliable. During construction, regular safety inspection shall be carried out for the above situations

7. Before the bottom formwork swings, it is necessary to carefully check whether the position of the hanging basket, the rear ballast and the installation of the rear boom meet the requirements. First connect the two lifting straps of the upper beam with the lower beam of the bottom formwork, and then swing it after confirming the safety

8. When walking the cradle, it should be carried out slowly, and the speed should be controlled within 0.1m/min in cooperation with Beijing University of chemical technology, Beijing Institute of Aeronautical Manufacturing Engineering and Hangzhou Chaoyang Rubber Co., Ltd. At the rear of the hanging basket, a group of sliding ropes are set respectively to ensure safety. The slideway shall be paved smoothly and straightly without deviation, and attention shall be paid to observation at any time to deal with problems in a timely manner

9. When pouring concrete, the rear end of the cradle truss should be anchored on the completed beam section, and the counterweight should be balanced with the weight of the poured concrete. When the cradle truss is walking and pouring concrete, its stability coefficient shall not be less than 1.5

10. When pouring the concrete of the closure section, pre pressurize the weight at the cantilever end. With the pouring process, the loading should be carried out from top to bottom. When withdrawing the ballast, pay attention to prevent crushing

11. There should be safety protection facilities for roughening the concrete contact surface of the box girder, and the handle of the hammer should be firm. There should be a certain safety distance between operators

12. The construction of sliding cable-stayed hanging basket shall comply with the following provisions:

1) the sliding cable-stayed hanging basket shall be used, and the movable hinge, pin, cable-stayed steel belt, etc. used shall be made of high-strength steel. The material shall be inspected and marked, and must meet the design requirements

2) when the hanging basket is installed or the main beam is in place, the rear anchor and horizontal limit device should be installed first, and then the inclined tension belt can be installed to hang the bottom formwork platform. Strictly prevent the hanging basket from overturning and collapsing

3) before the bottom formwork and side formwork walk along the sliding beam, the diagonal strap and rear sling shall be removed, and the bottom formwork platform shall be lifted, lowered and suspended with a chain fall. At the same time, a safety rope must be added at the position of the chain fall

4) the hanging basket with four diagonal braces shall be used. During the installation and use of diagonal braces, attention shall be paid to the inspection to ensure that the stress is balanced

5) before pouring concrete, the cradle anchorage, horizontal limit, sling lifting and limit device shall be comprehensively checked to confirm that it is safe and reliable before operation

6) after the installation of the main beam and its lifting beam system, a comprehensive inspection and acceptance shall be carried out, and a loading test shall be carried out. Another kind of hanger designed and processed by ourselves is to separate the damp proof course into two thinner layer baskets. Before being used for the first time, the loading test should be carried out according to the maximum construction load

7) when working on the pier cap, scaffolding suitable for the operation needs should be made and installed, and the scaffolding should meet the safety standards

8) before the cradle moves, carefully check the rear anchorage and the stress of each part, and check whether there are hidden dangers and unsafe factors. When walking, pay close attention to whether there are abnormal conditions, and slowly and steadily in place to prevent collapse accidents