Safety technology of disassembly and assembly of tower crane

I. Technical inspection before disassembly and assembly

Before disassembly and assembly, a comprehensive inspection shall be conducted to prevent any hidden danger caused by negligence and ensure safe operation.

1, check whether the subgrade and concrete fixed foundation meet the technical requirements.

2. Carefully check the mechanism, components, structural welds, bolts, shafts, hoisting mechanisms, wire ropes, hooks, spreaders, electrical equipment and lines of the tower crane, and solve the problems immediately when found.

3. Check the hydraulic cylinder and tubing of jack-up hydraulic system, jack-up jacket structure, guide wheels, lifting shoes and climbing claws, and handle the problems in time when found.

4. Check the main and auxiliary ground anchors, lifting wire rope of landing tower, braking system of lifting mechanism, etc. The rotating tower body method is adopted for disassembly and assembly, and it can be used only after it is confirmed.

5, tools, seat belts, helmets, etc. Those used by dismantlers should be thoroughly inspected, and those unqualified should be replaced immediately.

6, check the auxiliary machinery in the demolition work, such as cranes, transport vehicles, etc. Must have good performance, technical requirements can ensure the need of disassembly.

7. Check the relevant conditions of the demolition site, such as whether the power supply, transportation road and work site are ready for demolition.

8. The setting of safety supervision posts and the implementation of safety measures meet the requirements.

2. Safety technology in disassembly and assembly operations

1, the disassembly and assembly of tower crane must be carried out during the day. If you need to speed up the progress, you can do some assembly work at night with good lighting conditions, not in strong winds, dense fog, rain and snow.

2. During installation or disassembly, the site must be kept clean and orderly, and sundries shall not be piled up, so as not to interfere with operation and affect safety. Wood square must be placed under the metal structure of tower crane to prevent damage to the structure or structural deformation.

3, installation and erection of steel wire rope and its fixation must conform to the standards and meet the installation requirements. Temporary facilities such as ground anchors must be firmly constructed, especially before disassembly. The ground anchors used during installation must be carefully checked to ensure that they are still solid and reliable.

4. Before assembling or installing the parts one by one, the integrity, connection, wire rope threading and electrical circuit of the parts must be thoroughly inspected.

5. In the erection process, the stress on the structure and steel wire rope is the most unfavorable in the initial stage of tower erection, and decreases gradually with tower erection. In the process of dismantling the tower, the stress is the greatest when the tower is about to lie down completely. Therefore, when the tower starts to lift or is about to fall, it must be done slowly, and the inspection and observation of the main components should be strengthened.

6. Always keep the crane balanced when removing the jib and counterweight. It is forbidden to remove only one arm and interrupt the operation.

7. In the process of disassembly, if it is impossible to continue the operation due to sudden power failure, mechanical failure, sudden weather change and other reasons. Or when the operation time has come to a stop, the components installed and disassembled by the crane must reach a stable state and have been locked firmly, all structural components have been firmly connected, and the center of gravity of the tower top is at the center of the four sides of the tower bottom support. Only after inspection and confirmation can the operation be stopped.

8. During installation, the specified bolts, pins and other connectors shall be used according to the installation requirements, and reliable locking or protection devices shall be provided. When tightening bolts, the specified pre-tightening force should be added. Wire rope installation should strictly implement GB 5972-86 "Operating Rules for Inspection and Scrapping of Wire Ropes for Hoisting Machinery".

9. When installing the crane, the traveling limit device of the cart and the buffer of the limit device must be installed firmly and reliably. And assemble all parts of railings, platforms, chains, handrails, fixers and other safety protection devices.

10. When disassembling a crane that cannot be disassembled by normal methods due to damage, there must be a disassembly plan approved by the technical safety department to ensure safety.

1 1, installation procedures, auxiliary equipment, rigging, tools and ground anchor construction, etc. , should be handled in accordance with the provisions of the machine manual or refer to the standard installation process.

Safety technology of three-jack-up high-altitude operation

1, hydraulic system

(1) Hydraulic oil must conform to the varieties and labels specified in the original manual. If it is necessary to substitute, its performance must be the same as or similar to the original variety and label, and it is not allowed to substitute at will, nor to mix two different hydraulic oils.

(2) The hydraulic oil and hydraulic system must be kept clean and free of impurities such as dust, moisture, metal chips and rust. The amount of oil in the oil tank should be kept at the normal oil level. When changing oil, the hydraulic system should be thoroughly cleaned and new oil must be filtered. The container containing hydraulic oil must be kept clean, and the inner wall of the container shall not be painted.

(3) The hydraulic oil pipe joint shall be firm and shockproof, and the hose shall not be sharply bent or twisted, and shall not collide and rub with other pipes or objects.

(4) The inlet, outlet and rotating direction of the hydraulic pump shall be consistent with the signs. Do not knock when removing the coupling.

(5) The hose connection of hydraulic cylinder shall not be loose, and the entrances and exits of valves shall not be installed backwards. The flange screws shall be tightened with pre-tightening force as required.

(6) When the hydraulic pump starts and stops, the relief valve should be unloaded, and the regulating pressure of the relief valve should not exceed the maximum pressure of the hydraulic system.

(7) The connection seal of each part of the hydraulic system must be reliable without leakage, and the interlock device must be verified.

(8) When opening the air valve or checking the leakage of the high-pressure system, don't face the direction of the injection port.

(9) When slight or partial blowdown occurs in the high-pressure system, it shall be unloaded and overhauled immediately, and the blowdown shall not be checked or blocked by hand.

(10) When the hydraulic system fails or has an accident, it must be unloaded before it can be inspected and adjusted.

2, jack-up operation

(1) Before jack-up, it is necessary to check the connection of various parts of the hydraulic jack-up system, adjust the gap between the guide roller of jack-up jacket and the tower, then loosen the cable with a length slightly greater than the jack-up height and fasten the cable drum.

(2) Jack-up operation must be carried out under the command of special personnel. Non-operators are not allowed to board the jack-up jacket console. Only one person is allowed to operate the operating room, and strictly obey the signal command.

(3) Jack-up should be carried out during the day, and under special circumstances, there should be enough lighting for night work.

(4) When the wind force is above level 4, jack-up operation is not allowed. If the wind suddenly increases during the operation, the operation must be stopped immediately, and the upper and lower towers are firmly connected.

(5) During jack-up, the boom and balance block must be in a balanced state, and the rotating part should be braked. Operations such as rotating the boom are prohibited. If any fault is found in the process of jack-up, the jack-up must be stopped immediately for inspection, and the jack-up can be continued after the fault is eliminated. If the fault cannot be eliminated in a short time, the jack-up jacket should be lowered to its original position and the connecting bolts should be tightened in time.

(6) When removing the connecting bolt (pin) between the tower and the standard section of the tower body, if it is difficult to remove and assemble the last bolt, the diagonal bolt (nipple) should be reinserted and other measures should be taken. Do not loosen the bolt (pin) by rotating the boom.

(7) During jack-up, before the next action, it must be confirmed that the jack-up bracket is firmly in place.

(8) During the jack-up operation, pay attention to the pressure change of the hydraulic system at any time, and check and adjust it in time if there is any abnormality. There must also be a special person to measure the verticality change of the tower with theodolite and make records.

(9) After jacking to the specified height, the tower must be attached to the building to continue jacking.

(10) When jacking during disassembly, the precautions are the same as above. However, the anchorage device shall not be dismantled in advance, and it can only be dismantled when the anchorage device descends to the attachment joint.

(1 1) After jack-up installation and disassembly, the connecting bolt pin shall be fastened according to the specified preload, the guide wheel of jack-up sleeve shall be in good agreement with the tower, the left and right joysticks of hydraulic system shall be in the middle position, and the power supply of hydraulic jack-up mechanism shall be cut off.

4. Safety technology of accessory operation

1, tower crane attached to the building, its stress intensity must meet the requirements of tower crane attachment.

2. According to the total construction height, structural characteristics and construction progress requirements of this project, the following attachment scheme is arranged: two anchorages are set, the distance between attachment brackets is 1500m, and angle steel attachment rod system and corresponding attachment technology are adopted.

3. When installing the attachment frame and the attachment rod, use theodolite to observe and adjust the attachment rod to ensure the verticality of the tower.

4. The attachment frame should be set at the standard joint of the tower as far as possible. When the tower is tightened, diagonal braces should be set to reinforce the tower.

5. With the jack-up and assembly of tower section, the added anchorage should be attached to the building in time. The free height of the tower above the anchoring device shall generally not exceed 40m.

6. When multi-channel anchorage devices need to be set in the construction of super high-rise buildings, the lower anchorage devices can be transferred to the upper part for use. But the distance between the first anchorage and the tower crane foundation shall not exceed 50m. The arrangement of each anchoring device shall comply with the relevant provisions in the instruction manual.

7. The place where the attached bearing is laid must be reinforced, and the label of concrete should be appropriately improved. When connecting, the structural strength of the connecting bracket must meet the design strength. Attached bearings are set on the cast-in-place concrete inner wallboard, and supports and steel bars must be set between wallboard (this span and adjacent spans). (When the attachment bearing is fixed on the floor, steel bar support should be set between the two floors. ) Attached bearings should be fixed firmly, and the gap between them and the building structure should be tightly plugged.

8, in the process of operation, must often check the anchoring device, found loose and abnormal situation, should immediately stop the operation, failure is not completely eliminated, shall not continue to use.

9. When disassembling the crane, the corresponding anchoring device should be disassembled together with the landing process. It is forbidden to remove the anchoring device before falling off the tower.

10, it is forbidden to install or dismantle anchoring devices in strong winds of magnitude 6 and above.

1 1, the installation, disassembly, inspection and adjustment of the anchoring device shall be the responsibility of the special person, and the safety belt and helmet shall be worn during operation, and the relevant provisions of the Safety Operation Regulations for Aerial Work shall be observed.

Safety technology of climbing operation

(1) Climbing operations should be carried out during the day. When the wind exceeds level 5, the operation should be stopped.

(2) When climbing, we should strengthen the connection between the upper and lower floors, and strengthen the connection between the upper and lower floors. If there are faults and abnormal conditions, stop the machine immediately for inspection. Don't continue climbing unless the fault is eliminated.

(3) During climbing, lifting, turning and luffing are prohibited.

(4) After the tower crane climbs to the specified height, it shall immediately pull out the supporting beam or leg of the tower foundation and fix it on the floor through the climbing frame to bear the vertical load from the upper part of the tower crane.

(5) The tower crane is attached to the floor through the guide device, wedge and climbing frame. Therefore, the guide device should be pushed or wedged immediately after climbing to bear the horizontal load. The attachment spacing of internal climbing tower crane should generally not be less than 3 layers.

(6) For floors with climbing frames, all floors below should be temporarily reinforced with columns. The two floors below the tower crane foundation supporting beam are temporarily strengthened with columns.

(7) After each climb, the holes left on the floor must be immediately closed with reinforced concrete.

(8) After the tower crane completes the climbing operation, it is necessary to check whether the attachment is firm, whether the climbing frame is fixed, whether the base support is fastened, and whether the temporary support on the floor is appropriate. , and confirm that there are no remaining problems, before lifting operation can be carried out at another floor height.

Six safety technical measures

1, on-site construction technical director made a comprehensive inspection of tower crane, made a comprehensive inspection of safety protection in installation area, and organized all installers to learn installation scheme. The tower crane driver conducted a comprehensive inspection of the mechanical structure of each part of the tower crane, and the electrician conducted a comprehensive inspection of the circuit, operation control and braking system. The hoisting commander shall comprehensively inspect the prepared machines, tools, equipment, ropes, shackles and mooring heads.

2. Participants must hold relevant certificates, wear safety helmets, fasten safety belts when working high above the ground, and wear non-slip shoes with rubber soles.

3. Listen to the weather forecast in time, stop working when the wind is above 4 or when it rains heavily, and take emergency preventive measures.

4, aerial work tools shall not be misplaced, shall not be thrown.

5. All staff members are not allowed to press the button or toggle the switch without authorization.

6. It is forbidden for the installer to work after drinking, and it is forbidden to cross up and down without protection.

7, homework at night must have enough lighting.

8. It is forbidden to install personnel within 20 meters centered on tower crane, and the site safety is responsible for the alert.

9, obey the unified command, clear contact methods and signals.

10, the driver uses technical disclosure before taking up his post, and takes up his post after passing the sampling inspection.

Main points of using seven tower cranes

1, the use of tower crane, should comply with the norms and regulations issued by the competent department of the state. At the same time, we should also abide by the relevant provisions in the instructions.

2. The working environment temperature of tower crane is -20~40℃, the maximum working wind pressure is 250N/m2, and the maximum non-working wind pressure is 700N/m2. When the wind speed exceeds 6, it should stop. When a storm warning is issued, the tower crane should be suspended and fixed with a cable wind rope.

3. Keep all safety devices on the tower crane sensitive and effective. It should be checked once a month. When a failed safety device is found, it must be repaired or adjusted in time. After all safety devices are properly adjusted, it is forbidden to touch them without authorization and seal them (such as wax seal or lead seal) to prevent unauthorized adjustment.

4, tower crane must have a reliable grounding, all electrical equipment shell should be firmly connected with the body, check once every six months.

5, power supply voltage should reach 380V, its range shall not exceed 20V ... Distribution box should be set near the tower crane, power switch should meet the requirements. Cable reels must be flexible and effective, and towing is not allowed.

6. When this tower crane works near the medium-wave radio broadcasting transmitting antenna, all operators who contact the hook should wear insulating gloves and shoes.

7. During maintenance and overhaul, the power supply of the tower crane should be cut off, and warning signs "No switching on when someone is working" should be hung on the distribution box and iron shell switch.