L48A1 Mast SectionWorking procedures and safety rules for tower crane installation
Tower crane installation rules
L48A1 Mast Section：
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This paper will explain the installation rules and methods of the tower crane in detail from the aspects of preparation, installation of the base plate, installation of the standard section, support erection, tower top erection, cab erection, balance arm erection, crane arm erection, balance weight hoisting, etc.
1. Preparation
A. determine the erection position of the tower crane. The principle is to maximize the construction capacity of the tower crane and facilitate the access, installation and disassembly of the tower crane.
B. select appropriate foundation type. The ballast and concrete foundation shall be made in advance and reach the grade, and the foundation ground endurance shall not be less than 20t / m2.
C. open the site access, clean the site and level the foundation plane.
2. Erection procedure
< 1 >, baseplate installation: assemble the base frame on the foundation, level the foot and lock the anchor fixing bolts.
< 2 >, standard section installation
A. place 1 standard section on the underframe and fix it.
B. align the balance arm with the standard section of the tower body and anchor it well.
C. put the suspender through the heavy rope and fix it on the main rotating rod near the end of the balance arm of the standard section, and fix it with the fixture.
D. lift the second standard section to the first standard section and fix it, and then lift the boom 1m. Pay attention to fix the guide fixture on the upper part before lifting.
E. lift the support section to the second standard section and fix it, and then lift the suspender for one section.
F. install three diagonal bracing rods, and temporarily do not install the fourth one at one end of the fixed suspender.
G. lift one section of reinforcement section to the upper part of support section and fix the distance of lifting one section of suspender. At this time, the suspender is separated from the supporting point of the supporting section.
H. install the fourth diagonal support, and then use the theodolite to correct the verticality of the tower body to 1 / 1000.
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3. Erection of lower turntable and slewing support: assemble the slewing mechanism on the upper turntable and fix it on the slewing support with suspender at one time. Note that the cantilever height of suspender shall not exceed 2.5m.
4. Tower top erection
A. align the main chord at one end of the fixed section of the upper turntable with the suspender, put the fixed clamp on the main chord of the fixed section together with the suspender, and raise the suspender to the highest position of the tower body for fixation.
5. Cab erection
A. drop the suspender so that the upper end of the suspender is 2.6m higher than the top of the tower body. At this time, remove the fixed card on the fixed joint and use the short fixed card on the fixed tower body instead.
B. the slewing mechanism is electrified to align the front section of the fixed section with the suspender.
C. the lifting cab is fixed on the right support of the upper turntable, and the upper part is connected with the fixed joint by bolts.
6. Balance arm erection
A. drop the suspender below the lower turntable, fix the horizontal end of the suspender close to the tower body, and take up the lifting rope,
B. at the top of the tower, at the front end of the balance arm and the balance weight hanger, fix one 1t pulley respectively, put on the lifting rope, and finally fix it at the front end of the balance arm, and bolt a slip rope at the end of the boom.
C. start the lifting mechanism, slowly tension the lifting rope, slowly pull up the balance arm, so that the intersection point of its heel is close to the intersection point of the fixed joint. When the two intersections are aligned, pin the pin shaft. When lifting the boom, slide the rope to avoid the balance arm turning and collision with the boom.
D. loosen the lifting rope at the heel of the balance arm. Fix the lifting rope on the tower top. Start the lifting mechanism to slowly tighten the lifting rope, and at the same time, tighten the sliding rope. Pull the boom up an angle. Connect the tie rod of the flat cross arm and pin the pin shaft.
E. after the railings are connected, slowly loosen the brake, loosen the lifting rope, and slowly tighten the pull rod.
F. lift two balance weights and place them at the tail of balance arm.
7. Boom erection
A. the boom shall be butted on the ground and installed with the crane sports car, and the luffing steel wire rope shall be wound and tightened to fix the sports car on the boom head section. Install the boom front and rear tie rods and fix them on the top chord with wire.
B. a pulley is fixed at the heel of the boom and at the top of the tower. In the fifth section, two 1t pulleys are fixed at the front of the boom, and the sliding rope is bolted at the rear of the boom.
C. put the lifting rope through the lifting pulley on the tower top, pass through the 1t pulley at the root of the boom, fix it up to the top of the tower, and remove the pulley block at the front of the fixed joint.
D. start the lifting mechanism, slowly tighten the lifting rope, pull up the boom, align the intersection point at the root of the boom with the fixed intersection point, and pin the pin shaft. Pay attention to slip the rope to prevent the reverse of the boom from colliding with the tower body.
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E. remove the lifting rope, exit the heel pulley, thread the lifting rope around the pulley block of section 5 of the boom and the pulley block at the top of the tower according to the ratio of 4, and finally fix it on the tower top.
F. slowly tighten the heavy rope of the device, and at the same time tighten the sliding rope, so that the boom is pulled up through the dead point, and then the boom is pulled up to an angle to stop. Connect the boom front and rear pull rods and pin the pin shaft.
G. loosen the brake, slowly lower the boom and slowly tighten the pull rod.
H. remove the lifting rope and recover the drum. Remove the pulley block from the tower top and boom. Install the pulley block at the front of the fixed section.
8. Hoisting of balance weight.
9. Connect all power supplies, safety devices and rotary locking devices.
10. The wire rope shall be wound and finally fixed at the head end of the boom in the order of pulley, fixed joint, crane sports car and fishing hook on the top of the tower.
11. No load test 3 times.
12. Rated load test
A. three times for maximum amplitude, lifting weight, lifting, turning and luffing respectively.
B. amplitude, lifting weight, lifting, turning and luffing three times respectively.
During the above experiments, adjust the moment, lifting weight limiter, height, luffing, slewing limiter, etc.
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