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Let's talk about itHuaxia tower craneThe normal service life

Huaxia tower crane is a kind of jib crane. Its boom is located at the top of the vertical tower. Tower crane, also known as tower crane, is a major crane in modern engineering construction. Next, the editor will introduce the normal service life of Huaxia tower crane in detail.

The calculated stress of the main bearing structure of Huaxia tower crane increases due to corrosion or wear. If it exceeds 15% of the original calculated stress, it should be scrapped. If the corrosion depth of Huaxia tower crane does not meet the calculation conditions reaches 10% of the original thickness, it should be scrapped. The main bearing structures of tower crane, such as tower body and boom, should be scrapped when they lose their overall stability. If they are partially damaged and repairable, the bearing capacity of the original structure cannot be reduced after repair.

When cracks appear in the structural parts and welds of Huaxia tower crane, measures such as strengthening or re-welding should be taken according to the stress and crack situation, and its development should be regularly observed in use. Tower cranes that cannot be cleaned up should be scrapped.

　　Huaxia tower craneThe normal working life of the main load-bearing structural components shall be calculated according to the requirements of the instruction manual or the structural stress state of the structural working level and stress cycle level specified in the instruction manual. If the instruction manual does not specify the normal working life, working level, etc., and cannot be determined by the tower crane manufacturer, the main load-bearing structure of the tower crane in normal use shall not exceed 1.25x 10 5 working cycles.

Matters needing attention in the construction of foundation cap of Huaxia tower crane

Huaxia tower crane is a kind of lifting machinery that can realize the overall transportation of heavy objects. The working height is generally tens of meters to hundreds of meters, and the working radius can reach tens of meters. Now the number of tower cranes is also increasing. Next, the small series introduces the construction of tower crane foundation platform.

During the construction of tower crane foundation bearing platform, the natural slope of 1:1 shall be adopted for earthwork excavation. Considering that the earthwork in the upper pit of the working face is 2.0 high, step excavation shall be adopted. Overexcavation of tower crane foundation is strictly prohibited. Therefore, special attention shall be paid to the construction of tower crane foundation and subsequent tower bearing platform. Before earthwork excavation, the builder shall make detailed technical disclosure to the excavating personnel to determine the top line of the slope, the earth excavation of the bearing platform shall be stopped by mechanical excavation to 0.3m above the bottom elevation of the bearing platform cushion layer, and the remaining earth shall be excavated manually.

During the excavation of tower crane, attention shall be paid to the protection of engineering piles. Earthmoving machinery shall not collide to prevent damage to the pile body. After foundation excavation, the foundation trench shall be checked and accepted in time. After the foundation trench is qualified, the next working procedure such as cushion layer shall be carried out in time to avoid soil exposure as far as possible, prevent soil moisture evaporation loss, soil volume expansion or soil soaking due to rain, and cover the foundation with plastic film and canvas when necessary.

　　Huaxia tower craneThey are all on the first floor of the basement, so the basement shall be drained in the foundation construction stage. Before the pile cap construction, the pile foundation shall be inspected and the structure of the top of the pipe pile and the pile cap shall be treated. According to the instructions of the tower crane, accurate embedded parts and lightning protection downlead shall be embedded together. The formwork shall be firm, the concrete shall be poured and formed at one time, vibrated and compacted. The concrete surface shall be leveled.