Key points for construction of steel bar dense str

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Key points for construction of steel bar intensive structures in industrial devices

[Abstract] construction in industrial devices often involves structures with complex structures and dense steel bars. Although the forms are the same, there are great differences in the internal reinforcement of the structure according to the process characteristics of the device, production capacity, geological conditions of various regions, seismic fortification requirements, etc. Therefore, in the construction process, we must thoroughly analyze, study and prepare a feasible construction plan to ensure the orderly construction

[Key words] key points of reinforcement intensive construction of industrial devices

in petrochemical 2, metal tension, contraction, twists and turns and change experiments: in the construction of industrial projects, we often encounter reinforced concrete structures with complex structural forms and dense reinforcement. For example, the frame type oil washing tower foundation in the ethylene plant, the large frame type compressor foundation in the air separation plant, etc. These frame type foundations are designed with dense reinforcement due to the large load of the upper equipment in the use process, or its upper part is power equipment, or considering the local seismic fortification level and other conditions, which is a typical reinforcement intensive structure in industrial plants. In addition, the foundation bolts or bolt holes required for equipment installation form a certain construction difficulty. Carefully analyze the z-axis drawing of the mast mechanism column to clarify the design intent. Fully considering the problems encountered in the construction is the premise of normal and orderly construction

    1. Determining the construction procedure

distinguishing the structural level is the premise of understanding the design intent and arranging reasonable construction procedures

frame type equipment foundation (most of which are quench oil tower and silo foundation), the usual force transmission mode is: equipment load → base ring beam → inclined beam → frame beam (primary and secondary beams are set according to the direction of the frame) → frame column → foundation slab → foundation. The force transmission mode of compressor foundation is relatively simple. After the load is transmitted to the foundation top plate, it is transmitted from the column to the bottom plate, and finally all the loads are carried by the foundation. Because hidden beams (beams with the same height as the top slab) are usually hidden in the internal reinforcement of the thick top slab, it is necessary to distinguish between primary and secondary during construction. As shown in Figure 1 and 2

Figure 1 Distribution of foundation base plate and column

Figure 2 distribution of beams at all levels of foundation top plate

according to the force transmission path and structural distribution level of the above analysis, the sequence of reinforcement laying can be obtained: frame main beam → frame secondary beam → inclined beam → ring beam → plate

    2. Self review and joint review of construction drawings

2.1 problems that should be paid attention to in the self review of drawings

during the calculation of this kind of structure, the structural design of ring beam, inclined beam, frame beam, column and bottom plate shall be carried out in sequence according to the load transmission path. During the self-examination of drawings, we made clear the following aspects of this structure, and analyzed the relationship between several fault levels that will appear in the equipment

1) height of beams at all levels after the completion of concrete pouring, the entire section (specifically the beam height) should be the same height. If the steel bars are cut and processed according to the single-level design, after the steel bars are stacked with each other, it is bound to exceed the design elevation; In order to achieve the section size and top elevation required by the design, it is necessary to ensure the same height of beams at all levels, and the two contradict each other

2) steel bars are superimposed on each other in this structure, and the diameter of steel bars is φ 28~ φ 36mm is common. Reinforcement is generally more than 2 floors. For example, in the 600000 T/a ethylene reconstruction and expansion project of Yangzi Petrochemical: the foundation of the 101e quench oil tower in the quench area, and the bottom reinforcement of the frame beam is 3 layers, φ 32mm, as a new independent high-performance electric vehicle brand facing the future of the company, has two layers of top ribs, φ 32mm; Reinforcement of inclined beam and ring beam φ 28mm, with two layers arranged above and below. After the reinforcement is stacked, if the main beam is taken as the standard, it will be higher than: 32+12+28+12+28=112mm, which will not only affect the equipment installation and process piping, but also increase the structural load

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