Guangzhou Steel News: Steel plant design before building a detailed analysis
Guangzhou Steel Advantages
A wide range of uses: suitable for factories, warehouses, office buildings, stadiums, hangars and so on. Both for single large-span buildings, but also for the construction of high-rise buildings or multi-layered.
2, the construction is simple, short construction period: All components are prefabricated in the factory, the scene simply assembled, thus greatly shorten the construction period, a 6,000 square meters of the building, just 40 days to complete the basic installation.
3, durable, easy to maintain: Universal computer designed steel buildings can resist bad weather, and simple maintenance.
4, beautiful and practical: steel buildings clean lines and smooth, modern. Color wall plate a variety of colors to choose from, the wall can be applied to other materials, and therefore more flexible.
5, the cost is reasonable: steel construction, light weight, reduce the basis of cost, construction speed, can be put into operation as soon as possible, comprehensive economic benefits vastly superior concrete construction.
Shortcoming
First, the steel works to produce analysis of quality problems
Steel engineering quality assurance difficult for many reasons, but also very complicated issue both processes improper, there are also problems caused by the breach of process operation, as well as technical problems due to the level of responsibility and cause construction workers, as well as decision-makers errors caused by quality problems.
Presence of (a) steel itself is the problem
A unit in the processing of building a box-shaped column 1200 * 1200 * 60 in the welding process, suddenly found 60mm emerged as tearing the web plate, clearly visible cracks in the plate thickness direction into two half, after NDT testing found the crack depth occurs at a depth of about 3mm, while another batch of the same type in the same cutting board a few parts for testing, found the mezzanine board memory, poor quality rolling is the main cause of quality problems . In the process of welding due to welding stress generated by welding the interlayer material opened. Hence there slab thickness direction tear phenomenon.
Analysis: Due to the use of part of the special nature of the components in the use of the web as a member, along the longitudinal direction of the welded parts in the upper and lower welding formal opening of the full penetration groove force of stiffened plates, due to the presence of the inner plate layered, welding stress generated by welding outwardly thereby releasing tear plate thickness direction.
You can take several measures to deal with the actual situation:
(1), a large number of steel sandwich quality issues that exist within the mill itself produced during the rolling process, has exceeded the national standards requirements, you can send someone to verify the requirements of mills, steel mills, in consultation with a return or exchange cargo handling;
(2), if the number of small sandwich technology sector and may seek the views of the owners, will feedback to the mills, to take remedial measures to construction problems, according to the results of non-destructive testing in question, the site uses gouging all away with more than the depth of their own, and then with an equal strength of welding filler material, after the completion of the surface treatment, after a predetermined time for NDT testing, while samples were taken for the same members, physical and chemical testing, can meet the design specifications continue to use;
(3), under supervision of the witness parts cut off, back into the condition of the plate, Replacement parts for non-load-bearing and non-critical parts or as an auxiliary use, after completion of the prescribed time NDT inspection carried out, make a record.
(B) appear in the construction process in question
Quality problems during manufacture and are more prone to it after a very difficult process mainly special process and important step. General Procedure for quality problems proportion of small. During the construction process in the above, there is a special process of welding, painting, important steps have cutting, assembly.
1, the welding process. This process belongs to the hidden works, one process quality problem is most likely to occur from 2004, a company's product quality report statistics show that in the process of quality problems: because, as a result of the quality of the welding seam failure rates of up to 80 % or more, followed by technical problems due to improper operation processes and operations personnel quality problems caused by weld about 10%, this problem belongs to the direct impact on project quality and quantity of the main issues, so this type of problem must be professional testing company specializing in the use of detection tools to detect, judge it, generally based on the type of defect in the weld into slag, incomplete fusion, such as porosity.
2, coating process. This step is part of covert step for building functional impact on the structure of less than. Also easier to process quality problems. Process quality problems mainly in: paint off a large area of the surface member and a partial loss, the film off the surface of the member, sagging, the film thickness is not enough, uneven distribution of film thickness, film color color larger.
3, lofting cutting step. Before this process belongs to the leading member before processing, its quality to the next step there is a direct impact, and even lead to all parts of scrapped material, this happens, it is very common, so the next expected to enhance process quality control is very important and necessary. This process produces quality problems mainly in: For elongated and thin types of components in the cutting deformation ratio, more powerful; cutting gas cutting surface due to the presence of internal or sheet metal and slag caused by uneven distribution of ingredients appear horse tooth pattern, nodules, deep nicks exceed the standard; gas cutting or sawing parts shrink and does not consider the subsequent process, shape and size of parts caused by excessive; batch process documentation components by mistake which led to the scrapping; material cutting dimensions serious than the standard requirements.
4, the assembly process. This process plays in the quality of the processing member in an important position, which greatly influenced the quality of the procedure, so before the assembly to strengthen the monitoring process is very important. The process produced, the quality of the main problems: the wrong place assembly parts, such as pretending to 3450mm 4350mm; using the wrong parts, should have been # 2 parts assembly parts, assembly # 3 is another member; zero , parts are assembled in the correct position on the error, such as holes panel 45mm originally outward, toward the actual contents of the 45mm; component mounting assembly gap exceeds specifications and technical documentation requirements, the gap of 3mm, 7mm; some zero member has not been corrected on the assembly, after assembly exists no way to eliminate the deformation of the deformation; operatives is the easy way to cut without permission on the part caused excessive size hole location;-chip area is not a table, surface treatment; the paper size error assembly cause mistakes.
(C) the use of
Due to the use of non-standard foam Steel plant, some manufacturers in order to save costs, with the lowest non-fire-retardant materials as fillers, resulting in a fire steel plant personnel can easily lead to the occurrence of casualties.
The above problems are based on finishing the Guangzhou Steel trainees actually encountered in the work is made, for reference, if any questions, please timely communication, correction.
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