This paper analyzes the key points of construction management of large steel structure workshop from the aspects of preparation before construction, steel structure production and installation process, and points out the key points and methods of construction management of steel structure workshop.

1、 Supervision (Management) control points in construction preparation stage

(1) Set up project management team.According to the characteristics of the project, personnel with experience, strong technical ability, strong sense of responsibility and coordination must be selected, and professional support should be provided. In particular, the selection of the chief inspector should have good professional quality and service consciousness. At the same time, the role of each functional department of the unit should be brought into full play, and the appropriate supervision organization form should be selected according to the characteristics of the project.

(2) Be familiar with the drawings, specifications and design requirements, preside over the drawing review and design disclosure, understand the construction unit, and prepare targeted supervision planning, supervision implementation rules, management scheme, etc.The management personnel must be familiar with the drawings and design ideas, master the specifications and atlas, and understand the requirements of the management rules.Understand the use function requirements and design intention of steel structure, do a good job in professional “design check”, understand the project operation system and management system of the construction unit, supervise and urge the implementation of quality management system, technical management system and safety management system to personnel, check their work certificates, check the post certificates of main operators, and conduct a thorough investigation on the team quality.In order to ensure the smooth progress of the project, management requirements should be put forward.

(3) Strengthen the inspection and audit on the qualification of subcontractors and steel structure processing and manufacturing plants.Strengthen the inspection of the steel structure manufacturing plant, mainly investigate the equipment capacity, technical ability, process design ability, process flow, process inspection, inspection means and conditions, quality management system, welding procedure qualification, assembly conditions, etc. for units with insufficient conditions, rectification shall be proposed within a time limit. The construction unit shall cooperate with and supervise the rectification, and sign the qualification examination after the rectification is in place.Nuclear report and commencement order.It is necessary to review the quality assurance system and quality inspection system of the subcontractor, and check whether the self inspection equipment and its use meet the requirements of the project.

(4) Carefully review the construction organization design and construction scheme of the construction unit to see if it can meet the particularity of the project, especially the hoisting scheme. It is necessary to analyze according to the site conditions the access and operation position of heavy lifting equipment, the hardening of the site, etc.; the rationality of the site construction layout, the construction guarantee measures under the quality, progress, safety and special conditions, and the machinery used For equipment, instruments, inspection tools, etc., which can not meet the requirements of the project, it is necessary to urge the correction within a time limit, the supplementary technical measures should be implemented, the use of new technology, new materials and new technology should have process test and appraisal opinions, the construction unit should be urged to improve and strengthen the control of various management objectives, and the responsibility system at all levels should be implemented and effectively operated.

2、 Control points of supervision in construction stage

(1) Check the quality assurance certificate, inspection report and on-site sampling retest report of all kinds of raw materials, and only those qualified can be used in the project.It is impossible to send supervisors with strong skills, experience and management ability to live in the production site, because it is impossible to send too many on-site personnel, so the quality requirements are very high.

(2) The manufacturer should have the production process experience of this kind of medium-sized steel structure, otherwise, the process test and evaluation shall be carried out, the design requirements shall be analyzed, and the reliable process shall be used to make the sample plate, and the batch production shall be carried out according to this when feasible.Main inspection of fabrication: surface quality of blanking plate and steel plate, welding process (welding flux shall have quality guarantee certificate, drying record, personnel certificate, weld height, flaw detection inspection), friction surface treatment, component size inspection, pre assembly dimension gap, paint film thickness and coating materials, etc.

(3) Construction site inspection: the certificate of high strength bolt, torque coefficient, tightening axial force, retest report (torque coefficient and anti sliding test of matching friction surface) members shall be inspected on site (mainly to check the size, number and deformation). During the construction, all beams and columns must be mobilized. The key points of on-site installation quality inspection are as follows: the tightening surface of beam column top is mainly inspected, and the torque wrench is required to be checked first.The verification certificate of hand (electric) and the flatness of the friction surface; secondly, check the standard tightening of high-strength bolts, requiring that each node should be checked. Attention should be paid to the principle of symmetrical tightening and sectional tightening. Finally, check the gap of the top tightening surface, and require more than 80% of the area to be close to each other.Sampling anti sliding test and weld flaw detection test shall also be carried out on site.

(4) Control points of on-site welding: in design, site welding shall be reduced as much as possible, and weld quality control shall be strengthened if necessary. Firstly, it is not allowed to start operation in rainy and foggy weather, and the operation can only be started after sunshine for more than 1 hour. It is necessary to dry the welding rod with a heat blower. The welding rod shall be the same as that of the factory. It is the same batch number and used after drying. The welding of thick steel plate is better to be opened in the factory.Good groove, the first level weld is required to be carried out in the factory, after the completion of welding, it is required to carry out flaw detection for each weld.Control points of wall and roof enclosure structure: firstly, check whether the purlin and color plate meet the design requirements, pay attention to whether the thickness, material, manufacturer and surface coating meet the requirements, and check the quality certificate of all materials. Secondly, check whether the bite form of roof panel meets the design requirements. Then, during the installation process, the verticality, flatness, slab joint quality of each major surface shall be inspected.The form of hemming and flashing, waterproof quality and apparent quality.The surface color is subject to the determined sample.The manufacturer and technical parameters of other auxiliary materials shall be controlled according to the contract and design requirements.

(5) Control of fire retardant coating and anti-corrosion coating: focus on the control of material source, inspection report and on-site sampling test bond strength, and at the same time supervise the thickness and times of construction coating. The fire resistance limit is the main data to ensure the use function. The thickness of various components shall be selected on site by classification, and the acceptance of fire department shall be cooperated.

(6) Coordination of construction process: steel structure, enclosure structure and civil engineering structure are often completed by different units, sometimes there is no contract relationship between them. This requires a lot of coordination and schedule arrangement between the supervision (Management) unit and the owner, which will produce many contradictions, especially the coordination of construction period, site coordination, material storage, finished product protection, etc., which will affect the construction.It is unnecessary to increase the period, quality and cost, especially easy to cause safety accidents. Therefore, we should help and coordinate from the aspects of contract, management, organization and information. It is suggested that the owner should appoint the general contractor to coordinate on site. It is an ideal mode for the management and the owner to do a good job in planning and contract management.

(7) Strengthen safety supervision and management, implement the effective operation of safety responsibility system and safety management system, and control safety risks.

3、 Data sorting, filing and acceptance

After the completion of the project, it is necessary to urge the construction units to improve the technical data, sort them into volumes and prepare for acceptance.The supervisor shall organize all responsible subjects to carry out pre acceptance of the project. The supervisor shall carry out data acceptance inspection and acceptance report inspection, prepare quality assessment report and supervision work summary, inspect and transfer construction technology, management and quality assurance data, and assist the owner in project completion acceptance and data filing.