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Due to the advantages of steel structure buildings, such as light weight, high strength, good seismic performance, the ability to arrange functional areas efficiently, short construction time, high recyclability value, and low overall cost, there has been an increasing use of such buildings in China in recent years. However, the construction of such projects presents three key characteristics in terms of safety production: first, all workers are involved in highly dangerous activities such as work at openings, edges, and heights throughout the entire process and around the clock; second, construction workers from various specialties as well as project management personnel operate in a highly dense environment with complex interactions between different tasks ； Third, all project components, construction equipment, materials, as well as various materials for safety protection facilities must be lifted and transported. These three characteristics pose numerous difficulties for the safety management of construction projects; therefore, the safety management of such projects is particularly important when compared to other construction and installation projects. From the perspective of safety management, **the standards and regulations do not cover this aspect in a comprehensive manner; the \"Safety Inspection Standards for Building Construction\" (JGJ59—99) include no inspection items related to this area. However, due to inadequate safety management and protective measures, construction accidents in steel structure projects are on the rise. The author draws on his experience in managing the steel structure construction of various projects, including the Shenzhen Diwang Building, Shenzhen SEG Plaza, Shenzhen China Resources Center, Shenzhen Dameisha Wish Tower, Shenzhen ZTE R&D Building, Shenzhen Tsinghua Information Port, Shenzhen Civic Center, Shenzhen Convention and Exhibition Center, Shenzhen TV Center, Shenzhen Wenjindu Passenger Transport Center, and the Huizhou LNG Power Plant. Let’s discuss the safety protection technical measures in the construction of steel structure projects, for everyone’s reference. I. Construction Facilities (1) Walkway Slabs When columns and beams have been installed but no profiled slabs for pouring the floor slab are yet in place, walkway slabs need to be laid on the steel beams. The laying method is usually as follows: steel pipes are arranged in a cross shape to form a grid, which is then fixed to the upper flange of the steel beam. The distance between adjacent steel pipes should not exceed 300 mm. A rebar mesh is laid on top, ensuring it is fully covered and compacted, to facilitate the construction of the next section of column and beam ； Furthermore, an overhanging safety net must be installed around the area, and temporary protective measures must be put in place at any openings. (II) Safety belts 1. To prevent falls from heights, operators must use safety belts when working at heights. Due to the large movement range during the construction of steel structure projects, ordinary safety belts are difficult to meet the construction requirements; safety belts equipped with speed-dependent automatic controllers should be used instead. There are many specifications for speed difference controllers (also known as speed difference devices, fall arrest devices, or fall buffering devices), with some having a moving radius of up to 30 meters. 2. When personnel climb the steel ladder, a fall arrest device is used to address the issue of lack of protection on the steel ladder. When using the self-locking device, care should be taken not to install it in the reverse direction ； When a person is climbing, the self-locking device should always be above the person. 3. After two or more columns are securely fixed, a steel wire rope (or thick hemp rope) must be used to facilitate the attachment of safety belts. 4. When installing the steel beams and supports, since a passage cannot be set up temporarily, when installing the steel beams connected to the steel columns, personnel should stand on the operating platform with their safety belts attached to the guardrails. When installing the steel beams connected to the main beam and the supports, a safety rope is attached to the main steel beam, and workers walk while wearing their safety belts attached to this rope. (III) Protection at openings: Guardrails 1.2 meters in height are constructed using scaffold pipes around elevator shafts, pipe shafts on the ground level, and openings with a side length of more than 1.5 meters; flame-retardant mesh screens are installed over these openings. A flame-retardant close-mesh vertical net is installed outside the railing. For openings, stairs, and edges on floors above the 2nd floor with side lengths greater than 1.5m, welded rebar guardrails that meet the requirements of the \"Technical Code for Safety in High-Height Work in Building Construction\" (JGJ80-91) shall be used; the specifications for these materials are: vertical bars of φ18mm, upper horizontal bars of φ16mm, and lower horizontal bars of φ14mm in terms of diameter. Flame-retardant close-mesh vertical nets are installed inside the railing. Holes and elevator shafts with a side length greater than 1.5m. Flame-retardant large flat nets are installed every two floors (with a flame-retardant fine-mesh safety net covering the flat net on the ground floor). The protective measures at the edge of the opening ensure the safety of the workers, while the net installed inside the opening prevents materials from falling from above and injuring those below. Hanging safety net: During platform construction, horizontal safety nets are installed across the steel beams of the second-level platform ； The turnover of safety nets must ensure that safety nets are fully installed in the lower area during the construction of the upper layer, in order to prevent falls from great heights. For work at cantilevered positions, steel pipe supports are erected during construction, along with double-layer safety nets to prevent falls from great heights. (IV) Hanging safety ropes on steel beams and columns: φ6 steel wires are hung from the steel beams at a height of 1.2 m. Scaffold pipes 1.2 m long are installed every 3 m to support these safety ropes. Alternatively, basket bolts can be used to tighten them, in order to prevent safety issues resulting from overly long safety ropes. When workers walk on steel beams, their safety belts must be attached to safety ropes. When lifting steel columns, in order to ensure that workers can remove the lifting wire ropes safely, an additional safety rope is attached at the hook; its height is determined based on the site conditions, and it is used to suspend safety belts. The temporary lifting ladder must be firmly and stably connected to the steel column, without any shaking, and its distance from the web should be no less than 150 mm. A schematic diagram of the safety rope is shown in Figure 1. http://www.hbsafety.cn/article/UploadPic/2008-4/2008499924932.gif (V) Setting up vertical passages to ensure the safety of construction workers when moving up and down. A steel ladder is suspended from the steel beam, and its ends must be securely fixed at both the top and bottom ； Steel ladders of different heights should be arranged offset from each other, with the number of ladders determined on-site. A rest platform should be provided at each section of the ladder. To ensure the safety of workers as they climb up and down, a safety rope is installed on the outside of the ladders. The workers wear special safety belts with self-locking devices; once they are in position, ordinary safety belts are used instead. A self-locking device is provided near each steel ladder for reuse. Schematics of the steel ladder are shown in Figures 2 and 3. http://www.hbsafety.cn/article/UploadPic/2008-4/2008499924403.gif http://www.hbsafety.cn/article/UploadPic/2008-4/2008499925731.gif (VI) Operation platform for the butt joint installation of steel columns. Steel columns are installed in segments. When carrying out docking and bolt tightening, to ensure the safe operation of workers, an operating platform is set up at a distance of 1.2 meters from the top of the first steel column. The number of platforms is determined based on the progress of on-site construction, to ensure smooth turnover and avoid any disruption to lifting operations. The settings of the installation platform create a favorable working environment for welders, ensuring their safe operation. This platform is easy to assemble and disassemble, and it is safe and reliable; it provides a secure working environment for processes such as the docking and installation of steel columns, alignment, treatment of weld surfaces, and ultrasonic testing. A schematic diagram of the operation platform is shown in Figure 4. http://www.hbsafety.cn/article/UploadPic/2008-4/2008499925579.gif (VII) Sling for welding operations (see figure below). The hanging basket is attached to the hooks located on the upper flange of the main beam. The welding operator can weld with confidence by attaching their safety belt to the steel beam or a safety rope. This hanging basket is easy to install and remove, safe and reliable, and has a wide range of applications. It provides a secure working environment for tasks such as the final tightening of high-strength bolts, the finishing of welds, and ultrasonic testing. http://www.hbsafety.cn/article/UploadPic/2008-4/2008499925749.gif (VIII) Erecting full-shade scaffolding and working platforms: For some projects, it is necessary to install large trusses; in cases where the span is very large or the height is extremely high, full-shade scaffolding and working platforms must be erected to facilitate the assembly of components and ensure the safety of workers, as in the case of the steel structure construction at Shenzhen Wenjindu Passenger Transport Center. (IX) Use of a spark trap: In welding and cutting operations, a spark trap can be used to prevent burns and fires caused by sparks generated during these processes. (10) Special clamps for lifting: Due to the irregular shape and sharp edges of steel structure components, there is a risk that the lifting steel cables may be damaged during the lifting process, leading to lifting accidents. Therefore, special clamps for lifting have been designed, and their use is mandatory during lifting operations. See Figure 5. http://www.hbsafety.cn/article/UploadPic/2008-4/2008499925925.gif (XI) Use of fall arrest devices: To ensure the safety of operators when ascending and descending steel columns, a fall arrest device must be installed on each column. When ascending or descending, the installer must attach their safety belt to the hook of the fall arrest device to prevent falls. The safety fall arrestor must be installed above the user, that is, it should be hung high and used at a lower level; horizontal hanging or hanging high and using it at a lower level is prohibited. (12) Use of warning signs and barriers (13) Steel cable hoists for installing roof panels, mainly used for installing roof tiles on roofs with large spans and high ceilings. See Figure 6. II. Protective Measures (1) On-site lightning protection measures: A lightning rod is installed at the highest point of the building, and it is connected to the grounding electrode through down conductors. The ground resistance must not be greater than 4Ω. (II) Safety protection measures for the installation (laying) of profiled steel sheets: The general sequence for laying profiled steel sheets is to first lay them out, then adjust them, and finally rivet them in place. Before starting the laying process, a horizontal safety net should be installed beneath the profiled steel sheets. Those responsible for laying and adjusting the sheets must wear safety belts or fall arrest devices, which must be fastened securely. Those who perform the riveting task should promptly rivet the adjusted sheets in place; it is essential that laying and riveting are carried out simultaneously, with no sheets left unriveted or skipped in the riveting process, in order to prevent the sheets from moving due to missing rivets. When laying profiled steel sheets, unauthorized personnel are prohibited from entering the construction area ； Personnel are prohibited from passing under the floor where profiled steel plates are being installed ； After the profiled steel sheets are installed, the openings should be sealed promptly, guardrails should be installed, and clear markings should be provided. (III) Measures for heat prevention and cooling, as well as construction during rainy and windy seasons: 1. To complete the construction of this project with high quality and in accordance with specifications, and to create the necessary conditions by making use of available time and adopting appropriate measures, construction protection measures for rainy and windy seasons have been formulated. 2. Keep track of meteorological data, maintain regular contact with the meteorological authorities, record weather forecasts on a regular basis, and provide timely updates so that the construction site can make appropriate arrangements and take preventive measures ； In particular, to prevent the impact of sudden adverse weather conditions on our construction work. Write the weather forecast on a board every day so that the workers are aware of it. 3. Before rainfall, take rain protection measures for the welded area and its heat-affected zone (set up rain shelters). 4. When the weather is severe during the rainy season, making it impossible to meet the technical requirements or to ensure safe construction, lifting operations should be halted. At this time, it is important to ensure the safety of the working area by implementing necessary temporary fastening measures (such as wind ropes and securing clips). 5. The hoisted steel structure should be reinforced before strong winds to ensure the stability of the steel components. 6. Welding operations must not be carried out in rainy weather. When continuous welding is required, appropriate rain protection measures should be put in place in the welding area (such as setting up protective canopies or covers). 7. During construction in the rainy season, safety protection measures must be appropriate and effective; water accumulation in tool rooms, operation platforms, suspension baskets, and welding shields should be cleared promptly. 8. During construction in the rainy season, it is necessary to meet the workers’ needs for slip prevention, rain protection, and water resistance (such as raincoats and non-slip shoes). Pay special attention to electrical safety. During rainfall, except in special circumstances or at specific work sites, high-altitude work should be halted, personnel working at heights should be evacuated to safe areas, and the power switches should be turned off. 9. The lifting equipment (crane) must be in its initial state; it is strictly prohibited to have the boom in a lifting position. 10. Drainage ditches shall be installed around the construction site and on one side of the crane routes to ensure smooth drainage and prevent water accumulation. 11. Steel components transported to the construction site must be protected from rain and moisture; they should be placed elevated, covered, or protected by sheds, with arrangements made according to the actual conditions. 12. Set up temporary rain shelters at the construction site; once the rain stops, ground work should be carried out immediately, and high-altitude work is strictly prohibited. High-altitude work should be carried out only after the rainwater on the steel beams and columns has dried. (IV) Fall prevention measures ① Measures to prevent objects from falling 1. Tools used in installation, such as torque wrenches, crowbars, angle grinders, etc., should be equipped with safety ropes to prevent them from falling. Bolts, washers, and other items used casually should be placed in a tool bag. 2. All objects that may fall during construction work must first be removed or secured. 3. When performing gas cutting or electric welding at heights, measures should be taken to prevent the cut metal, molten droplets, or sparks from falling and injuring people. 4. Ground personnel must not stay or pass directly below areas where work is being carried out at heights, nor must they stay or pass under the crane’s boom or the components being lifted. 5. During lifting and installation, it is necessary to first check whether the rigging, steel cables, and hooks are secure. Appropriate lifting points must be selected before lifting begins. If any safety hazards are detected, work must be stopped immediately and the relevant personnel informed. ②Measures to prevent personnel from falling: As much as possible, assemble the components on the ground before lifting them with a steel structure, in order to avoid or minimize work being carried out in a suspended state ； At the same time, safety protection facilities for temporary fixing, welding, high-strength bolt connections, and other processes that are carried out at heights must be prepared in advance, and these facilities should be lifted into place together with the components. In addition, safety measures during disassembly must also be considered and implemented. When installing steel beams, it is necessary to use the completed structure or an operating platform as a foothold; standing or walking on the steel beams during installation is strictly prohibited. If it is indeed necessary to walk on a firmly fixed beam surface, the temporary guardrail crossbars on one side can be made of steel cables ； When replaced with a handrail rope, the free sag of the rope should not exceed l/20, and it should be kept within 100 mm. (V) Fire and explosion prevention: 1. Fire extinguishers must be available, and they should be under the supervision of a designated person. 2. For welding and cutting at high altitudes, a spark trap must be installed; flame-retardant materials such as rock wool are used inside this trap to capture the molten droplets, preventing them from splashing back out of the spark trap. Sparks from electric and gas welding must never fall on oxygen cylinders or acetylene cylinders. 3. Oil-covered hands must not come into contact with oxygen cylinders, and care must be taken to prevent oil from cranes or other machinery from falling on them. 4. Oxygen and acetylene cylinders must be placed properly; an anti-backfire device must be used when using acetylene cylinders, and the safety operating procedures for electric and welding workers must be strictly followed. (VI) Safe electricity use at the site: Temporary electricity use shall be managed in accordance with the \"Technical Code for Safety of Temporary Electricity Use at Construction Sites\" (JGJ46—2005). 1. For electrical power used in on-site construction, the “three-level power distribution and two-level protection system” of one machine, one circuit breaker box, one switch, and one leakage protection device is implemented. Its electrical box is equipped with a door, a lock, a number, and the responsible person is indicated. 2. Mechanical equipment must implement protective measures of working grounding and repeated grounding. 3. The circuit breakers, leakage protection devices, and fuse ratings installed in the electrical box must be equal to the rated current of the equipment. Do not use fuses with currents that are too high or too low; it is strictly prohibited to use metal in place of fuses. 4. For the power supply at the construction site, the main electrical panels are arranged according to the overall layout of the construction area; during construction, connections are made separately for each area, and the wiring is protected by steel pipes. 5. Nighttime lighting facilities are temporarily arranged in sections and zones according to construction requirements. 6. Before leaving work, assign a dedicated person to inspect the construction site, turn off the power supply, and eliminate any potential safety hazards such as remaining sources of fire on site. 7. Install an no-load voltage reduction protection device on the secondary side of the welding machine. III. Reasonably arrange the sequence of construction processes to ensure the safety of concurrent construction activities; taking the sequence of laying profiled steel sheets as an example. In the construction of steel structure projects, each floor level corresponds to one layer of the structure. If the profiled steel sheets are installed from bottom to top as is usual, then flame-retardant mesh panels need to be installed and removed on the beam surfaces of all three floors. For the construction of each floor, it is first necessary to lay safety passages using a large number of 50 mm thick scaffolding planks; these tasks require significant amounts of labor and resources. Our approach during construction is to install flame-retardant large flat nets in the middle layer, while the installation sequence of profiled steel sheets is top layer first, then bottom layer, and finally the middle layer. The personnel responsible for installing profiled sheets on flat nets fasten their safety belts to the safety ropes to ensure the safety of the operators. Once the upper profiled steel plates are installed, they provide safety protection for the workers working in the middle and lower layers. The installation of profiled steel sheets starts from the center and radiates outward, eliminating the need for a separate process to lay safety passages. During the various processes such as welding the joints between the main beams and columns, treating the appearance of the welds, performing ultrasonic testing, and applying additional paint, a safety passage made up of two scaffold planks is laid only in the middle section of each axis. When working, the workers who lay profiled steel sheets should fasten their safety belts to safety ropes, steel ladders, or column clamps to prevent falls from heights and ensure safety.