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This post was last edited by altpage on 2016-8-15 at 14:21. As we all know, steel structures are **preferred green building materials; they represent the most popular and common type of structure in current construction projects, and they enjoy wide recognition among the public as well. With the rapid economic development of our country and the needs of urban construction, steel structure pedestrian overpasses have been widely used in recent years. http://www.gzganggou.com/uploadfile/image/20160812/20160812110878897889_ZYCH.jpg Steel structure overpasses are generally recommended to be installed in busy areas where there is a high volume of pedestrians and vehicles. To ensure the safety of pedestrians and facilitate traffic, certain safety measures must be taken during the installation of such overpasses. Construction technical features of steel structure overpasses: 1. By setting temporary positioning piles and elevation markers at the lower end frames where the pedestrian overpass meets the building structures, it is possible to effectively position the bridge structure and control its elevation, thereby ensuring safety and speed while also guaranteeing the construction quality of the steel structure overpass. 2. When welding the bridge deck panels, submerged arc welding technology should be used in place of the traditional arc welding method; this improves both the welding speed and quality. It also reduces the generation of harmful gases and dust during construction, thereby contributing to environmental protection. 3. During installation, mechanical lifting is primarily used; for steel structure overpasses, segmental installation is usually adopted, and the installation of such overpasses involves aerial docking, which is quite challenging. A safe operating platform is required, and since construction work involving a large number of temporary supports is often constrained by various conditions, it is essential to grasp the key points of installation and prepare for rescue operations. 4. During the lifting process, a gap of 50–100 mm should be maintained between the end plates of the bridge deck and its ends; the alignment of the bridge deck is achieved by using rollers installed at the lower end of the bridge deck. It is essential to avoid any collisions between the bridge decks during lifting, as this could affect the progress of the lifting operations. 5. After the bridge deck sections are joined together, cover welding, root welding, and tack welding should be carried out immediately. Once these steps are completed, the structure can be left in place for at most one night; if the environmental humidity is high, the time it can remain there needs to be adjusted, otherwise rusting will occur. If water-induced rust is detected, it must be dried out right away, and removed completely before welding begins. 6. When setting up a welding workshop at the construction site, wind protection measures such as windshields should be installed; welding work must not be carried out in rainy weather. When welding inside the bridge structure, certain wind protection measures should be taken to ensure construction safety. The above are several safety precautions summarized for the construction of steel structure overpasses. Before welding, it is necessary to check whether the butt joints, gaps, and height differences of the plate surfaces meet the requirements specified in the design and relevant standards; at the same time, it is important to verify that the site conditions meet the environmental requirements for welding work. When the wind force is ≥ level 5 and the humidity is >85%, it is possible to set up windproof shelters. The construction of steel structure overpasses poses a risk to human safety; therefore, the contractors must exercise strict control over every detail of the construction process.