Designing Steel Structures

Steel structure buildings are increasingly popular in the construction market due to their rapid construction speed, factory-made components, high level of industrialization, good appearance after installation, long service life of steel materials, durability, and recyclability of materials. As the popularity of steel structure workshops continues to grow, the issue of construction cost has also attracted more and more attentions. How to ensure the durability of the steel frame structure while controlling the cost has become a key concern for many steel structure suppliers. Below are some key factors affecting the cost of steel structure workshops and how to control costs through reasonable design and construction management.   Raw Material Factors: Steel and sheet steel materials are the main components of the steel prefabricated building's framework, accounting for about 70% to 80% of the total cost. Fluctuations in steel market prices due to supply and demand directly affect the cost of the steel prefabricated buildings. The cost of light steel structures varies with different materials and specifications of the sections, as well as the thickness and material of the cladding plates. Therefore, raw materials are a key factor affecting the cost of light weight steel structure garages.   Design Factors: Reasonable design is the key factor for saving raw materials and controlling budget. Different design drawings will affect the amount of raw materials used, thereby affecting the total cost. Experienced designers, by considering the location and environment of the steel structure workshop, as well as the specific needs of the client, can provide cost-effective architectural design drawings. Similarly, in environments with few earthquakes or low wind forces, excessive stacking of materials or over-emphasizing the seismic capacity of the steel framed structure often leads to a sharp increase in construction costs. Therefore, choosing a designer with industry experience is crucial during the design phase of the steel structure buildings.   Foundation Design: The cost of the foundation is closely related to geological conditions. The construction of the foundation is an important factor in the stability of the steel structure factory building, and its construction period accounts for about 25% of the total construction period, with the cost of foundation construction accounting for 15% of the total cost of the steel structure project. In the design phase, it is necessary to fully consider the geological report, choose the appropriate foundation type, and reasonably control the size and depth of the foundation to effectively control the total cost. For example, in areas with soft soil, the foundation depth is deeper, and the cost is often higher. In areas with hard soil, the foundation for the steel structure is shallower, and stability can be maintained without the need for a deep foundation.   Column Grid Design: The column grid layout determines the span, spacing, and number of columns in the steel structure building. Under the premise of meeting the needs and process requirements, it is preferable to choose a small-span portal steel frame. Although this small-span design increases the number of columns, it reduces the use of materials such as the steel structure roof and steel beams, achieving better economic benefits. The economic column spacing is usually 6 to 9 meters, and exceeding this range will increase the steel consumption and thus the cost. Of course, the number and layout of columns should not only meet economic requirements but also consider the needs of the steel structure workshop. In some steel structure industrial building that need to be used as warehouses, an overly dense number of columns increases the risk when vehicles enter and exit or when moving items.   Beam Design: The rectangular section beam is a common bending member, often used in design, but has a low material utilization rate. One reason is that the material stress near the neutral axis is low; the other is that the bending moment of the beam changes along the length. Because most sections of the equal section beam have low stress, the material is not well utilized, and the material utilization rate can only be improved when the beam is subjected to axial force. Therefore, during the design, planar trusses can be used to replace rectangular beams. Planar trusses are equivalent to hollowed beams, removing excess material from the beam, which is both economical and reduces self-weight. It can also develop into a spatial grid, greatly improving the material utilization rate.   Construction and Installation Factors: The length of the construction period also affects the cost. A long construction period often leads to an overspend in the overall budget of the prefabricated steel structure workshop. How to save the installation and construction period to reasonably control costs is particularly important. Among them, the proficiency of the installation team is the key to determining the construction period. Experienced installation teams, through reasonable time arrangements for the assembly of various components and the reasonable use of engineering machinery and equipment during installation, can improve installation efficiency without increasing a large amount of installation costs. Building a steel structure workshop is a complex system project, involving many aspects such as the construction period, policy changes, and project scale, all of which can affect the cost.