I. Preparatory Work Before Budgeting

 

　　Before budgeting for steel structures, beginners should have some necessary knowledge. First, understand the steel structure construction process, specifically how materials are received, cut, and installed for each step. This helps avoid errors in calculating engineering quantities and identifies areas with higher material loss. Additionally, study steel structure construction standards, such as the arrangement, requirements, and quantity of column base plates. Learn about non-destructive testing, such as the requirements for welding seams of H-beams (understanding the difference between flanges and webs, and the required percentage of testing for each), and familiarize yourself with the quantity standards. Understand the various items included in the steel structure fabrication and installation quantity standards, and which items apply to a specific engineering quantity, clearly marking different items in the calculation draft for easy review.

 

　　After reviewing the quantity standards and understanding their items, study the engineering quantity calculation rules. Learn what to pay attention to when calculating each item, such as the unit of measurement (m or m2). For example, steel structure testing is measured in meters (m) for weld length, and metal plate surface flaw detection is measured in square meters (m2). Especially remember what a combined platform is, because this item has higher costs. A combined platform is a platform connecting two or more pieces of equipment, facilitating maintenance; calculations should include the weight of ladders, railings, and handrails. For example, when calculating platforms on a frame, all components except columns and main beams can be considered as a combined platform. Carefully review steel structure construction technical measures, such as how the frame is lifted and installed in sections or segments, and the reinforcement methods used to calculate the engineering quantity of steel structure lifting and reinforcement. The measures can also help determine the specifications and quantity of lifting lugs required, and the type and size of platform used for prefabrication for calculation.

 

　　II. How to Extract Engineering Quantities from Drawings and Points to Note

 

　　Now, let's examine the drawings. Don't be intimidated by the volume. Steel structure drawings are relatively simple, and understanding them is straightforward with careful review. However, before starting the extraction, check if all drawings are complete, identify the relevant section (e.g., walkways, frames, ladders), and review the technical specifications and markings. Review the drawings thoroughly, and if there are areas you don't understand, carefully examine them in context. Before extracting quantities, review the specified node diagrams. Understand terms such as column major and minor axes, and how beams connect to beams and columns, and study the composite node diagram. Clarify specific terms, such as cantilever beams: when one end of the beam is steel-connected to a column or beam, and the other end is hinged to a beam, the beam model/F-L indicates left-end steel connection, and the beam model/F-R indicates right-end steel connection. The draft must be clear and easy to understand to facilitate later review, clearly marking different items, specifying which quantities are for the frame, and which are for the combined platform. Clearly distinguish between steel grades, such as Q235B and Q345B.

 

　　Next, extract quantities from the drawings in order, but always consider the context, avoiding duplication or omission. Beams shown in fixed elevation plans should not be recalculated in elevation drawings because they are more intuitive in the plan. Recalculation in elevation drawings would lead to duplication. If elevation drawings show beams at elevations not explicitly shown in plan drawings (e.g., an elevation drawing shows a beam at 12m when plans only show 10m, 20m, and 30m), those beams should be calculated in the elevation drawings, but note whether small platforms exist at that elevation; if so, calculations should be done in their respective platform plans to avoid duplication. Cantilever beam braces not calculated in plan drawings should be calculated in elevation drawings.

 

　　When calculating from plans, avoid calculating all ladders for a single elevation at once, as this is prone to duplication and inefficient. For example, if you calculate ladders at 10m elevation, then calculate them again at 20m, the result may be duplicated calculations (same ladder). Instead, calculate ladders after other quantities are completed, considering all elevations together. This approach reduces the risk of duplication or omission, allows you to count the number of ladders, and calculate one ladder's quantity and multiply by the total number, improving efficiency by avoiding repeated searches for detailed ladder drawings.

 

　　When calculating column lengths, note the base elevation and deduct the base and top plate thicknesses. Base plate thickness can be obtained from the drawings, but top plate thickness varies depending on the column and is obtained from the node diagram. Node plate calculation is challenging; carefully study the node diagram before calculation. If the node plate is not a regular rectangle, calculate the area as a rectangle using the longest and widest sides. Distinguish between steel-connected and hinged beams, as the supporting beams and node plates differ. When calculating composite node plates, avoid duplication; calculate column tops and mid-sections separately. Note that node diagrams differ for beams with heights greater than or less than 50, and calculations should be performed accordingly.

 

　　When calculating special quantities, also calculate their fabrication and installation quantities. For example, when calculating a sector platform, determine the specifications and number of angle steel rings needed, to avoid later searches. After completing quantity calculations, determine the number of H-beams requiring testing according to standards, and calculate the weight of steel structure lifting and reinforcement according to technical measures.

 

　　III. How to Apply Quantity Standards to Prepare a Budget and Points to Note

 

　　Electronic document entry will be needed later for easier searching and calculation. After entry, the calculated quantities should be summarized according to different quota items, and a main material table should be compiled. When compiling the main material table, the previously calculated quantities should be multiplied by the loss rate. The loss rates vary in different places. Remember that there is no loss for steel partitions. Carefully study the quotas, apply the calculated quantities to the budget, and remember that the budget quantity is the net quantity calculated. When calculating the anti-corrosion paint brushing, remember that steel partitions are not painted. Generally, only the fire-prevention part of H-shaped steel is brushed with primer, not topcoat. All other parts are brushed with both primer and topcoat, but the specifics should be based on the specific drawing requirements. After applying the quotas and summarizing all items, anti-corrosion height calculation should be performed. Generally, the height exceeding part is 15% of the anti-corrosion part multiplied by the man-machine. When calculating the scaffolding height fee, it is calculated at 8% of the labor cost, and the direct quota fee is obtained before charging. Then prepare the basis for compilation and the charging table. If the client in your region requires software, you can learn the software and transfer the Excel format budget to the software version, or directly transfer the budget to the software version. The software is very convenient for calculating the height fee and scaffolding erection and dismantling fee.