Matters to Note During Calculation

 

　　1. Regarding the Format of Engineering Quantity Calculation

 

　　1.1 The unit of weight for steel structures is kg, the unit of area is m2, and the unit of length is m. Calculation results are all rounded to one decimal place.

 

　　1.2 When calculating the weight of components, the parts of the component can be numbered from bottom to top and from left to right, and calculated in this order.

 

　　1.3 Calculation Formula Format:

 

　　1.3.1 Plate: Specification × Length × Width × Quantity

 

　　For example,-6×500×300×5 indicates that the plate thickness δ=6mm, the plate length is 500mm, the width is 300mm, and the quantity is 5 pieces.

 

　　The weight calculation formula is: 6×0.5×0.3×7.85×5=35.3kg

 

　　1.3.2 Profile: Specification, Length × Quantity × Specific Gravity

 

　　For example, L50×5, L=3500mm×5×3.77 indicates an equal-angle steel with a leg width of 50mm, a length of 3500mm, a quantity of 5 pieces, and a specific gravity of 3.77kg/m.

 

　　The weight calculation formula is: 3.5×5×3.77=66.0kg

 

　　2. Several Points to Note When Calculating Dimensions

 

　　2.1 Note the elevation values of indoor and outdoor steel column base plates, whether they are ±0.00 or other elevation values. When using elevation values to calculate length (or height), pay special attention and do not calculate them all as ±0.00.

 

　　2.2 For the calculation of the height (or length) of stiffening plates, purlin braces, parapet wall capping brackets corresponding to variable H-section members (beams, columns), the average height of the H-section beams and columns can be used as the base number for calculation.

 

　　2.3 The length of the roof purlins is calculated as the full length, excluding the gaps between the purlins. In addition, pay attention to adding the length of the purlins occupied by the roof beams at the gable ends. For example, the axis line represents the center line of the roof beam, then: Purlin length = Axis length + Roof beam width.

 

　　2.4 For the calculation of wall purlins, pay attention to whether the door posts and door beams are double purlins, and whether there are double purlins in other parts.

 

　　2.5 The length of the tie rod is calculated by adding 50mm to each end according to the corresponding purlin spacing, and the length of each tie rod is increased by 100mm.

 

　　2.6 Regarding the Calculation of Finishing Flashing Parts

 

　　2.6.1 Calculation Scope: Ridge cover plates, flashing plates at the interface of gutters and roof panels and parapet walls, flashing plates at the interface of gable walls and roof panels, top flashing plates on parapet walls, finishing plates at wall corners, finishing plates around doors and windows, flashing plates at the interface of wall panels and brick walls, flashing plates at the interface of walls and awnings, finishing plates around awnings. If it is a double-layer plate, the finishing parts at the interfaces of the inner roof plate and inner wall plate are calculated separately.

 

　　2.6.2 Regarding the width of finishing flashing plates: Under normal circumstances, the unfolded width of finishing flashing parts can be calculated as 300~400mm, and the unfolded width of parapet wall capping and ridge cover plates can be calculated as 500~700mm. During actual calculation, it can be calculated according to the corresponding connection details of the design.

 

　　2.7 For the web plates of variable-section beams and columns, the weight is calculated based on the net weight during bidding, subcontracting settlement, and cost calculation, and is calculated based on the outer rectangle when settling accounts with the client. All connection plates are calculated based on the outer rectangle.

 

　　3. Parts That Cannot Be Calculated Repeatedly

 

　　3.1 High-strength bolts: The connection between columns and beams, and the connection between crane beams are shared by two components and cannot be calculated once for one component.

 

　　3.2 Roof supports, tie rods, inter-column supports: Some construction drawings show the layout of part of the roof supports on the inter-column support drawings, and they have already been calculated when calculating the roof supports, so they should not be calculated again. In this case, the drawings of the roof supports and wall supports should be compared.

 

　　4. Other Matters to Note

 

　　4.1 When calculating the specific gravity of profiles, especially H-shaped steel and steel pipes, do not forget to subtract the thickness that should be subtracted. For example, when calculating the specific gravity of steel pipes, do not calculate them as round steel, but subtract the area occupied by the inner diameter.

 

　　4.2 When checking the specific gravity of materials in hardware manuals or other materials, be sure to check carefully and do not check wrong.

 

　　4.3 When calculating the specific gravity of C-shaped purlins, it can be calculated according to the unfolded area.

 

　　4.4 Do not omit the calculation of the frames of hollow sun panels, aluminum-plastic panels, and other decorative materials.

 

　　4.5 All calculation processes require carefulness and accuracy, and must not be careless. Generally, two calculations should be performed for verification. Remember the saying, "A slight error can lead to a big mistake." Low calculation accuracy or errors will have very serious consequences. In addition, we must be willing to ask questions, be humble and eager to learn; often go deep into the engineering front line, understand and familiarize ourselves with various construction processes and procedures, deepen our impression, and lay the foundation for better doing pre-settlement work.