Overall Calculation for Container Houses
Overall calculation for container houses covers two parts—structural calculation and building area calculation—each of which must follow the relevant codes and rules.
Structural Calculation
Structural calculation must strictly follow the Standard for Design of Steel Structures GB 50017 and the Load Code for the Design of Building Structures GB 50009. 1. Foundation load values: Roof dead load 0.3 kN/m², live load 0.5 kN/m²; floor dead load 0.5 kN/m², live load 2.0 kN/m² (civil residential standard); basic wind pressure 0.55 kN/m², basic snow pressure 0.4 kN/m²; steel grade Q235B, yield strength 235 MPa, factor of safety ≥1.5. 2. Bottom floor structure: Secondary beams are calculated as simply supported beams, with checks for flexural strength, shear strength, and deflection; main beams are verified under a continuous-beam model for overall load-bearing. Core criteria: maximum bending stress and shear stress in the floor main beams must not exceed the design strength of Q235 steel, and maximum floor deflection ≤ L/250. 3. Columns and side-wall structure: Corner columns must be checked for axial compressive strength, stability, and slenderness ratio; side-wall enclosure structures must be checked for flexural capacity and wind-pressure resistance of the wall frame and wall panels. Container houses with windows or doors must have reinforcing frames and vertical stiffeners added at openings, with local reinforcement verification. 4. Roof structure: Roof purlins, main beams, and roof panels must be analyzed, with emphasis on flexural capacity under snow load and stability under wind uplift, while strictly controlling roof deflection to keep drainage slopes stable. 5. Overall stability and foundation connections: Overturning and sliding resistance must be verified, meeting stability requirements through ballast, anchor bolts, or foundation anchorage; foundation connections must be checked for uplift and shear capacity of the anchor bolts.
Building Area Calculation
Per the Ministry of Construction's Rules for Calculating Building Area, calculations must comprehensively account for structural characteristics, use function, and degree of modification. 1. Standard container area: Theoretical building area of a 20-ft standard container is 14.77 m²; 40-ft standard and high-cube containers are both 29.73 m², measured by the horizontal projected area of the outer wall perimeter. 2. Story-height effect: Full area is counted when story height exceeds 2.2 m; half area when under 2.2 m; multi-story containers must be calculated floor by floor. 3. Special structural parts: Cantilevered portions with column support are calculated by the area outside the columns; free-standing columns by half the projected area of the canopy; entrances with permanent canopies by the canopy projected area, and without canopies not counted; modified openings are still calculated by the original outer contour; roof terraces with enclosure structures by outer perimeter area, and without enclosure by half the projected area.
