General Information

Figure 1 shows an attached carport.

Attached carport.
Attached carport with a timber roof structure and zinc roofing sheets

The structure consists mainly of three columns, longitudinal and transverse beams, purlins, and corrugated zinc roofing sheets. The columns are made of reinforced concrete, the longitudinal beams and the purlins are made of timber (rectangular sections), and the transverse beams are made of peeled logs. The span s ≅ 4.5 m, and the columns' spacing a ≅ 2.5 m.

Structural Connections

Figure 2 shows the roof structure.

Roof structure (attached carport).
Building attached carport with a timber roof structure and zinc roofing sheets

The zinc sheets are nailed (umbrella head nails) over the purlins, the purlins are nailed over the transverse beams, and the transverse beams are notched at the ends and nailed over the longitudinal beams; the connection to the building consists of three anchor bolts (1 to 3) with a spacing of approximately a (columns' spacing). Figure 3 shows anchor bolt 3 region.

Longitudinal beam to building connection (anchor bolt 3).
Connection between carport and building

The longitudinal beam and the building are in direct contact (no gap) over the entire building length. Figure 4 shows the connection between the longitudinal beam and the column.

Longitudinal beam to column connection.
Connection between timber beam and RC column of an attached carport

The longitudinal beam is placed over the column and fastened with its four (protruding) rebars, which are bent over the longitudinal beam. A schematic lateral view of longitudinal beams 1 and 2 is shown in figure 5.

Longitudinal beams.
Lateral view of two overhanging timber beams of an attached carport

Both beams have the same cross-section, mechanical properties, and distances between the supports; the red arrows (F1 and F2) represent vertical forces placed at the free ends of the overhangs (o).

  • Suppose that F1 and F2 are failure forces. Is F1 approximately F2?
    Is the failure mode of both beams the same?
    What are other possible structural connections? How do those connections affect the beams' behavior?
  • Materials

    Figure 6 shows a schematic three-dimensional view of the carport.

    Attached carport.
    Three-dimensional drawing of an attached carport

    Consider the reinforced concrete columns, the timber roof structure, and the zinc roofing sheets.

  • How do those materials interact with the atmosphere?