General Information

Figure 1 shows an attached carport.

The structure consists mainly of columns, trusses, suspension rods, carport to building connection units, purlins, and asbestos roofing sheets.

Structural Concept

Figure 2 shows the carport.

The length l ≅ 18 m, and the width w ≅ 5.5 m. External truss D is connected to a front and a back column (5 and 4), while the remaining three trusses are each connected to a back column (1 to 3). The back columns are made of I-sections, while the front column is made of a circular hollow section. The trusses are tapered toward the back columns, and the end units of the internal trusses have two more members (marked by the blue background). Figure 3 shows a lateral view of the carport.

Each truss is connected to a suspension rod made of a rectangular hollow section; the connection is located away from a truss node. Each back column connects a truss, a suspension rod, and a carport to building connection unit (marked by the blue dashed lines). The latter consists of three members: two horizontals and a diagonal; the horizontals are connected to the RC structure of the building. Figure 4 shows a bottom view of the roof.

Roof cross-braces made of steel wire ropes are installed between the trusses; they are connected to the bottom chords by single-hole welded plates, and the wire rope termination consists of a single U-bolt clamp. Figure 5 shows a cross-brace to bottom chord connection, while figure 6 shows a schematic three-dimensional view of the carport.

Carport to Building Connections Failures

Figure 7 shows the carport.

The horizontal members of the carport to building connection units of columns 2, 3, and 4 failed (marked by the yellow arrows). Figure 8 shows a lateral view of the carport to building connection unit of column 4.

Detached horizontal members and vertical cracks on the RC column of the building are noticeable.