General Information
Figure 1 shows the construction site of a commercial building extension.
I-Beam
Figure 2 shows a schematic cross-section of the structure.
The new steel structure consists mainly of columns, beams, purlins, and metal roofing sheets. The continuous I-beam has 5 supports (A to E). The overhang m ≅ 2.5 m, the span s ≅ 12 m, and the span n ≅ 10 m. Figure 3 shows the span s region.
The I-beam height h ≅ 15 cm. Figure 4 shows the span s region viewed from below.
The purlin span p ≅ 5 m, while the purlin span q ≅ 9 m. The finished building extension includes a suspended ceiling with gypsum boards, as shown in figure 5.
I-Beam to RC Structure Connection
The I-beam between supports A and B is shown in figure 6, while the connection to support A is shown in figure 7.
The connection consists of an end-plate and four anchor bolts. The end-plate has two empty holes and a broken corner. The anchor bolt layout is asymmetric, and two adjoin the base plate.
What are the main problems?
Purlins
Figure 8 shows a roof sector viewed from below.
A purlin consists of a built-up section made of two side-by-side placed rectangular hollow profiles that are welded together as shown in figure 9.
What are some possible reasons for using the above shown purlin type?
Metal Roofing Sheets
Figure 10 shows a roof sector viewed from below.
There is a hole in the metal roofing sheet.
What are the main consequences?
External Columns
Figure 11 shows a front view of two external columns (E).
Enlarged view 1 is shown in figure 12.
The H-shaped column has a circular hole in the top-end web region.
Figure 13 shows an RC slab connection.
The connection consists of a base plate and four anchor bolts. The column center is away from the base plate center, causing a column sector to protrude out of the base plate.