The two 3:4 scaled prototype frames were irregular in elevation due to the excessive stiffness variation (greater than 30%) between two adjacent floors. In fact, interstory height was 4.8 m (16 ft) at the first floor and 2.4 m (8 ft) for the top two stories, while a 500 × 500 mm (20 × 20 in.) column cross section was kept constant along the height. The floor span was 3.45 m (11.3 ft), while the frame spacing was set as 5.2 m (17 ft). Beam cross sections were 500 × 350 mm (20 × 14 in.), 500 × 450 mm (20 × 18 in.), and 500 × 450 mm at the first, second, and third floors, respectively. Figure 4 shows the two specimens tested and a schematic of their 3-D reference building, while Table 1 summarizes the values of dead and live loads used in design. Their computation was performed by assuming the slabs to be unidirectional because the most common flooring system in Italian building practice consists of prestressed double-tee joist or hollow-core slabs29,30 with or without cast-in-place concrete topping. These single-span systems are usually simply supported on inverted-tee framing beams. Continuity in terms of horizontal seismic load transfer is ensured by cast-in-place concrete topping or shear keys. Two-dimensional representations of two specimens were extracted from a reference 3-D structure; therefore, the slabs were not provided, while their weights were considered and reproduced in the tests.
The two 3:4 scaled prototype frames were irregular in elevation due to the excessive stiffness variation (greater than 30%) between two adjacent floors. In fact, interstory height was 4.8 m (16 ft) at the first floor and 2.4 m (8 ft) for the top two stories, while a 500 × 500 mm (20 × 20 in.) column cross section was kept constant along the height. The floor span was 3.45 m (11.3 ft), while the frame spacing was set as 5.2 m (17 ft). Beam cross sections were 500 × 350 mm (20 × 14 in.), 500 × 450 mm (20 × 18 in.), and 500 × 450 mm at the first, second, and third floors, respectively. Figure 4 shows the two specimens tested and a schematic of their 3-D reference building, while Table 1 summarizes the values of dead and live loads used in design. Their computation was performed by assuming the slabs to be unidirectional because the most common flooring system in Italian building practice consists of prestressed double-tee joist or hollow-core slabs29,30 with or without cast-in-place concrete topping. These single-span systems are usually simply supported on inverted-tee framing beams. Continuity in terms of horizontal seismic load transfer is ensured by cast-in-place concrete topping or shear keys. Two-dimensional representations of two specimens were extracted from a reference 3-D structure; therefore, the slabs were not provided, while their weights were considered and reproduced in the tests.
การแปล กรุณารอสักครู่..