PSI - Issue 78

Laura Ragni et al. / Procedia Structural Integrity 78 (2026) 2094–2101

2096

central high-strength steel rod acting as a fuse. Two hydraulic jacks (300 mm stroke, 10 MN total force) and load cells apply and measure the pushing force. When the fuse breaks under tension, the building enters free vibration. However, due to the limited hydraulic capacity available on-site (maximum flow rate of 5 l/min), the pushing phase occurs at a low velocity, which affects the subsequent dynamic response. During testing, a comprehensive sensor system was installed, but this study focuses on data from horizontal displacement transducers at the isolation level. The list of tests are reported in Table 1. Further details on the building design, testing setup, and sensor layout are available in (Dall’Asta et al. 2022).

Push-and-release device

N

Columns

Vertical braces

Fig. 2. Floor plan of the CHIP building

Table 1. Test Sequence

Displacement 30 min after release/unloading start [mm]

Duration [min]

Max Force [kN]

Max displacement [mm]

Displacement at test start [mm]

Day Test Starting time

A1 10:55 S1 12:22 D1 13:47 S2 16:36 A2 10:11 D2 12:24 D3 13:36 A3 15:27 D4 15:56 S3 17:07

30

-

-

-

-

6

518

0.0

0.0 0.0

0.0

3rd July 2020

16 21 40

2729 3206

177.3 232.4

15.7 26.1

15.2

-

-

-

-

8

1756 3122

109.4 226.9

22.1 22.1

22.4 23.4

18 23

6th July 2020

-

-

-

-

9

1786 3834

121.8 284.6

22.1 22.6

22.9 36.2

25