Earthquake in Taiwan: dozens under the rubble and over 1000 injured. An Italian maxisphere saved the Taipei tower


By John

The largest earthquake to hit Taiwan in 25 years has so far killed at least nine people and injured more than a thousand.. But there are dozens missing and trapped under the rubble or in coal mines, like the 70 workers caught in the bowels of the earth by the violent earthquake of magnitude 7.4, according to the American USGS, or 7.2 according to the findings of the Taipei authorities.

In 1999, the 7.6 quake killed about 2,400 people and damaged or destroyed 50,000 buildings. The county of Hualien, the one on the east coast which tradition has it as 'the first to be caressed by the rising sun', was the epicenter of the earthquake which it shook the entire island with great intensity around 8 in the morning (2 am in Italy) and surprised those who were going to work and school; as well as triggering a tsunami warning which returned only a few hours later.

Taiwanese television stations broadcast images of tilted buildings and twisted into precarious angles near the epicenter, which was spotted just off the coast at a depth of about 15 km. First responders used simple ladders to help stranded people get out of windows, while large landslides caused at least four victims occurred in the inland mountainous parts.

In Taipei the iconic '101' skyscraper swayed dangerously both for the first shock and for subsequent aftershocks, while the subway and high-speed trains were blocked for safety inspections. The national fire agency said efforts were underway to evacuate dozens of people trapped in tunnels near the city of Hualien, including two Germans, who were later freed. While you are lost contact with 50 tourists on board 4 minibuses heading to a hotel in Taroko national park, in view of the long holiday weekend. The Taiwan Center for Science and Technology also reported that around 100 people and vehicles were stranded in the Jinwen and Daqinqshui tunnels under the Hualien Mountains. “At the moment the most important thing, the highest priority, is to save people,” said President-elect William Lai, speaking outside one of the most damaged buildings in the city of Hualien, whose county has remained cut off from the rest of the island between the collapse of bridges, landslides and the breakdown of the road network. The Taiwanese Air Force itself had to deal with the earthquake: 6 F-16 fighter jets were damaged slightly in one of the main bases of the city from which they often take off to repel incursions by Chinese planes, but the forecast is that they “will return to service very soon”.

State media in Beijing reported that the earthquake was felt as far away as Shanghai, but especially in the province of Fujian, which is located opposite Taiwan. The aftershocks could continue for four days, experts have warned: more than 50 have been recorded today, of which at least twenty above magnitude 4. «The epicenter was close to the surface and the earthquake was felt throughout Taiwan and offshore islands,” said Wu Chien-fu, director of the Seismological Center of the Central Weather Administration in Taipei. Most electricity has been restoredthe utility Taipower reported in the evening, while the island's two nuclear power plants are considered safe.

Foxconn, the largest iPhone assembler, halted some production lines but added that normal operations had gradually resumed. Taiwan Semiconductor Manufacturing Co (TSMC), a world leader in microchips and an important supplier to Apple and Nvidia, reported that “to ensure the safety of personnel, some plants have been evacuated.” Production was suspended for the rest of the day and only on Thursday will the picture on the possible impact be clearer, including on a global scale. Its shares closed on the Taipei Stock Exchange down 1.3% while the Taiex index (-0.63%) essentially ignored the impact of the earthquake.

An Italian maxisphere saved the Taipei tower

The record-breaking skyscraper, Taipei 101, was saved from the earthquake thanks to a maxisphere placed between the 87th and 92nd floors of the building, fruit of the work of a Selvazzano company (Padua), Fip Mec, and which was tested by Renato Vitaliani, former professor of civil, construction and environmental engineering at the University of Padua, now retired. AND' a sort of maxi pendulum, Vitaliani tells ANSA, which balances the shocks, a sort of harmonic absorber that prevented the skyscraper, the eleventh largest in the world, from collapsing to the ground. Vitaliani tested the work – he himself recalls – about ten years ago, 'certifying' the functioning of the enormous steel sphere of 660 tonscapable of balancing seismic shocks and strong gusts of wind, which was placed on the summit of Taipei 101, 508 meters above sea level in Taiwan.

The Tuned Mass Damper installed inside the skyscraper is the largest in the world, a sort of harmonic absorber that prevents structural failures in the event of high-level tremors. «Fip of Padua has been producing anti-seismic devices which since 1974 represent the most advanced techniques for the protection of bridges and buildings – he says -. For the Taipei 101 he created the viscous sphere dissipator, and I tested it.” The building tilted but still resisted the incredible shock wave of the earthquake. «In my opinion, from a first analysis – explains Vitaliani – it tilted due to the liquefaction of the ground» . After the first techniques used in the 1950s in Japan «by compacting the ground and then placing gravel, so that the building 'slipped' over it, now there are insulators – underlines the professor from Padua – which are more performing and are placed under the pillars and I can be in neoprene or the double pendulum that FIP ​​first experimented with, using it for the L'Aquila earthquake.” A pendulum, therefore, which as in Taipei acts «in phase opposition to the oscillations induced by the tower and therefore significantly reduces them. Around there are energy dissipators, damping systems – adds Vitaliani – which block the pendulum when the earthquake ends to avoid damage to the structure”. In other words, the sphere with a diameter of 5.5 meters made up of 41 discs and supported by eight hydraulic pumps counterbalances the oscillationsas already happened during its construction, when it withstood a 6.8 magnitude earthquake.