Hanoi has a stronger earthquake than HCMC

This morning's earthquake caused Ho Chi Minh City to "shudder" again to raise concerns about Hanoi's stamina because it once buckled the 6.5 magnitude earthquake, not inferior. much compared to the intensity of the earthquake that destroyed Haiti (7 richter scale).

Influenced by the magnitude 4.7 earthquake, occurring in Binh Thuan province on the morning of June 23, many buildings in Ho Chi Minh City shook at a level that made people living in the upper floors feel clearly . Many people are surprised and worried, running down the road to ensure safety.

In 2005 and 2007, the city was also shocked by the magnitude 4-5 earthquakes that occurred on this fault zone.

Dr. Le Huy Minh, Director of the Earthquake Alert and Tsunami Warning Center, Institute of Geophysics, said the earthquake this morning made HCM "shudder" just a normal geological development, occurs in the Binh Thuan - Vung Tau fault system, and will not affect Hanoi.

Level 8 earthquakes may occur

However, according to experts, the event once again raised concerns about Hanoi's stamina. "The capital of Hanoi is located in the region with the possibility of a level 7 or 8 earthquake. Historically, earthquakes on the upper level have occurred in Hanoi in the years 1277, 1278 and 1285, causing a shocking The movement is very strong, causing soil to crack, erode, many damaged works , "said Dr. Le Huy Minh.

As noted, the largest earthquake level in Hanoi is level 8, equivalent to 6.5 richter. Although it is only considered to be an average earthquake by the world standard, but this figure is not inferior to the intensity of the earthquake that destroyed Haiti (7 richter scale) and this makes many people startle.

The scene after the earthquake destroyed Haiti.

What if the capital of Hanoi would be if a strong earthquake of level 8 broke out with the epicenter in the inner city of the city (which is quite possible in theory)?

'Making an accurate scenario about earthquake consequences in Hanoi is very difficult. Only sure, the level of devastation of such an earthquake will be small. According to the calculation principle, none of the works cannot be damaged by earthquakes. The purpose of the calculation is to make the damage to the lowest level, human damage to a minimum, ' Professor Tran Chu said, adding that the black spot about earthquake safety in Hanoi The present time is the dormitories that have been damaged and degraded. Across the city there are still dozens of buildings listed as 'dangerous apartments'. Under the impact of strong shocks, the collapse of these buildings is not hard to imagine.

'Someone said that those old buildings have existed for ten years, what's wrong ?. That subjective attitude is unacceptable. Although the probability of an earthquake is very low, we must respect the objective law of nature so as not to be startled when a horrifying event like that has happened in the past many years, 'said Professor Tran Chuong. share.

Lo for Kim Lien, Thanh Cong and Giang Vo collective quarters .

Referring to earthquake resistance (seismic resistance) of construction works in Hanoi, Prof. Dr. Tran Dang, Head of Quality Department of Vietnam Construction Association, said: 'Previously, construction works The construction must comply with the standards for calculating seismic resistance of the Soviet Union. Since 2006, Vietnam has a new standard of TCVN 375: 2006 standards for earthquake-resistant construction.

High-rise buildings are those most affected by earthquakes.Photo: thegioicanho.com

Until now, no technology has been available to help people predict the exact time of the earthquake. Therefore, the safety of people when earthquakes occur almost entirely depends on the quality of the construction works. Because of that, the English builder Elizabeth Hausler has a classic saying: 'The earthquake does not kill, it is the collapsing buildings that kill them'.

According to GS Chu, high-rise buildings are the most sensitive object to earthquakes due to the large difference in height and width, leading to strong fluctuations. Besides, the structure of these works is very complex, so in addition to calculating the seismic resistance in theory, it must also be tested in the earthquake laboratory, studying the reaction to choose a reasonable structural solution.

"Based on the 1996 earthquake partition scale of the Institute of Geophysics, all high-rise buildings in Hanoi are designed to withstand the highest earthquake level of 7 or 8 level , " Professor Tran Chu said. know.

Besides high-rise buildings, public works and works with important economic and political significance such as hospitals, electric stations, television stations are also required to calculate seismic resistance to ensure the seismic The impact only minimizes the operation of these facilities.

For residential buildings built by people with a height of 4 stories or less, the Ministry of Construction is not required to calculate seismic resistance due to the small vertical stiffness, weak oscillation when occurring. earthquake.

According to Professor Tran Chuong, the requirement to calculate seismic resistance for high-rise buildings and public works has been paid attention and fully implemented in recent years, the durability of new construction works in Ha Noi is able to believe.

Although the earthquake in Chile is much more intense than the earthquake in Haiti (8.8 on the Richter scale compared to 7 on the Richter scale), the level of human damage is significantly lower (about 300 people). compared to 250,000 people). The difference in the quality of construction works in these two countries is an important answer to the phenomenon.

'The biggest obstacle to the construction industry in Hanoi today is the 4, 5-floor dormitories such as in Kim Lien, Thanh Cong, Giang Vo ., built before 1990, are now degraded. serious , 'Professor Tran Chuong said. These buildings are mostly large paneled houses, not designed with shock resistance due to being low-rise buildings. In addition to the "overcrowding" over time, the expansion of households makes collective housing unbalanced, very disadvantageous when an earthquake occurs.