More than 400 electric poles collapsed after Typhoon No. 5: Temporary use of post-tensioning columns | Society



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According to initial statistics from TT-Hue Power Company, Storm No. 5 passed through the area, causing the breakage of 408 power poles of all kinds, affecting more than 280,000 customers and 2,050 transformer stations … After many days of full force practice to overcome, at noon on September 21, the entire province of TT-Hue returned power to more than 85% of customers; Particularly in the city of Hue, the electricity replenishment rate is almost 100%.

More than 400 electric poles collapsed due to typhoon level 8: Temporary use of post-tensioning columns - photo 1Power poles broke into 3 sections due to Typhoon No. 5 (Typhoon Level 8) unaffected by trees in TT-Hue.

In Typhoon No. 5, what worries the public and the people is that many power poles were broken, they fell apart, a kind of damage caused by rare natural disasters. The columns, when broken, reveal a small steel, gently cut; unbuckled, bent, exposed 16-18 size steel core like traditional electric poles before. The number of power poles damaged is also said to be unprecedented after a natural disaster in TT-Hue over the past 10 years.

More than 400 electric poles collapsed due to typhoon level 8: Pause using the post-tensioning column - photo 2Do people suspect that electric poles are broken due to lack of quality?

According to TT-Hue Power Company, in design, the power poles put into use can withstand the wind of a 12 degree storm. The type of prestressed centrifugal column used by this unit is a good product for bearings, it has been tested and sealed. to meet Vietnamese standards (TCVN). Before leaving the factory, the products have passed stress tests, endurance tests and destruction tests. This type of column is designed to withstand twice the expected force of actual impact.

However, according to the PV report, in fact, storm No. 5 that passed through TT-Hue on the morning of September 18 only had winds from level 6 to level 8, with a maximum shock of level 11. With such However, in the entire province of TT-Hue, there are 408 power poles that have been broken, many of them have been separated from their bodies.

This is what makes the public, people wonder about the strength of the post-tensioned centrifugal casting column. Many opinions suggest, for natural disaster areas like Hue, it is necessary to use “special” power poles that can withstand the impact of large storms, but cannot match a TCVN type between provinces and cities.

More than 400 electric poles collapsed by typhoon level 8: Suspension of post-tensioning columns - photo 3TT-Hue Power Company explained, it is a post-tensioned centrifugal concrete casting column that complies with the TCVN 5487: 2016 standard, assessed by the General Department of Standards, Metrology and Quality and announced by the Ministry of Science and Technology.

Explaining the many damaged post-tensioned centrifugal posts, Mr. Ha Thanh Long, Director of TT-Hue Electricity Company, said: The reason for such a situation is due to the unforeseen ability to support trees. green falls on the electric pole system. The series of trees that fall to the power lines is the cause of the great damage to the pole system.

However, through PV research, there are places in the middle of the field where the copper is not bare, it is not affected by the trees, the “standard” prestressed centrifugal column is also “cut” by the storm. Mr. Ha Thanh Long went on to explain: The prestressed centrifugal copper column between the copper broke due to the domino effect, once there were inclined columns in the power line, the column that had the highest load capacity would break or collapse.

More than 400 electric poles collapsed due to typhoon level 8: Suspension of post-tensioning columns - photo 4The electric pole fell inside the village house.

Prestressed centrifugal power poles are said to resist forces well, but have brittle properties in consultation with experts; while the traditional cast column has plastic properties. When affected by strong external force, the prestressed centrifugal column will fracture, while the traditional electric column is “flexible column”, so it is deformed, if broken, it is difficult to split, the “gut” is designed with steel. are larger than the post-tensioning column.

More than 400 electric poles collapsed due to typhoon level 8: Pause using post-tensioning columns - photo 5People were surprised by the electric poles “cut” by the wind, and there was no large steel core inside.

Currently, the provinces and cities of Vietnam use a series of post-tensioned centrifugal electric poles, as it is a product that complies with the Vietnamese Standards assessed and announced by the authorities, with a cheaper price of 5-10% compared to the traditional column ; When put into use, it will significantly save investment budget costs.

More than 400 electric poles collapsed by typhoon level 8: Suspension of post-tensioning columns - photo 6EVN leaders have requested to suspend the use of post-tensioned centrifugal columns for reevaluation.

However, many people believe that given the increasingly complicated climate, regional characteristics related to climatic factors, weather and storms are also very different, especially in the region. Trung; Therefore, this is something that needs to be considered and reconsidered in using the correct type of pole.

Given the above situation, the leaders of Vietnam Electricidad have just asked their affiliated units to re-evaluate the use of post-tensioned centrifugal electric poles; In the short term, stop using these columns and calculate and install the columns to ensure storm resistance.

EVN leaders also asked the group’s departments to study the proper use of power poles in storm-prone areas and then propose standards for units to implement.



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