The President of the Association of Structural Engineers of Thailand analyzes 5 risk factors for storms to collapse the roof of a multipurpose shed in Phichit Province, recommending not to stay in the roof structure area when a storm occurs. But should hide in a strong building such as a reinforced concrete building

Prof. Dr. Amorn Pimanmas, Professor of Civil Engineering Kasetsart University and President of the Structural Engineers Association of Thailand Said that from the storm incident, the roof of a multi-purpose shed at a school in Phichit province Collapsed on the evening of May 22, 2023, causing many deaths and injuries.

Causes of building collapses are divided into factors related to storm strength. and the strength of the structure, summarized in 5 factors, namely

summer storm strength For Thailand during the transition from summer to rainy season Approximately during April-May every year, it will be affected by severe summer storms, especially in northern and northeastern provinces. due to the turbulent wind Summer storms are 2-3 times more intense than normal winds, even in a narrow area. in a short time but with high strength can cause the structure to collapse As has happened many times in the past

Physical characteristics of structures that have a large area exposed to wind, such as roof structures or billboards, where the force of the incoming wind will increase according to the area exposed to wind. Therefore, the roof structure has a very long span. There would be more risks.

Structural design does not take summer storms into account. Especially structures built before the year 2007, which standards or ministerial regulations specify that set wind loads for the design of structures in the past. Didn’t take into account the wind power from the summer storm. As a result, the wind force used in the design is 2-3 times lower than the reality.

non-standard construction Observed from the picture of the collapsed building, it was found that Broken concrete pillar and causing the roof to collapse which indicates that the load-bearing strength of the pole is insufficient. The installation of the roof structure is quite high. The sloping of the poles caused the weight bearing capacity to be greatly reduced. So when the wind hits causing the pole to sway And with the heavy weight of the roof structure causing the poles to break The roof structure fell and hit the ground.

The quality of materials and construction may not be up to standard. Observed from the broken concrete into pieces. indicates that the concrete used may have low compressive strength It may be the cause of not being able to bear weight as well.

All 5 factors are just a preliminary analysis. It is possible that the cause of the collapse of the roof structure may be caused by many factors together. Or there may be other reasons involved. all of which Have to wait for the results of the inspection and detailed analysis. And must have information from the actual site, construction drawings, material quality, and scraps of concrete and reinforcement. in order to further analyze the root cause

Prof. Dr. Amorn Phimanmat also stated that summer storms are a serious threat that cannot be underestimated. And there are still a lot of risks during this time. Because it’s still in the changing season. It is expected that there are many more buildings that are at risk. Especially buildings that use the same standard construction. There are also other types of structures that are at risk such as billboards, etc., which are preliminary recommendations for safety. That is, it should not be in the roof area when the storm occurs. But should hide in a strong building such as a reinforced concrete building, etc.

In addition after this incident Relevant government agencies should speed up inspecting the strength of the already constructed roof structure. And must continue to strengthen the building structure according to engineering principles .-Thai News Agency

Source: Thai News Agency