Thai engineer confirms the safety of Phra Nang Klao bridge

In response to buzzing speculation concerning the slim pillars of Phra Nang Klao Bridge, a key project engineer confirmed that the bridge is indeed designed to global engineering standards. The suspicion arose last Thursday when a Japanese holidaymaker posted a photo of the bridge on Twitter, voicing fears about the slender columns.

The post sent ripples through the online community, being retweeted more than 8,000 times and viewed by 13 million people. This sparked a contentious debate on Thai construction safety, with widespread apprehension voiced regarding the pillars’ stability during earthquakes.

Patthanapong Thongsuk, an engineer who closely supervised the project, assured the press of the safety and sturdiness of the structure.

Thongsuk reiterated that the bridge design meets regulatory compliance as set by the Thai Department of Highways as well as the international AASHTO (American Association of State Highway and Transportation Officials).

He elaborated that the base of each pillar spans approximately 80 centimetres in thickness and 410cm in width. The height of the columns can range from 10 to 15 metres. The design of the bridge includes allowances in joint spaces allowing for natural contraction and expansion due to thermal effect.

The structural engineer further explained that thin pillars offer greater flexibility in supporting changes due to variations in temperatures. Comparatively, larger columns bear a significantly higher weight, owing to their rigidity.

Chavalert Lertchavanakul, a high-ranking technician from the Department of Highways, corroborated Thongsuk’s claim when he confirmed to a popular radio station that the bridge and its pillars can safely bear vehicle weight and are impervious to tremors.

Lertchavanakul highlighted that the column design, which came into practice in 2015 following a proposal by Norwegian civil engineering company Norconsult Aasjakobsen, has been effectively implemented in other Thai bridges. Additionally, he stressed that the Phra Nang Klao Bridge has been in operation for several years without any incidents.

Anek Siripanichgorn, an adviser to the Engineering Institute of Thailand, further propounded the reliability of the controversial design. He stated that these slim columns present a safer alternative during earthquakes compared to their thicker counterparts. He substantiated his claim by indicating that similar designs are widely used in Japanese infrastructure, reported Bangkok Post.