Rama IX Bridge (, , ) is a bridge in
Bangkok
Bangkok, officially known in Thai language, Thai as Krung Thep Maha Nakhon and colloquially as Krung Thep, is the capital and most populous city of Thailand. The city occupies in the Chao Phraya River delta in central Thailand and has an estim ...
,
Thailand
Thailand, officially the Kingdom of Thailand and historically known as Siam (the official name until 1939), is a country in Southeast Asia on the Mainland Southeast Asia, Indochinese Peninsula. With a population of almost 66 million, it spa ...
over the
Chao Phraya River
The Chao Phraya River is the major river in Thailand, with its low alluvial plain forming the centre of the country. It flows through Bangkok and then into the Gulf of Thailand.
Etymology
Written evidence of the river being referred to by the ...
. It connects the
Yan Nawa
Yan Nawa or Yannawa (, ) is one of the 50 districts (''khet'') of Bangkok, Thailand. The district is bounded by (clockwise from west to northeast) Rat Burana (across Chao Phraya River), Bang Kho Laem, Sathon, and Khlong Toei Districts of Bang ...
District to
Rat Burana District as a part of the Tha Ruea – Dao Khanong Section of
Chaloem Maha Nakhon Expressway.
The bridge was named in the honor of King
Bhumibol Adulyadej
Bhumibol Adulyadej (5 December 192713 October 2016), titled Rama IX, was King of Thailand from 1946 until Death and funeral of Bhumibol Adulyadej, his death in 2016. His reign of 70 years and 126 days is the longest of any List of Thai mo ...
's 60th birthday. The opening date coincided with the king's birthday, with a million people walking over it.
[''Beanz means Hines / Peter Hines — the worldwide civil engineer'' pages 17 and 18.] It was the first
cable-stayed bridge
A cable-stayed bridge has one or more ''towers'' (or ''pylons''), from which wire rope, cables support the bridge deck. A distinctive feature are the cables or wikt:stay#Etymology 3, stays, which run directly from the tower to the deck, norm ...
in Thailand
and had the second-longest cable-stayed span in the world when it opened in 1987.
The original colour scheme, with white pylons and black cables, was replaced with an all yellow scheme representing the king in 2006.
A new eight-lane double-pylon cable-stayed bridge paralleling the Rama IX Bridge has been under construction for some time. Part of the Rama III-Dao Khanong-Western Bangkok Outer Ring Road expressway project, it is intended to relieve traffic congestion on the existing single-pylon bridge. The new bridge's official opening will be in early 2024, after which the Rama IX bridge will be closed for an extensive renovation, which includes a sensor system for added safety.
Bridge structure
The steel superstructure includes the bridge, rigged mast, and cable. The main span of the bridge, which is stretched between two poles, has a length of 450 meters. The main span is a trapezoid 33 meters wide. The bridge has a walkway along its side. The bridge has two main pylons 3 meters × 4.50 meters. This serves to hold the tension of the cable and weight into the pylon pier. The 121 – 167 mm diameter cables consist of many small wires wound together. The cables vary in length from 50 to 223 meters can absorb the tension for 1,500–3,000 tons.
Approach viaducts
The gradually sloping viaducts on each side of the river are dual-double-T,
post-tensioned, concrete structures with thirteen 50-metre double spans on each bank cast in-situ with a steel travelling shutter, up to 40 metres above the ground for sufficient shipping clearance.
The senior engineer
Peter Hines[26 January 2021 obituary and his photo on page 27 of London's ]Daily Telegraph
''The Daily Telegraph'', known online and elsewhere as ''The Telegraph'', is a British daily broadsheet conservative newspaper published in London by Telegraph Media Group and distributed in the United Kingdom and internationally. It was foun ...
. overcame a major construction problem: ''On releasing the 950-ton travelling shuttering, the suction of the shutters could pull the new concrete off. I suggested that as we were only carrying the dead load at the time, we should
stress the work to about 2/3rds the finally required stress so that the material would not “hog” (rise in the middle) so much – this worked well. After removing the shuttering, we applied the full stress.''
See also
*
King Bhumibol Adulyadej
References
External links
*
{{DEFAULTSORT:Rama 9 Bridge
Road bridges in Bangkok
Cable-stayed bridges in Thailand
Bridges completed in 1987
Crossings of the Chao Phraya River
Yan Nawa district
1987 establishments in Thailand