IAC News

Hideaki Kamimura
(Obayashi Corporation)

Since 1997, I have been involved in four national road rehabilitation projects totaling 253 kilometers of road in Cambodia and Laos. The following is a table summarizing the projects. This report will cover projects (1) to (3).

(1) Rehabilitation project of National Roads 6 and 7 in Cambodia (1997 to 1999)
This project was complete rehabilitation work covering 75 kilometers of the national road connecting Phnom Penh and Kampong Cham province. In July 1997 under circumstances of political unrest, Cambodia was a country in which party rivalry was intense and it was unsafe to live and work there, with gunfire all around. Because of this, we expatriate staff tentatively evacuated to neighboring Thailand. Even when the project resumed, the country remained unsafe, and we oversaw the construction efforts under the watchful eye of armed security. Measures against the risk of land mines were also essential. At the time, there was not a lot of traffic in Cambodia, and the road design consisted of only one top layer of 5 cm-thick asphalt paving. Later, in 2001, traffic began to increase with the opening of the Mekong River Bridge in Kampong Cham. Back then, even Phnom Penh, the capital, did not experience congestion like it does today.

(2) Rehabilitation project of National Road 9 in Laos (2000 to 2002)
This was a project to improve a six-meter wide road into twelve-meter wide asphalt paving. All the work, from production of crushed stone to laying the asphalt paving, was conducted by efforts under a direct employment system. The first job was to find a quarry for stone materials for use in the road rehabilitation. After searching about twenty potential mountains with the persons in charge on the Laos side and repeatedly conducting rock drilling investigations in the jungle, only then did we find a quarry that provided a sufficient volume of stone reverses. During the work to build an access road to the quarry, we encountered unexploded ordnances (UXO) that had been dropped during the Vietnam War. While a total of 450 unexploded ordnances were discovered, the Laos military found and disposed of them, enabling us to produce crushed stones without any accidents. As it was a nine-kilometer-long access road within an untouched forest with poor water drainage, the road would quickly become muddy when it rained, suffering maintenance of the road during the day and night throughout the rainy season.
By making a 73-kilometer-long detour road  (the bridge parts were Bailey Bridges) along National road, the national road construction work could be done across the entire road in one go, reducing the number of construction joints and improving the quality of the work. The national road was located in low-lying areas such as in the rice field, and so huge effort was spent on maintaining the detour road during the rainy season.
In 2002, Takao Kawakami, Preside of JICA, visited the Seno Intersection during its construction. I got to hear in detail about the technical transfer to the local people, and he praised Obayashi’s efforts for the road construction work done by hand as a result of the technical transfer through direct control of local Laos construction workers and engineers. Some photos taken of the construction site have become commemorative postage stamps.

(3) Rehabilitation project of National Road 9 in Laos (2012 to 2015)
In 2007, with the opening of the Second Mekong International Bridge connecting Thailand and Laos in Savannakhet, the restriction on the axle load of vehicles was raised from 9 tons to 11 tons. This resulted in an increase in the amount of heavy vehicle traffic, with existing damage to National Road 9 (the road remained a nine-ton axis load design) becoming more prominent. This led to an order being placed for road repair works. The scope was the rehabilitation for 58.1-kilometer road including the aforementioned 40-kilometer Obayashi section. We received repeated criticism from the Engineer saying that the problems were a result of Obayashi’s construction work from the previous project. As I anticipated that the real reason behind the road damage was overloaded vehicles, I took the decision as the project manager to place our Laos staff at the weight checkpoints 24 hours a day to monitor the weight of vehicles across the 93-week construction period. The collected data (details such as overloading and so on of approximately 40,000 trucks) was shared with the Department of Roads,  Ministry of Public Works and Transport (MPWT), Embassy of Japan in the Lao PDR, and JICA towards the later stages of the construction work. This information was also shared with the Engineer in the monthly report. At the time, we received praise from JICA senior advisor Moriyasu Furuki (former Executive Director of JSCE), stating, “This is very valuable data showing the reality of vehicle overloading in developing countries including Africa.” We held a joint presentation about this at JSCE’s annual conference event.

In August 2013, when visiting the construction site, JICA President Akihiko Tanaka was impressed with the hand-built monument of the previous construction project (completed in 2002), declaring, “This is meticulous work.” 

Later, in 2016, in response to cracks in the road surface that occurred during the defect liability period, I returned to the site and carried out pavement repairs by milling and overlay. At this time, I did all the asphalt mixing design work (including aggregate testing) myself.

According to agreement of the Ministry of Public Works and Transport, the issues of controlling overload vehicles was recently transferred into Department of Roads (DOR) instead of Department of Transport (DOT). It seems that measures against overloading are being implemented nationwide in Lao under the new organization.

The bridge that was used for the design of the 200-riel note in Cambodia

An unexploded ordnance discovered from the quarry access road (my helmet is on the side)

Damage to old paving as a result of use by excessively heavy vehicles (vehicles from Vietnam)

Overloaded trailer transporting blocks of wood
(broke down in the center of the road due to the vehicle being too heavy)

Construction monument visited by President Tanaka (made using quarry stones)

【Reported by Hideaki Kamimura, Civil Engineering Construction Project Department, 
Asia-Pacific Regional Head Quarters, Obayashi Corporation】