First Tunnel over 10,000 Meters of China-Laos Railway Completed

Construction of the Wanhe Tunnel of the Yuxi-Mohan section in Southwest China's Yunnan province was completed on March 13, ten days ahead of schedule.

It is the second-longest and the first over 10,000-meter tunnel to be completed along the China-Laos Railway.

Contracted by China Railway 12th Bureau Group Co., Ltd. and supervised by China Railway Fifth Survey and Design Institute Group Co., Ltd., the 17,441-meter tunnel is the longest in the project built by an individual company.

The section was difficult to build because of complicated geological conditions which required digging through the soft rock deformation strata. Going under the Kunming-Mohan Highway also added to the engineering difficulty.

Builders adopted the TSP advance geology forecast system as well as deepened blast holes and a deeper lead horizontal borehole and adjusted support parameters to dig through the soft rock deformation strata.

Innovations were also developed. Eight patents for utility models were obtained, and seven new skills contributed to high-quality engineering.

Security of the tunnel construction was managed and supported by informatized measures, and closed circuit television systems were installed to guarantee real-time positioning and 24/7 monitoring and emergency alerts.

Technologies including BIM modeling, a WeChat QR code and notice boards of engineering operation and disclosures also greatly lessened danger and alarms during the construction.

It's worth mentioning that the project department urgently made emergency plans, adjusted the construction schedule and established a joint prevention and control system when the COVID-19 epidemic broke out.

To guarantee the project schedule, experienced local technicians were recruited and peak operation times were arranged.

Starting from the Yuxi Station of the Kunming-Yuxi railway and terminating at the Mohan Port at the China-Laos border, the 507-kilometer Yuxi-Mohan section is a main international railway passage connecting China with Laos and Thailand.

It is also a major infrastructure that will improve Yunnan's participation in China's Belt and Road Initiative and promote connectivity between China and the neighboring countries.

As for the China-Laos Railway, it is a key project of Belt and Road construction as well as a main part of the central line of the Trans-Asian Railway.

A builder of China Railway 12th Bureau Group Co., Ltd. works in the tunnel after construction is resumed. [Photo/sasac.gov.cn]

The No. 3 inclined shaft of the Wanhe Tunnel [Photo/sasac.gov.cn]

(Executive editor: Wang Ruoting)