Innovative tunneling machine propels China's modern construction

China's self-developed tunnel boring machine (TBM) with the biggest diameter on Friday achieved a significant milestone by surpassing 3,000 meters in its excavation of a large-scale tunneling project under the Yangtze River, showcasing the country's growing construction capabilities featuring high-speed and intelligent techniques.

The machine, with a maximum excavation diameter of 16.64 meters, was developed jointly by the China Railway Construction Heavy Industry Co., Ltd. (CRCHI) and China Railway 14th Bureau Group Co., Ltd. It is 145 meters long and about 5,000 tons in weight. Its circular cutter's diameter is equivalent to a five or six-story building.

Under the waters of the Yangtze River estuary, the TBM is currently advancing at an impressive average speed of 600 meters per month. This remarkable progress is made possible by the application of a fully upgraded intelligent system in the TBM.

Inside the operator's cabin of the TBM, what once required two or three personnel to manage is now overseen by nobody. A nearby worker can control the entire excavation process with just a flick of a finger, allowing for fully automated and intelligent tunneling operations.

"The previous smart excavation methods primarily focused on controlling the posture of the TBM, requiring manual coordination across various systems. Now, we have all the systems linked together. This makes the process more precise, efficient, and safe," said Xu Weiqing, project manager for the Chongming-Taicang Yangtze River Crossing Tunnel.

Notably, the tunnel lining segments are produced using China's first fully digital production line, increasing efficiency by 20 percent. Furthermore, with the help of self-developed intelligent assembly robots, tunnel components can be assembled automatically at the push of a button, achieving a precision control of up to 0.5 millimeters.

In addition, the intelligent upgrades extend across nine major systems involved in the construction of the TBM tunnel, enhancing processes from design and perception to transportation.

"The nine major systems utilized in tunnel construction have rapidly advanced due to the widespread application of intelligent technologies. This has propelled tunnel excavation engineering forward and ushered in a new phase in tunnel construction technology," said Xie Lili, an academician at the Chinese Academy of Engineering. The Chongming-Taicang Yangtze River Crossing Tunnel, spanning a total length of 14.25 kilometers and connecting Chongming District in Shanghai with Taicang City in east China's Jiangsu Province, features a shield section measuring 13.20 kilometers. Designed for speeds of up to 350 kilometers per hour, it is expected to be operational by the second half of 2029. Upon completion, the tunnel is poised to enable seamless high-speed train crossings under the Yangtze River, holding significant importance for driving development in the Yangtze River Economic Belt.

Innovative tunneling machine propels China's modern construction

Flower breeding and cultivation bases across China are actively promoting new and healthier varieties of flowering trees and plants, helping create a brighter future for the country's famous springtime scenery.

In a peach blossom scenic area in Changde City of central China's Hunan Province, more than 50 varieties of peach blossoms are in full bloom, attracting flocks of visitors.

The varieties in the area come from the national peach germplasm resource bank in the city. Through artificial cultivation, not only are the varieties of flowers increasing, but the flowering period is also being extended.

According to researchers, one of the star varieties, noted for its rich color, took nearly 16 years to cultivate and promote in the scenic area.

"Its biggest feature is its strong resistance to gummosis. We can see that although a branch like this is damaged, there is no gummosis, so it has a long lifespan and can be used in gardens for a longer time," said Wang Yan, professor of the province's Changde Vocational and Technical College.

Gummosis is the formation of gummy substances on the surface of the trees, which often result from dead tissue.

At Phalaenopsis World, the country's largest phalaenopsis tissue culture center in Suqian City in east China's Jiangsu Province, technicians are cutting phalaenopsis seedlings into thin slices and planting them one by one in transparent bottles, allowing them to multiply exponentially.

"The breeding cycle is short, and the light, temperature and humidity can be freely adjusted artificially. The phalaenopsis bred using this technology have high uniformity and fast growth rate," said Wang Yanting, a plant inoculation specialist at the cultivation center.

Researchers said that the planting center uses more than 200 smart sensors and 5G technology to accurately control growth factors such as temperature, humidity, light, and ventilation to achieve "timed flowering."

"In fact, the natural flowering period of phalaenopsis should be from the beginning of the Chinese New Year to early May, and this is its natural state. Now we can intervene with technology and make it bloom any day we want. Phalaenopsis blooms through temperature regulation. At this time, we need to use air conditioning equipment, constant temperature equipment and dehumidification equipment," said Cao Guofeng, director of the cultivation base.

Breeding bases across China promote new spring flower varieties