At the First Session of the 13th Beijing Municipal Committee of the CPPCC, member Yu Le proposed developing specialized construction machinery to overcome technical challenges in deep underground engineering, break through 35-meter underground space, and lead the expansion of urban underground space toward greater depths.
Member Yu Le noted that Beijing's urban space has already expanded underground. Construction technologies for subways, large municipal pipelines, underground parking garages, and underground commercial facilities have developed rapidly, accumulating extensive practical engineering experience and achieving considerable progress, fully meeting the needs of underground space construction within a depth of 35 meters.
Yu Le stated that there are currently no effective technical means for sealing off high-pressure deep groundwater. Below 35 meters, Beijing is mainly composed of highly permeable sand and gravel strata with abundant groundwater, and confined water pressure exceeds 10 meters. Traditional dewatering methods are not feasible, and there are no mature technical means for water blocking. The level of deep underground construction equipment is low. China has become a major manufacturer of construction machinery, but few enterprises have engaged in the research and development of specialized equipment for underground engineering. Operations remain in a primitive state characterized by high manpower requirements, high labor intensity, and high operational risk.
In addition, research on key technologies for deep underground construction has stagnated, with insufficient reserves. "In 2011, when I was interviewed by a media outlet, I raised concerns about the prospects of subway construction: the mined method has been developed in certain stages of China's subway construction, but its working environment is harsh, the degree of mechanization is low, labor intensity is high, and risk is great. It will face a technical development bottleneck in five years," Yu Le said. "At present, this problem has already surfaced. The key issue is that the industry has not yet recognized its severity, and research in this area is rarely reported."
Therefore, he proposed overcoming technical challenges in deep underground engineering and leading the expansion of urban underground space toward greater depths. Through government advocacy, financial support, talent organization, and innovation, efforts should be made to overcome the technical challenges of groundwater sealing, develop specialized construction machinery, improve the degree of mechanization, initiate on-site engineering tests, and explore and accumulate experience, so as to build technical reserves for constructing deep three-dimensional interconnected rail transit, underground roads, utility tunnels, large parking garages, rainwater regulation pipe networks, civil air defense works, and other projects, and to lead and promote the expansion of urban underground space toward greater depths.