The CSRME Actively Carries Out Scientific and Technological Services, and Organized a Series of Meetings for Evaluating Scientific and Technological Achievements

Recently, the CSRME organized a series of meetings for evaluating scientific and technological achievements.
On April 15, 2022, the meeting for the evaluation of scientific and technological achievements - "Key Technologies and Applications of Safe Construction of Large Underground Spaces in Cities" organized by the CSRME was held in Beijing (online + offline). This project was initiated by China Railway Construction Corporation Limited, and cooperates with China Railway First Survey and Design Institute Group Co., Ltd., China Railway Fourth Survey and Design Institute Group Co., Ltd., China Railway Eleventh Bureau Group Corporation Limited to build a research and development team. For solving the major scientific and technological problem of "key technologies and applications of Safe Construction of Large Underground Spaces in Cities", the innovative achievements obtained are as follows: 1. The method and system of construction dynamic risk assessment, data traction prediction and multi-index early warning were constructed through analyzing the multi-factor coupling and dynamic evolution of risks in urban underground large space construction. The risk pre-control method of safety pre-position was improved, and the multi-dimensional quality evaluation standard of urban underground space was developed for the first time, which provides a theoretical basis for the risk pre-control for safe construction of urban underground space. 2. For the urban networked underground space, based on the interaction and extension mechanics among "structure-strata-environment", a classification method for evaluating the degree of disturbance and the key technologies for safe extension are formed, which created development methods and technical system for a network of large underground spaces in cities. 3. The integrated micro-disturbance safety construction technology of pipe roofing pre-built structures in urban underground large spaces has been improved. The supporting structure and construction technology that can realize rapid assembly is developed, and the new structural system and key construction technology of urban underground large space micro-disturbance rapid support has been improved. Construction key technology. 4. The intelligent equipment for in-pipe cutting and welding of the prefabricated structure of the pipe roofing was developed, the three-arm six-degree-of-freedom multi-functional trolley for the prefabricated support structure and the integrated machine for quick assembly and support of urban construction and excavation were also developed, and a construction safety visualization Intelligent monitoring platform was established. The above research results have been successfully applied in more than 40 urban underground space construction, reconstruction, and extension projects, including the Wuhan Optics Valley Plaza Complex Project and the Taiyuan Yingze Street Underpass Project, with significant social and economic benefits.
On April 21, 2022, the CSRME held a meeting to evaluate the scientific and technological achievements of China Railway 14th Bureau Group Corporation Limited. The project "Safe and Efficient Driving Technology for Large-diameter Shield Tunnels with High Water Pressure and Complex Geology" is led by the China Railway 14th Bureau, cooperated with the Large Shield Company, a subsidiary of China Railway 14th Bureau, and Southwest Jiaotong University to carry out in-depth research on the following three aspects for solving the technical difficulties in safe and efficient tunneling control, precise crossing control, and green disposal of waste mud: (1) Adaptive design of shield tunneling machine and perception of cutting tool working status; (2) Safe excavation of large-diameter mud-water shield in high water pressure and strong permeable stratum; (3) Environmental protection treatment and improvement of waste slurry in shield tunnel. The optimal parameter ratio of film-forming mud slurry, a reasonable range of mud pressure support ratio, water-resistant dispersion technology of synchronous grouting slurry and tool improvement technology were used as guidance for the construction of a long-distance river-crossing tunnel through high water pressure and highly abrasive formations. Using the decision-making method of atmospheric pressure cutter head tool replacement timing, tool wear reduction design technology, tunneling parameters control method and online monitoring system, it has solved the problem of oversized foundation pits and long-distance crossing of water-rich sandy ground. The high-efficiency treatment technology of waste mud that combines weak acid blending, flocculation conditioning, and physical filtration aids was adopted, and a new process for the joint preparation of synchronous slurry from mud-water shield waste mud and screening slag was adopted, which realized the on-site resource utilization of waste slurry and avoided the need for the pollution of water resources realized green construction.
On April 21, 2022, the scientific and technological achievement evaluation meeting of "Key Technologies and Applications of Metro Shield Tunnel Construction through Complex Sea Areas" organized by the CSRME was held in Beijing (online + offline). Xiamen Rail Transit Lines 2 and 3 are the first batches of sea-crossing subway tunnels in China, which are extremely complex in traversing geology, face high water pressure, strong corrosion, slow driving speed, fast tool wear, difficult replacement, and the construction of communication channels by seabed freezing method. A research team established by Xiamen Railway Construction and Development Group Co., Ltd., China Railway Fourth Survey and Design Institute Group Co., Ltd., State Key Laboratory of Shield and Tunneling Technology, Southwest Jiaotong University, Nanjing Water Conservancy Research Institute, Tongji University, and China Railway 14th Bureau Group Corporation Limited. Its goal is to conduct in-depth research on the worldwide problem of subsea tunnels, including structural selection and seismic design, durability design, shield machine configuration, accurate prediction of tool wear, subsea warehousing with pressure, and construction of communication channels by seabed freezing method, long-term health monitoring and evaluation, and has achieved a series of innovative results. These innovations have been successfully applied in the design, construction and operation of subway shield tunnels under the complex environmental and geological conditions of Xiamen Sea, and have been successfully promoted in other projects, with significant economic and social benefits.