Recently, CRCHI (China Railway Construction Heavy Industry) successfully passed the dual qualification expansion and re-evaluation of laboratories and inspection bodies by the China National Accreditation Service for Conformity Assessment (CNAS), adding the country's only qualification for testing and inspection capabilities of full-face tunnel boring machine (TBM) main bearings. This not only represents a major breakthrough in the testing and inspection of key core components for China's high-end equipment but also signifies that this testing program has officially gained international authoritative recognition, with global validity.

For a long time, the testing of shield machine main bearings has faced challenges such as large dimensions, high load requirements, prolonged validation cycles, and inaccurate monitoring diagnostics, with a lack of effective verification equipment and methods. To address these issues, the research team independently developed the world's largest main bearing operating condition simulation test bench—the only large-scale testing facility in China capable of conducting comprehensive load tests, fatigue reliability tests, and ultimate load tests for large-diameter main bearings. This breakthrough was achieved by innovating key technologies, including load application methods for oversized bearings, electro-hydraulic-mechanical coordinated control, and real-time online condition monitoring systems. The facility has set industry records for the widest testing range, most comprehensive test items, highest loading capacity, and most realistic operating condition simulations.

It is reported that the recent dual accreditations—ISO/IEC 17025 laboratory (Registration No.: CNAS L17944) and ISO/IEC 17020 inspection body (Registration No.: CNAS IB1080)—not only accelerate the industrial application of domestically produced main bearings in tunnel boring equipment but also strongly demonstrate the credibility and authority of China's full-face tunnel boring machine (TBM) main bearing testing system in the global market.

CNAS certification is the highest level of recognition of my country's laboratory testing capabilities, and it is also the only institution in China that can carry out ISO/IEC 17025 and IS0/IEC 17020 international laboratory management system accreditation. The projects that have passed the accreditation this time cover four major areas: full-section tunnel boring machine main bearing test and inspection, full-section tunnel boring machine whole dynamic/static evaluation, metal material performance testing, and industrial oil testing. The test reports issued by laboratories accredited by CNAS (a formal member of the ILAC Multilateral Recognition Agreement MRA) can be mutually recognized in more than 100 countries and international organizations around the world, providing key technical support for my country to improve new quality productivity and assist the high-quality development of high-end equipment, while injecting new momentum into further opening up overseas markets. In the future, China Railway Construction Heavy Industry will continue to increase the construction of an international testing and certification system and provide Chinese-style testing and inspection technology solutions for global high-end underground engineering equipment.