The world's first wheel-rail subway tunnel structure inspection vehicle was rolled off the assembly line and successfully delivered at Tangjiatuo Station in Jiangbei District on December 27. It was developed by Shanghai Tongyan Civil Engineering Technology Co., Ltd. and produced by Chongqing Tongyan Dongmai Information Technology Co., Ltd. 

The world's first wheel-rail subway tunnel structure inspection vehicle was successfully delivered at Tangjiatuo Station in Jiangbei District on December 27. (iChongqing file photo)

From Zhu Hehua, academician of the Chinese Academy of Engineering and professor of Tongji University, the expert group agreed that the wheel-rail subway tunnel structure inspection vehicle has generally reached the advanced international level, filling the gap at home and abroad. It has major economic and social benefits and broad application prospects in the industry. 

The research and development of key technologies and equipment for tunnel maintenance have been listed high on the agenda of the National Medium- and Long-Term Plan for the Development of Science and Technology (2006–2020). This world's first tunnel inspection vehicle invented different technologies to solve various complex problems.

For example, aiming at the problem of rapid detection of microcracks and crack depth in subway tunnel structures,  non-contact laser ultrasonic detection technologies were invented with a positioning accuracy of 1cm. For the problem of high-precision positioning in subway tunnels, it used automatic structural feature identification and proposed a calibration method for time series reverse correction of encoder mileage.

The staff is operating the inspection vehicle. (iChongqing file photo)

The project has particularly created many global technical pioneers, ranging from non-contact detection technology for tunnel structure crack depth and shallow potential spalling, wheel-rail subway tunnel structure multi-function detection equipment, to point-one-ring section comprehensive quantitative evaluation method.

Chongqing Tongyan Dongmai Information Technology Co., Ltd. in Chongqing Gangcheng Industrial Park is a key investment promotion project in Jiangbei District. A national-level tunnel engineering laboratory will be built there in the next step. The scientific project named Research and Development of Key Technologies and Equipment for Rapid Inspection and Evaluation of Transportation Infrastructure will be carried out. Its total investment is worth 50 million yuan, and it will inject new vitality into the development of rapid inspection technology for transportation facilities.