Modern construction and maintenance
Precise mobile railway tunnel detection solutions
he TLSD system in a high-speed railway tunnel. Photo: Shanghai Bofa Spatial Information Technology
With the expansion of rail transport, more and more tunnels need to be built and maintained at a high level of safety and performance. Modern projects rely on sophisticated air conditioning and ventilation concepts, low-dust and low-emission working methods and precise measurement technology for inspecting and documenting the status of the structure. At the same time, updated regulations, such as Information 201-067 of the German wood and metal trade association (DGUV), are tightening the requirements for occupational health and safety during track construction work in tunnels.
The TLSD system (Tunnel Laser Scan Detection System) from Shanghai Bofa Spatial Information Technology is used for the precise detection of deformations and the assessment of surface conditions in railway tunnels. It consists of both hardware and software: sensors such as laser scanners, cameras and inertial navigation modules (INS) are integrated on a mobile platform.
The laser scanner module is installed on a measuring carriage and can precisely capture and record tunnel profiles at speeds of up to 15 km/h. It calculates parameters such as diameter (±2 mm accuracy), ovality, ring steps and lips (±3 mm), horizontal distances and clearance profiles (±1 cm).The raw data obtained is seamlessly processed into CAD drawings, Excel spreadsheets or .tiff/.png images.
The camera module uses nine colour line scan cameras with high-intensity LED lights and battery boxes and can capture HD images at speeds of up to 46 km/h. With a resolution of 0.2 mm/pixel, it recognises the finest cracks from 0.1 mm, as well as spalling and leaks. Intelligent algorithms automatically identify 99 per cent of tunnel rings and 97 per cent of segments
Supplemented by the INS module, the TLSD system also provides absolute coordinates and data on track geometry. Two to four people can easily operate the entire system. It is compatible with various types of tunnels and fastenings; the sensor system can also record HD images at high speed.
The TLSD system is suitable for metro, high-speed and conventional railway tunnels. It detects structural deformations, measures geodata, checks for defects, analyses tracks, supports BIM modelling and panoramic roaming. Over 3,000 km of track have already been used by railway authorities in mainland China, Hong Kong and Singapore.
Shanghai Bofa Spatial Information Technology specialises in spatial information technologies for transport infrastructure - more than 20 vehicles are in use with customers in China, Hong Kong, Singapore and internationally. The TLSD has developed from 2D/3D scanners to systems with linear and area array cameras, supplemented by ground penetrating radar and track measurement.
Shanghai Bofa Spatial Information
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