The Innovation Programme together with the Chief Engineers Group organised a lecture by Prof Tong Sun and Prof Ken Grattan of City University London at 25 Canada Square, on 7th April 2015. The lecture was well attended by designers and tunnel engineers with representatives from CEG, C121, C310 and C510.
Prof Tong Sun’s presentation touched on a wide range of Fibre Bragg Grating (FBG) based sensors that measure strain, temperature, force, relative humidity, torque, rotational speed/position, vibration and acoustic sensors. These sensors were innovatively developed to meet industrial needs where other monitoring technique fails short. As a result various types of structures/materials, including concrete, limestone, marine propellers, pantograph and electrical motors, have been instrumented with FBG sensors for both static and dynamic monitoring, with an aim to enhance both the structural reliability and integrity.
The lecture was followed by well-participated Q&A that led to discussions constraint/concerns and lessons learnt of applying fibre optic at Crossrail sites.
Fibre optics technology innovation on Crossrail are:-
- INV00324 – Invested project – C121 – FBG Fibre optic monitoring of SCL in Farringdon and Bond Street
- INV00048 – C310 – FBG fibre optic monitoring of pump station inlet during passage of TBMs
- INV00041 – BOTDR fibre optic monitoring of diaphragm walls (Pudding Mill Lane portal, Limmo Peninsula, Stepney Green step-plate junction, Paddington Station Main box)
- INV00063 – C310 – BOTDR fibre optic monitoring of tunnel segments