Tunnels are an essential and growing part of our infrastructure all around the world. Since it is hard to estimate how long time a certain tunnel will last, and be safe to use, there is also an increasing need to continuously estimate the status of our tunnels. If not maintained, tunnels will not only cause delays and grievance, but also lead to human health problems, unnecessary injuries, and in extreme cases even loss of lives. Safe, efficient, and constant evaluation of all our tunnels is therefore needed.
The rate in which a tunnel is deteriorating is dependent on many different factors, such as environmental, geological, materials used, construction method etc. Life span estimations are unreliable. Unexpected and untimely problems are common. Some of the problems include movements in bedrock causing fractures in tunnel lining, water seepage and other structural defects. Voids and lining separation may collect water causing stress and failure, especially during winter climates. Rapid and precise evaluation methods and tools are therefore needed.
The methods in which a tunnel can be inspected vary to a certain extent with what kind of tunnel and what purpose the tunnel fulfils but a non-destructive and rapid method is preferred. Common methods include direct and mechanical methods, infrared thermography, multi-spectral, ultra-sonic methods, and Ground Penetrating Radar (GPR).
Due to advances in GPR development, the GPR method is in many areas around the world quickly becoming the preferred method for tunnel investigations. GPR is an easy-to-use, non-invasive, rapid and light-weight method. It can successfully detect and track fractures, both in lining and in the bedrock behind. GPR can locate risk zones, such as locating areas where lining separation and corrosion is present. GPR gives in most cases instant results at site, whereas other methods usually need more thorough and tedious evaluation.
Guideline Geo provides a number of different solutions to help you inspect and ensure safe tunnels. Please contact us to discuss how we can support you!
Tunnel Inspection in China using a MALÅ GPR system