Climate change leads to more and more torrential rain in Denmark. Flooding where rainwater gets mixed with sewage causes great damage. Therefore water-related projects today represent almost half of the construction market in the country. One example is a new 1.3 km long sewage pipeline to be constructed by Nordvand AS along the strait of Öresund.
The sewage pipeline diameter will be 2.0 to 2.4 meters in order to provide temporary store for large quantities of polluted water and prevent it from discharging into the bathing water of the strait. In the sandy ground an excavation with sheet pile walls is required for laying the pipe. The con-struction phase will generate vibrations affecting buildings along the coastal road as well as breakwaters and embankments.
The order for vibration monitoring has been awarded COWI A/S with INFRA from Sigicom. COWI is a leading Danish multi-disciplinary consulting company with subsidiaries in 22 countries. One specialist service provided is vibration control. The invitation for tenders presented detailed requirements for triaxial sensors, an alarm function with text messages and reporting and web presentation of recordings in accordance with standard DIN 4150-3.
Controlling web application
–15 measurement locations will be established and measurements will be made through the whole construction period of 12–18 months. A mix of INFRA masters with V12 sensors and wireless C12 monitors with built-in logger will be used. Among other features, the small and discrete C12 monitors minimize the risk of vandalism when used in public areas, says COWI´s project manager Jacob Egede Andersen.
With INFRA a comprehensive and convincing combination of hardware and software can be presented. In particular, the customer likes the INFRA Net web ap-plication. The INFRA system is very easy to use efficiently. The ease of supervising the entire instrumentation of a project is important to keep costs low. By the use of INFRA a cost-saving reporting approach can also be provided. All this has enabled us to offer a competitive price, Jacob Egede Andersen continues.
Projects in many countries
–COWI uses INFRA in many different countries, primarily because of its proven reliability, from freezing conditions in Norway, to the desert climate in Quatar and tropical conditions in India”, Jacob Egede Andersen explains.
–In India we have monitored a bridge remotely for three years without a single interruption. Measurements can be con-trolled from anywhere, including our home office in Denmark, using a GSM modem that can be connected to any local GSM provider. The need for local assistance be-comes minimal.
The volume of COWI orders to Sigicom has increased considerably. Jacob Egede Andersen mentions three reasons:
One: More and more projects include monitoring of both noise and vibrations. The ability of the INFRA system to monitor multiple types of disturbances with the same unit has proven to be very cost efficient.
Two: Sigicom has introduced more sensor types. This has opened up possibilities for designing low cost systems for condition monitoring of infrastructure.
Three: For certain applications Sigicom systems are easier and cheaper to use than those of leading competitors. What we would wish is an ability to connect even more sensors to each data logger, Jacob Egede Andersen concludes.