Monitoring

A dense sensor network is installed in the ETH House of Natural Resources to record the behavior of the structure during construction and operation of the building. In particular, 16 load cells permanently monitor the post-tension force in every post-tension cable. Two different systems of optical strain sensors permanently record the strain distribution in the timber frame (FBGs and LUNA). LVDT sensors are used to measure the relative displacement between the timber and concrete interface in the composite floor. An absolute deformation measurement campaign recorded hourly values of the absolute deformation of the composite floor and the post-tensioned timber frame during the construction phase. In the operation phase the absolute deformations are recorded on a monthly basis. Additionally, the moisture content in the timber frame and the bi-axial timber slab is measured on a regular basis.

The monitoring system will record data from the building over a period of several years and hence help to quantify the long-term behavior of the different innovative timber structures.

The monitoring data is continuously streamed to a website (www.ibk.monitoring.ethz.ch/monitoring-projects/honr/). For each measurement quantity a threshold is quantified and an alarm is triggered as soon as the threshold is exceeded. Additionally the alarm is triggered if the data transfer from the local measurement device to the website is not working.