Bearing capacity

Road construction sustainability is determined by the form and size of deformity on the road surface under a fore defined static pressure.

Measurement Procedure
The measurement procedure takes place according to the sustainability report documents FGSV. It is carried out by the rear axel twin wheel protruding index arms which are placed upon the tarmac. The index arms, having contact due to the weight of the rear wheels can then detect vertical deformations on the road surface of up to 10cm behind the wheel axle. The form of the evolved cavities and pits is portrayed in up to 100 measurements.
Additionally, the temperature of the bonded pavement as well as the positions of the measured areas are also recorded. An essential requirement for the whole procedure is an absolutely frost free road surface and a tarmac temperature lying between 5°C and 35°C.

The wheel tracks reveal the maximum cavity and pit depths, preservative-segments of similar bearing capability defined and renewal classifications assigned according to the RSTO. A maximum area of 5m² is allocated to each measurement. Due to the dual examination of both wheel tracks, one can be assured that minor carrying capacity differences on the road edges will not be transferred across the whole road width. With knowledge of existing traffic congestion, a prediction of reinforcement measures according to the usage duration is made possible. The evaluation is summarised according to document “Load bearing capacity and road pavement”, FSGV and accordingly the Swiss Standard-670733b “Roadway Maintenance”.

While knowing the layer thickness of the bonded surface paving, the precise recording of the subsidence cavity is possible by retrospectively calculating the E-Modules of the bonded surface paving and lower layer according to the multi layer theory. By taking the traffic congestion into consideration, the characteristical behaviour of the road can then be credibly simulated.

The results are summarised and portrayed in a graphical table. I required, the results can also be exported and Integrated into other GEO information systems.