Measurements and deformation analysis at the banks of the Danube

For more than 30 years the banks of the Danube are under control in order to detect any deformation. These deformations might be due to a changing water balance of the Danube itself and the ground water next to it. Another important fact is the growing traffic in the urban area, mainly on several bridges and also the underground tunnel undergoing the Danube.

Starting in 1964 control measurements were made every second year using the conventional measuring technique like levelling, direction measurements with some old theodolite and distance measurements with subtense bar or tape to mark fixed or control points on the retaining walls next to the Danube. This is the main reason for today’s requirement of accuracy which can be achieved with modern instruments.

The control network covers the area starting at Margaret Island in the north all the way down to the train bridge on the south, on the Buda-side as well as on the Pest-side. The length of this network is approximately 4 km on each side.

Several results had already turned out from the last 30 years of measurements:

1. Whenever some local deformations were detected resulting from the water acting on the fixing of the walls it was reported to civil engineers and the corresponding section was repaired immediately.

2. Rather more important are the efects of the subway which is under the Danube. Here the deformation analysis detected a slight sinking of the whole area around the House of Parliament. This sinking, however, stopped 15 years ago and no further deformation was detectable since then.

3. Also some underground canalisation was causing different problems. It was possible to detect a constant shift in different places.

4. The retaining walls were discovered to be very stable during the last few years and some small movements were detected the explanation for which could be the changing water level.

Дата добавления: 2015-07-19