Weight lot
A weight plumb bob (also known as a pendulum plumb bob) is, similar to the swimming plumb bob, a permanently installed plumb line to determine the plumb line and its deviations for ongoing structural monitoring in dams .
construction
Like a pendulum , it essentially consists of a weight that is attached to a wire and centrally suspended from a fixed point in the top of the wall and via a hole leading vertically downwards .
The solder wire leads through this hole to a space in the foot area of the dam. In order to dampen any plumbing vibrations that may occur, the tension weight hangs in a container filled with water or oil.
The position of the solder wire is determined via at least one reading device installed above the container. This takes place in a horizontal plane in two directions that are normal to one another. Further reading horizons above can also be installed, which then not only enable the relative displacement measurement of the wall crown, but also intermediate points, which thereby allow an approximation to the bending line of the dam.
Solder wire lengths of up to 100 m and total accuracies of up to 1: 200,000 can be achieved. A coordiscope can be installed for manual measurement and a telelot for automated measurement.
literature
- Heribert Kahmen: Applied Geodesy: Surveying. Walter de Gruyter, Berlin 2006, ISBN 978-3-11-018464-8 .
- Peter Rißler: dam practice. R. Oldenburg, Munich 1998, ISBN 978-3-486-26428-9 .
- Konrad Bergmeister , Frank Fingerloos, Johann-Dietrich Wörner: Concrete Calendar 2011: Power Plants, Fiber Concrete. Ernst & Sohn, Berlin 2011, ISBN 978-3-433-02954-1 .