ABRUPT WATER PRESSURE VARIATIONS IN PERMEABLE SOILS

Abstract

It is the condition of up-to-date dimensioning of hydraulic structures to take into consideration all effects with their real value. That is why the investigation must be expanded to the hydrodynamical phenomena which occur due to an abrupt pressure head variation. Formulae were derived to determine the transition time of pressure variations and the velocity of a hydraulic bore. The formulae were verified by experiments. It can be established that in soils with a different permeability coefficient aperiodical pressure variation forms due to abrupt pressure variation. This abrupt variation does not cause a dangerous surplus dynamical load. One could also see, that the velocity of a hydraulic bore is about one hundredth of the velocity in systems, filled with pure water. The hydraulic bore does not cause a phenomenon or load. similar to those caused by a water hammer.