In the article Author characterized the calculating conditions of boundary slope coefficient of critical scour line below hydraulic structures, used to estimation of the buildings safety. Boundary values of these coefficients were computed for two schemes: equivalent stability, range active tensions zone. The field studies were made for different hydrological, hydraulic and exploiting conditions, so the time was the only independent factor. Computed coefficients of critical line and some of the result of field study are compared. The safety states of analysed objects in different stages of their exploitation were defined after the comparison of real coefficients witch took of field measurements with counted values. ...
Apart from basic model test of hydro technical structures, more often in hy-draulic laboratories experimental works are conducted devoted to the recognition of water flow conditions through various environmental water structures. This kind of research concerns chosen situations accompanying water flow in blurred alluvial troughs, covered with flora, taking fish movement into consideration, on permeable stone constructions, prototype devices, aerators or swirl chambers. From such research we gain fast, often pulsating pressure changes and accompanying them pulsating of flow velocities. They require usage of modern techniques and measuring devices, that utilise high frequency electromagnetic and acoustic impulses. They are also used in field studies as a source of signals for the systems supporting objects' exploitation activities. The majority of national institutes have hydraulic laboratories well-equipped with similar category measuring devices. These are often the same models of meters. It is thus necessary to establish coherent research and result interpretation standards. In the article the meters of water flow velocity used in SGGW Hydraulic Laboratory are described. The principles of these devices' configuration are presented as well as their connection to computer research system of the laboratory. Configuration of measuring apparatus depends on the kind and value of collected data, their ...
