The general data refer mainly to the river pole to be analyzed. For this purpose, the following general data are defined:

DATA RELEVANT TO THE POLE

Upstream pole level [m]:

It is the level, with respect to a reference horizontal plane, of the upstream (highest) point of the river-bed stretch one wants to arrange;

Downstream pole level [m]:

It is the level, with respect to a reference horizontal plane, of the downstream (lowest) point of the river-bed stretch one wants to arrange;

Pole length [m]:

The distance, measured along the projection of the pole on the reference horizontal plane, of the starting point of the pole (upstream point) and the final point of the pole (downstream point);

Width of the river-bed section [m]:

The river-bed section is assumed in the WEIRS programme as a rectangular section and consequently the width of the river-bed section coincides with the base of the rectangular section assumed for moulding the river-bed section;

Average diameter of the material constituting the river-bed [m]:

The diameter passing by 50% through the sifting test on the soil constituting the river-bed;

D90 [m]:

Diameter passing by 90% through the sifting test on the soil constituting the river-bed:

Design flow rate [m³/s]:

Design flow rate determined on the base of the hydrologic features of the basin inside which the pole to be analyzed is contained;

Manning’s n value [-]:

The roughness factor of the river-bed bottom used in the formula of the uniform motion for open channels. As a rule, it takes values included between 0.011 and 0.035;

SAFETY FACTORS

Overturning safety factor:

It is the minimum ratio admitted between the stabilizing moment and the overturning moment;

Sliding safety factor:

It is the minimum ratio admitted between forces which tend to stabilize by slipping and forces which tend to destabilize by slipping;

Limit load safety factor:

It is the minimum ratio admitted between the limit load of the foundation and the load transmitted by the weir in working conditions.

General data

General data

DATA RELEVANT TO THE POLE

SAFETY FACTORS