Area
To find the area you can enter the address by separating the fields with commas.
For example: City, State. Or you can enter the coordinates in WGS84 system. To locate the site, you need to press the search button. The location of the site is an information that is included in the final report.
Soil type (Lithotype)
Soil slopes or Rock slopes.
For rock slope, unlike for soil slopes, the Mohr-Coulomb failure criterion cannot be used to define the resistance of the material; however, with this method can be described a procedure that allows the application of classical Limit Equilibrium methods even for rocky slopes. |
Surface form
The analysis can be conducted for circular surfaces as well as for generic shape/polygonal surfaces.
For circular surfaces should be introduced the grid of the centers, while the polygonal/ free form surfaces must be assigned by points. |
Acceptable level of safety
The data has no influence on the numerical calculation. Based on the value inserted to the software will highlight in various reports (text reports or graphic reports) the surfaces with a safety factor lower than the value set. So it is an indicator of the level of safety that the user wants to keep in reference to the limit state that is verified.
Safety factor search step
This data is important for the search of the safety factor when using circular surfaces. Having a fixed center, the search method of the critical surface is based on the analysis of possible surfaces with variable radius between a minimum and maximum value. The radius variation is done with an incremental step calculated as [(Rmax-Rmin)/Safety factor search step].
BedRock depth
Depth of the rigid layer. The depth is estimated from the minimum ordinate of the profile ( in presence of layers, minimum ordinate of the layers). The search for the critical surface takes place between the typographic profile and the BedRock.
Seismic action
In the pseudo-static analysis the earthquake is computed through the horizontal and vertical seismic coefficients, respectively kh and kv. According to the selected standard is possible to identify the seismic coefficients of the area.
The seismic acceleration is required for the calculation of pore pressure in seismic field.
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Increment of pore pressure
Selecting this option allows you to evaluate the pore pressure generated in the ground in the presence of water table and in conjunction with the occurrence of earthquakes. For the calculation of pore pressure is required to import an accelerogram on which the program automatically calculates the intensity of Arias, the intensity of the intersections with the time axis and the period of Trifunac and Brady (1975). To import the accelerogram click the triangle next to "Accelerogram duration Trifunac": a dialog box opens allowing you to select the file (*.txt, *.cvs) in which is shown the values of the acceleration in [m/s2] and of time in [s]. Here, you can choose the conversion factor of time t and of acceleration a for the automatic conversion of values in the units required by the program.
Following importation, in Parameters, are calculated automatically the values required from processing.
It should be stressed that for the purposes of evaluation of the pore pressure, the user is required to insert additional geotechnical characterization of soils involved in this phenomenon: in the definition of the stratigraphy for each soil type, should be inserted the Additional data.
Partial factors geotechnical parameters
The partial factors that are introduced by the user are factors that reduce the geotechnical characteristics of the soils defined in the stratigraphy.
These coefficients generally apply to the "characteristic" parameters that the user enters in the stratigraphic modeling of soil.
The calculation of the safety factor on the identified surfaces is performed with the reduced parameters of soil strength only if is selected the option "Use these coefficients to reduce the strength of the material".
Partial factor on the resistance
The coefficient reduces the resistance mobilized along the potential sliding surface. The value of the coefficient influences numerically the computation of the safety factor defined by the ratio between the limit strength available and that calculated at the base of each slice. Values greater than unity reduce the available strength of the soil by decreasing the factor of safety.
In the stability analysis, it is advisable to insert a "Partial resistance factor" equal to 1,1 and assign a unit value to the "Acceptable level of safety". With the above assumptions, the user retains a margin of safety on all surfaces that return by a safety factor greater than or equal to unity.
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