Geotechnical Analyses
Starting from soil profiles, boreholes, and foundation systems, SETAF2018 performs integrated geotechnical analyses including stress diagrams, settlement, bearing capacity, liquefaction, ground improvement, excavation support, and slope stability.
Stress Diagrams and Stress Analyses
Based on boreholes and idealized soil profiles, effective stress, hydrostatic pore pressure, total stress, and horizontal stress diagrams are generated. Capillarity and artesian pressure effects can be included in the analysis.
Load Transfer (Boussinesq / Mindlin–Geddes)
Load transfer calculations are performed through numerical integration of Boussinesq equations.
For piled foundations, load transfer can be evaluated using the Mindlin–Geddes equations.
Assuming a hinged connection between the rigid foundation and piles, moments acting on the pile cap are considered and load distribution to piles is performed accordingly.
Settlement Analyses (Immediate + Consolidation)
For a target point defined at the ground surface, integrated immediate and consolidation settlement analyses are performed for both shallow and piled foundations.
For immediate and consolidation settlements, soil layers can be subdivided into any number of sublayers with user-defined spacing.
Settlement calculations can be carried out for multiple target points.
After the analysis, tables are generated for each sublayer, including effective stress, stress increase, compression, and mechanical properties.
Soil Parameters (Consolidation / Drained–Undrained)
For consolidation settlements, consolidation properties of soil layers can be defined.
For immediate settlements, drained and undrained properties of soil layers can be specified.
Bearing Capacity (Shallow + Deep Foundations)
For defined foundations, shallow foundation bearing capacity is calculated using both total stress and effective stress analyses.
Bearing capacity calculations can be performed using Terzaghi, Meyerhof, Vesic, and Eurocode 7 methods.
For deep foundations, bearing capacity calculations can be carried out using the α, β, and λ methods.
Consolidation Settlement – Settlement–Time Curve
For the point where consolidation settlement is calculated, a settlement–time curve is generated.
A Terzaghi correction can be applied on the curve based on the construction period.
Circular and Polygon Foundations – Numerical Integration
For circular and polygon foundations, stress increases are calculated using numerical integration, and settlement analyses are performed accordingly.
Liquefaction Analysis (SPT-Based) and Improved Soils
Liquefaction analysis is performed based on Standard Penetration Test (SPT) data, and the variation of stress and factors of safety with depth is presented graphically.
Liquefaction analyses can also be carried out for soils improved with rigid columns, such as concrete / reinforced concrete columns, micropiles, deep mixing, jet grouting, and stone columns.
Subgrade Modulus (Shallow + Deep Foundations)
For shallow and deep foundations, vertical and horizontal subgrade moduli are calculated.
Ground Improvement Designs (Jet Grouting / Deep Mixing)
Ground improvement design can be performed using the Jet Grouting method, and bearing capacity and settlement calculations are carried out for jet-grouted systems.
Ground improvement design can also be performed using the Deep Mixing method, where bearing capacity and settlements are determined.
Excavation Support Analyses (Dependent Pressures Method + Staged Construction)
Reinforced concrete piled walls and diaphragm walls can be analyzed. Based on the analysis results, wall displacement checks, anchor soil–grout, tendon–grout, tendon rupture, and internal stability checks are performed. Structural reinforced concrete design checks and overall failure analyses are also carried out. In addition, wall sections for all excavation support faces can be analyzed, stored, and reused.
The software determines pressures acting on the wall using the Dependent Pressures Method (displacement-dependent pressures). Applied loads are derived from deformations, which enables realistic modeling of structural behavior and leads to cost-effective designs. Staged wall construction is simulated accurately by considering the progressive development of deformations and the subsequent stressing of anchors. The method assumes that the surrounding soil or rock behaves like an elasto-plastic Winkler material: in the elastic range it is defined by the horizontal subgrade modulus (kh) and limiting deformations, and when limits are exceeded the material exhibits plastic behavior.
A numerical analysis model is created for all construction stages. Pressures are obtained through iterative calculations, and all steps are solved using the Matrix–Displacement Method. Construction stages suitable for implementation can be defined, and an automatic stage generation option is available to create all stages at once.
Seismic Condition, Surcharge Loads, and Stages
Different ground surface profiles can be defined and used behind the wall. Four types of surcharge loads—point, line, strip, and area—can be assigned behind the wall; these loads can be modified at any construction stage and multiple surcharges can be added. The groundwater level (GWL) can also be updated for all construction stages.
Under seismic conditions, an equivalent static seismic load acting on the wall is determined by multiplying the weight of a selected soil wedge by the horizontal seismic acceleration coefficient. Earth pressures are evaluated using the Dependent Pressures Method (displacement-dependent pressures). Two types of seismic analysis can be performed: either by applying theories that determine earth pressures under earthquake conditions, or by directly applying the equivalent static seismic load to the wall. For seismic earth pressures, the Mononobe–Okabe method is used.
For each construction stage, wall displacements, anchor/soil nail/strut forces, as well as axial force, bending moment, and shear force diagrams are obtained and reported. The software performs SLS and ULS designs based on relevant code factors, reduction coefficients, and displacement limits; displacement checks can be reported on a stage-by-stage basis.
Slope and Embankment Stability (Limit Equilibrium + Optimization)
Slope and embankment stability is evaluated using Limit Equilibrium Methods (LEM), and the factor of safety is determined with the Oms–Fellenius and Bishop slice methods. Soil layers can be defined for any required geometry and included in the analysis using either effective stress or total stress conditions. Support elements such as steel strand anchors and soil nails can also be integrated into the analysis.
The groundwater level (GWL) can be defined for different geometries, and multiple surcharge loads—point, line, strip, and area—can be added. All analyses can be reported, and multiple models can be created within the same project file.
For slope and embankment analyses, both circular and polygon slip surfaces can be defined. Optimization is performed by generating alternative slip surfaces from the initial one, and the slip surface that yields the minimum factor of safety is obtained. The optimization process can be followed as an animation during the analysis.
The model created in the Excavation Support Analysis Module can be converted into a slope model to perform external stability analyses. In addition, retaining walls can be included in slope models using user-defined materials.
