The Use of Undisturbed Samples (UDS) in Numerical Modeling (PLAXIS, Geo5, MIDAS GTS)
In geotechnical engineering, accurate data is the foundation of safe and reliable design. One of the most valuable sources of this data is the Undisturbed Sample (UDS)—a soil sample taken with minimal disturbance, preserving its natural structure, water content, and mechanical properties.
When combined with powerful numerical modeling tools such as PLAXIS, Geo5, and MIDAS GTS, UDS provides engineers with high-quality input parameters to simulate soil behavior, predict deformation, and ensure the stability of engineering structures.
What is an Undisturbed Sample (UDS)?
An Undisturbed Sample (UDS) is a soil sample carefully collected to maintain its in-situ conditions. Unlike disturbed samples, UDS retains the soil’s original grain arrangement, pore structure, and natural moisture content.
Typical methods of obtaining UDS include the use of Shelby tubes, piston samplers, or ring samplers, as guided by international standards such as ASTM D1587.
Why UDS Matters in Numerical Modeling
Numerical modeling software like PLAXIS, Geo5, and MIDAS GTS relies heavily on accurate soil parameters. Using UDS ensures that the input data reflects real ground conditions, making simulations more reliable.
Key benefits of using UDS in numerical modeling include:
Accurate Strength Parameters → Cohesion (c), friction angle (φ), and modulus of elasticity (E).
Precise Consolidation Properties → Compression index (Cc), coefficient of consolidation (Cv).
Reliable Settlement Predictions → Long-term deformation analysis under applied loads.
Better Risk Assessment → Improved stability analysis for slopes, foundations, and retaining walls.
Application of UDS Data in Software
UDS in PLAXIS
PLAXIS is widely used for finite element analysis of geotechnical problems. UDS data provides reliable soil parameters for:
Settlement analysis of soft clay foundations
Slope stability assessment
Embankment and excavation modeling
Ground-structure interaction simulations
UDS in Geo5
Geo5 specializes in geotechnical design, particularly for retaining structures, slope stability, and foundations. With UDS input, engineers can:
Perform realistic deformation analysis
Model deep excavations and retaining walls
Evaluate long-term settlement and consolidation
UDS in MIDAS GTS
MIDAS GTS offers advanced 3D geotechnical modeling. UDS improves accuracy in:
Tunnel excavation simulation
Large-scale infrastructure projects
Complex soil-structure interactions
Predicting groundwater-soil responses
Case Example
Imagine designing a deep excavation in soft clay soil. If engineers rely only on SPT or CPT data, settlement predictions may be underestimated. By integrating UDS data into PLAXIS, the numerical model reflects true soil stiffness and consolidation characteristics, providing a more realistic assessment of risks and settlement behavior.
Undisturbed Samples (UDS) are indispensable in geotechnical engineering, particularly when used in numerical modeling software such as PLAXIS, Geo5, and MIDAS GTS. By preserving natural soil conditions, UDS ensures that simulations are reliable, risk assessments are accurate, and structural designs are safe.
If your project requires advanced geotechnical analysis, relying on high-quality UDS data will significantly improve the outcomes.