From CPT to Foundation Design: How DAARWIN Digitises Offshore Geotechnical Workflows

In offshore geotechnical engineering, Cone Penetration Testing (CPT and CPTu) remains a cornerstone for evaluating subsoil conditions—particularly within soft, layered marine sediments where borehole sampling is often limited or logistically constrained. However, despite the wealth of information CPT offers, many geotechnical workflows remain inefficient—fragmented by manual data handling, inconsistent interpretation protocols, and delayed integration into the design phase.

DAARWIN addresses these challenges through a comprehensive, cloud-based environment that streamlines the ingestion, interpretation, and application of CPT data throughout the offshore foundation design process.

From Data Ingestion to Interpretation

CPT data acquired offshore is often delivered in a range of formats, including AGS, CSV, Excel, and PDF. Manually processing this data can be error-prone and time-consuming, particularly when normalising and validating large datasets.

DAARWIN introduces automation at the point of data ingestion. CPT and CPTu files are parsed and structured according to standardised geotechnical conventions. Parameters such as cone resistance (qt), sleeve friction (fs), and pore pressure (u2) are automatically normalised using project-specific criteria, ensuring compatibility with downstream analysis. Visualisation tools allow engineers to immediately assess the quality and continuity of the data against depth—enabling early-stage decisions on data reliability and completeness.

Enhancing Classification and Parameter Derivation

Once data is structured, DAARWIN supports the rigorous classification of soil behaviour types. By applying established frameworks—such as Robertson’s 2010 charts, or alternative methods like Eslami & Fellenius—the platform enables consistent identification of stratigraphy across the site.

This classification process is not limited to visual charts. DAARWIN computes derived geotechnical parameters including undrained shear strength (Su), effective friction angle (φ'), constrained modulus (M), and relative density, based on calibrated correlations. These parameters can be compared across CPT locations to assess lateral continuity of soil units—informing design zoning and foundation placement strategies.

Building a Cohesive Ground Model

CPT data, while powerful, offers a point-based view of the subsurface. DAARWIN enhances its utility by integrating these profiles with borehole logs, laboratory results, and geophysical surveys into a multi-source ground model.

Engineers can construct 2D cross-sections or 3D interpolated surfaces that visualise stratigraphy, soil behaviour zones, and key properties across the project footprint. These models are dynamic and exportable—serving as inputs for numerical analysis, pile group layout, or FE mesh generation. In complex offshore conditions, this capability strengthens geotechnical interpretation and improves collaboration with structural teams.

One particularly valuable addition to the model is the representation of the groundwater table. DAARWIN enables the incorporation of water table data either from CPTu dissipation tests, borehole records, or piezometric monitoring. This allows engineers to visualise the phreatic surface in relation to stratigraphy, helping to evaluate effective stress conditions, identify zones of potential excess pore pressure, and assess construction dewatering requirements. Representing the water table as part of the ground model provides vital context for both design assumptions and risk mitigation. DAARWIN supports both static and real-time integration of water table data, allowing users to update phreatic surface information as new field monitoring results become available.

Supporting Foundation Design Inputs

DAARWIN bridges the gap between investigation and design by translating interpreted data directly into foundation design parameters.

In addition, DAARWIN accommodates site-specific calibration workflows, such as developing cyclic degradation curves or adjusting undrained strengths for installation effects. This makes the transition from soil characterisation to foundation sizing more seamless, allowing geotechnical engineers to respond to real-world variability while maintaining analytical rigour.

Informing Design Sensitivity and Calibration

Acknowledging the inherent variability in offshore ground conditions, DAARWIN enables parametric analysis at early design stages. Engineers can assess how fluctuations in input parameters affect predicted outcomes such as axial capacity, settlement, or lateral response. Multiple CPT-based soil profiles can be run through design algorithms in batch mode, providing a probabilistic view of foundation performance.

These features not only support design optimisation but also underpin risk management strategies, allowing for contingency evaluation and more targeted site investigations.

Integrating Field Performance and Feedback

Geotechnical design does not end at installation. DAARWIN enables post-construction integration of monitoring data—such as pile driving logs, settlement records, and pore pressure measurements—back into the ground model. This allows for direct comparison of predicted versus observed performance.

Engineers can recalibrate design parameters based on actual field behaviour, refine models for future phases, and build a comprehensive, project-specific geotechnical knowledge base. By maintaining a continuous feedback loop, DAARWIN supports performance-based design and asset lifecycle management.