| Soil type | Global standard (theory) | Local practice factor (if no load test) | GEOSS recommendation | |-----------|--------------------------|------------------------------------------|----------------------| | Silty clay (stiff) | 60–100 kPa | 0.7 (local over-excavation common) | Use 50 kPa unless tested | | Loose sand | 30–50 kPa | 0.6 (vibration loosens during boring) | Use 25 kPa | | Weathered shale | 150–200 kPa | 1.0 (if cleaned base) | Test mandatory |
To ensure the integrity of the foundation, GeoSS and local authorities mandate specific site practices: | Soil type | Global standard (theory) |
) values. GeoSS provides empirical correlations based on decades of localized Standard Penetration Tests (SPT) and Cone Penetration Tests (CPT) to prevent the overestimation of pile capacities in soft soil layers. 2. Ultimate and Serviceability Limit States (ULS & SLS) Ultimate and Serviceability Limit States (ULS & SLS)
For high-capacity pile groups or piled-raft networks, borehole spacing must strictly stay within a in higher-risk zones. Testing must continue deep enough into competent bedrock to verify that the stratum can support the loads without punctured failure or excessive long-term consolidation settlement. Phase 2: Geotechnical and Structural Pile Design | Soil type | Global standard (theory) |