The Undrained Shear Strength of Overconsolidated Clays

The paper presents results of laboratory unconfined and confined shear tests. Tests were conducted on samples of clays taken from depth 100-300 meters below ground level. All confined tests were performed in triaxial apparatus following TXCIU procedure. Selected samples were tested in overconsolidation state. The OCR ratio values ranged from 3 to 28. Values of uniaxial compressive strength qu and undrained shear strength cu were established for each OCR ratio. The normalization procedure was done and the normalized ratio cu/σ’vc and qu/σ’vc were obtained. The results were compared with SHANSEP equation. The analysis shows that SHANSEP equation can be used for natural clayey soils in heavily overconsolidated state.