Prediction of the Coefficient of Volume Compressibility of Fine-Grained Soils Using a Modified Shrinkage Factor and SPT Data
摘要
The coefficient of volume compressibility (mv) is a crucial parameter in geotechnical engineering analyses, such as settlement calculations and time-dependent settlement predictions. This parameter is typically determined through one-dimensional consolidation tests, which is quite elaborate and require undisturbed soil samples. Researchers have attempted to predict mv through field tests (especially penetration resistance obtained from Standard Penetration Test, SPT N-value) and with simple index properties. However, a careful examination of current literature reveals shortcomings in these correlations, underscoring the necessity for a simple method for predicting mv. In this direction, an effort is made to address the limitations and also extend the correlation proposed by Stroud (in: Proceedings of the European symposium on penetration testing, Stockholm, 1974) to predict mv, which was applicable for a pressure increment of 100 kN/m2 in excess of existing overburden pressure, by introducing two key factors: the modified shrinkage factor in place of plasticity index to account for the soil type and the modified factor accounting for the initial pressure from where incremental pressure is evaluated, as a representative of the soil state. The method discussed in this paper demonstrates a good nonlinear relationship with a correlation coefficient of 0.89 between the modified shrinkage factor and the modified factor, providing an effective approach for predicting mv. The proposed model not only simplifies the process, but also, significantly reduces the need for extensive laboratory testing, making it a valuable tool for researchers and practitioners alike. Additionally, utilizing the proposed model, a procedure has been developed to trace the void ratio-log σv′ curve (e-log σv′) for the loading case.