Determination of c and φ from IDT and Unconfined Compression Testing and Numerical Analysis

This paper presents an alternative criterion (simplified method) to determine the cohesion (c) and internal angle of friction (phi) properties for two granular materials lightly stabilized with slag lime and general blend (GB) cement-fly ash using indirect diametral tensile (IDT) strength and unconfined compressive strength (UCS). The c and phi values of the stabilized materials obtained on the basis of this criterion were related to the IDT strength and UCS. The results suggest that the c and phi can be estimated using this criterion and the c can be accurately related to either the IDT strength or UCS for lightly cementitiously stabilized granular materials. However, the IDT strength is a better characteristic than the UCS to estimate the c. To validate the criterion, the c and phi obtained from the proposed criterion were input in the numerical analyses of IDT testing with Mohr-Coulomb failure criterion using FLAC2D finite difference software. The predicted tensile stress-horizontal diametrical deformation numerical results were compared with the corresponding experimental results. On the basis of this numerical analysis, the c and phi parameters estimated from this method could predict the experimental results well in the elastic region but over-predicted the ultimate stress. DOI: 10.1061/(ASCE)MT.1943-5533.0000493. (c) 2012 American Society of Civil Engineers.