A Study of the Anisotropy of Improved Clay Using the Nordic Dry Deep Mixing Method

This paper presents triaxial compression, extension and tension tests to investigate the undrained strength anisotropy of lime-cement improved clays. The tests were performed on both laboratory-prepared specimens and field samples from in situ dry deep mixed columns. Effective stress paths indicate isotropic drained failure envelopes with relatively high friction angles (~45–55°) and low cohesive intercepts. However, the undrained strength clearly shows strength anisotropy, with a ratio of strength in triaxial extension and tension to compression on average ~0.81 and ~0.67 for the laboratory specimens and field samples, respectively. The results are consistent with previous studies on similar type of improved clays. Further, negligible differences were observed between triaxial extension and tensions tests.