The weak understanding of crack growth mechanisms in ductile soil is addressed by testing a new fracture mechanics approach. Samples are fractured using a deep-notch (3-point) bend test, with data on sample bending, crack growth, and crack mouth opening collected to assess the crack opening angle (COA), the crack tip opening angle (CTOA), and plastic energy dissipation rate (D-pt). The test variables are clay and salinity content, with samples formed from mixtures of kaolinite and fine sand. The CTOA and D-pl detect differences in fracture mechanics due to clay, but not salinity. The energy needed to drive crack extension, D-pl, is one order of magnitude higher for samples containing a ratio of sand to kaolinite of 75:25, as compared with 50:50. However, the CTOA due to plasticity was 0.19 and 0.24 for the same samples respectively, indicating that more strain is needed for crack growth in the specimens with more clay.
|Number of pages||6|
|Journal||Soil Science Society of America Journal|
|Publication status||Published - 2001|
- UNSATURATED SOILS
- ENERGY-DISSIPATION RATE