ABSTRACT
The authors are comparing failure-time prediction methods. The methods are based on Equation 1, as a function that can represent strain or displacement divergence phenomenon prior to failure. Inversevelocity (INV) method was proposed to predict failure-time of landslides, and rock failure (Fukuzono, 1985). The authors further investigated the two methods by Fukada et al. (1999) for prediction of geomechanical failure-time. The first method is based on non-linear approximation (NLA) of (du/dt)-t curve or (dε/dt)-t curve (Figure 1a), and the other method is based on the slope of t(du/dt)-du/dt curve or t(dε/dt)-dε/dt curve (SLO) as illustrated in Figure 1b. Failure-time of case histories, which includes rock mass failure, Asamushi and Vaiont landslides are predicted. Subsequently, the reliability of these methods is evaluated. With the same principles, predictions using circumferential strain εc on Shikotsu welded tuff (SWT) under uniaxial compression creep tests, and predictions of failure-time for Inada granite under Brazilian creep tests are presented. The general focus of this research is to attempt to predict failure-time of geo-hazards in the terminal phase of failure. It was realised that SLO is better than the INV method.
