On the influence of progressive failure on the bearing capacity of shallow foundations in dense sand

Centrifuge tests on strip footings on sand with a weak layer

“…The preceding hypotheses do not permit the prediction of the behaviour of the soil-footing system beyond the peak bearing pressure (Potts andZdravkovic, 1999, 2001). Weak layer: CM3 talc powder Kumar and Kouzer (2007) Vesić (1973) Terzaghi (1943) Present research Brinch Hansen (1970) This research (D r = 95%) Kimura et al (1985) Toyoura sand (D r = 89-97%) Yamaguchi et al (1976) Toyoura sand Figure 19) closely resembles Prandtl's (1920) except for the angle of emersion at ground surface that nearly equals 45°−y 0 1p /2 (instead of 45°− f 0 1p /2). The small instability of numerical results in the pre-peak phase is due to the non-associativity of the constitutive model (Frydman and Burd, 1997).…”

“…Muhs (1965), Yamaguchi et al (1976), Kimura et al (1985), Tatsuoka et al (1991), Kusakabe (1992), Aiban and Znidarčić (1995), Tatsuoka (2001), McMahon and Bolton (2011)). It is worth mentioning that Yamaguchi et al (1976) discovered nonsymmetry in centrifuge models at 40g (B m = 20, 30 and 40 mm, B p = 0·80, 1·2 and 1·60) using radiography, while Kimura et al (1985) demonstrated, also by means of X-ray techniques, that at 20g (B m = 30 mm, B p = 0·6 m) that the slip lines are not symmetric when the base of the footing is rough, while for smooth bases the slip lines are very nearly symmetric.…”

“…Valore et al (2017) for 1g tests). In Figure 16(a), the trend of the 'equivalent ultimate bearing capacity factor' N Ã g = 2q lim /(gB p ) is plotted against the prototype width, B p , while in Figure 16(b), the experimental results relative to footing on homogeneous sand were compared with other experimental data (Kimura et al, 1985;Yamaguchi et al, 1976) and with some theoretical solution (Brinch Hansen, 1970;Kumar and Kouzer, 2007;Terzaghi, 1943;Vesić, 1973). In Figure 17, the ultimate bearing pressure, q lim , is plotted against B p .…”

Model ground anchors under gravitational and centrifugal accelerations

“…Mikasa and Takada (1973) have performed centrifugal model tests on both shallow and deep foundations under compressive loads and have presented visual evidence of the difference in failure mode of the same model between tests at unit gravity and others at 60 g. Krebs Ovesen (1975) has summarised the findings of his own centrifuge expe riments along with those of Mikasa and Takada and of Cherkasov et al (1970) and has shown that the variation in model failure loads associated with the different modes of failure at different accelerations is consistent with substantial reductions in 0 with stress level increases. The results of centrifuge tests by Yamaguchi et al (1976) on surface and shallow foundations show similar effects.…”

Foundations

“…4) The ultimate capacity of circular footing (Kusakabe et al, 1986;Tani and Craig, 1995 The size dependency of the bearing capacity factor Ng has been an issue and is now considered to be caused by 1) stress dependency of internal friction angle, 2) progressive failure along slip lines and 3) particle size relative to a footing dimension, and perhaps even a combination of these factors. Centrifugal test results showed clear progressive failure (Yamaguchi et al, 1976) and suggested the dependency of internal friction angle (e.g., Hettler and Gudehus, 1988). However, Siddiquee et al (2001) claimed that particle size relative to a footing width plays a signiˆcant role on the size dependency.…”