Typical test on dry transparent soil – test 2 with phreatic surface at d_w = 80 mm – time series of images with particle image velocimetry (PIV) vectors showing failure mechanism consistent with Prandtl style assumed in conventional bearing capacity analysis: (a) 0·00 s; (b) 0·02 s; (c) 0·04 s; (d) 0·06 s; (e) 0·08 s; (f) 0·10 s; (g) 0·12 s; (h) 0·14 s