Model Experiments on Failure of Sand Bed Beneath a Structure Subjected to Cyclic Loading and Its Countermeasure

Mechanical Behavior of Anisotropic Sand Ground Beneath Structures Subjected to Cyclic Loading Such as Wave Loading

“…Additionally, the excess pore water pressure is not remarkably accumulated. Such a tendency of the pore water pressure was also observed for other points in the ground, although they were omitted here (Kawamura et al, 1999a(Kawamura et al, , 1999b. As a result, it can be said that the seabed subjected to ocean wave loading progressively fails, which is induced not only by liquefaction but also by lateral-deformation with both sliding and tilting of coastal structures.…”

“…Figure 3(a) compares the stress condition in the seabed beneath structures subjected to wave-induced cyclic loading with that simulated in the model testing. The stress condition in prototype may be reproduced by appropriately combining vertical load (PVL, PVR), horizontal load (PHL, PHR) and oscillating water pressure sc based on the following relationship (Kawamura et al, 1999a(Kawamura et al, , 1999b;…”

“…In the previous study, countermeasures constructed by side walls beneath the structure and by sheet piles in the ground were proposed and were recognized to have a resistant eŠect on lateral deformation (Kawamura et al, 1999b). In consideration of the test results, the size of the side wall made of stainless steel was adopted as 50 mm in height (＝Lw), 3 mm in thickness (＝tw), and 580 mm in length.…”

“…A larger value between SVL and SVR/or SHL and SHR was deˆned as SVmajor/or SHmajor, respectively. Lateral deformation (dL, dR) in the ground was measured using 4 strands of spaghetti (diameter was 1.9 mm) vertically inserted at 25 mm intervals in the ground (Tani and Craig, 1995; Kawamura et al, 1999b). Soil volumes of deformation Vd and Vr were calculated according to the lateral deformation area of deformed spaghetti and the settlement area of the model structure, respectively ( see the shaded area in Fig.…”

“…In view of the above, an apparatus which is capable of simulating the various stress conditions produced by the oscillation of ocean wave force under two-dimensional plane strain condition was developed in previous studies (Miura et al, 1995;Kawamura et al, 1999aKawamura et al, , 1999b). …”