Numerical study on load-settlement relationships of shallow foundation under extremely low confining pressure

In order to investigate the ground behavior under shallow foundation with extremely low confining pressure, numerical analysis has been performed using the Material Point Method. Material Point Method is one of particle-based methods but it still uses numerical grid. It has been applied to many problems of geomaterial since it was proposed for the first time. The authors focus on the robustness of the method under large deformation problem and applied it to the shallow foundation problem of geomaterial. In this paper, the formulation and implementation of Material Point Method are described, followed by verification and validation for the implemented code. Then, the parametric investigations on ground behavior under shallow foundation have been carried out

Large deformation analysis of ground with wall movement or hallow foundation under extremely low confining pressure using PIV

Large-scale natural disasters have occurred frequently in recent years. In such disasters, large ground deformation has been a recurring phenomenon. As it directly affects the structure, has dureable design is necessitated to minimize the damages. Additionally, the fracture process zones are predicted using numerical analysis, and thereafter, the results of the analysis are validated after comparison with the experimental ones. In this study, image analysis is performed using particle image velocimetry (PIV), and subsequently, the analysis results are validated by the comparison. We herein aim to improve the precision of the image-analysis results, and examine the experimental or analytical condition of reproducing the deformation

DEM slope-failure analysis of the Minami-Aso / Tateno area during the 2016 Kumamoto earthquakes

The Kumamoto earthquakes, which occurred on April 16, 2016, included deep large-scale landslides in the Minami-Aso village / Tateno area; the Aso Bridge collapsed completely because of this slope failure. Aso Bridge is considered to have collapsed for various reasons, e.g., fault displacements, earthquake accelerations, and landslide sediment depositions on the bridge. In this study, the possibility of landslide-sediment depositions on the bridge was assessed as a reason for the bridge collapse using the discrete element method (DEM), and the landslides at Aso Bridge were reproduced. An experiment and analysis were conducted on the large deformation of aluminum-bar laminated ground with wall movement, to confirm the applicability of DEM to large ground-deformation problems. Next, the Aso Bridge slope-failure analysis was carried out, based on different analysis conditions, and the sediment distribution was compared with field observation results from qualitative and quantitative viewpoints. It was concluded that sediment deposition on the bridge was not a cause of the Aso Bridge failure

Latent heat in the chiral phase transition

The chiral phase transition at finite temperature and density is discussed in the framework of the QCD-like gauge field theory. The thermodynamical potential is investigated using a variational approach. Latent heat generated in the first-order phase transition is calculated. It is found that the latent heat is enhanced near the tricritical point and is more than several hundred MeV per quark.Comment: 6 pages, 3 figure

Flavor-Mixing Effects on the QCD Phase Diagram at non-vanishing Isospin Chemical Potential: One or Two Phase Transitions?

We investigate effects of a fixed nonzero isospin chemical potential on the mu_B-T phase diagram of strongly interacting matter using a Nambu--Jona-Lasinio-type four fermion interaction. We focus on the influence of a flavor-mixing interaction induced by instantons. We find that already for rather moderate values of the coupling strength in the flavor-mixing channel the recent findings of two seperate phase transitions do not persist.Comment: 7 pages, 2 ps figure

Current quark mass effects on chiral phase transition of QCD in the improved ladder approximation

Current quark mass effects on the chiral phase transition of QCD is studied in the improved ladder approximation. An infrared behavior of the gluon propagator is modified in terms of an effective running coupling. The analysis is based on a composite operator formalism and a variational approach. We use the Schwinger-Dyson equation to give a ``normalization condition'' for the Cornwall-Jackiw-Tomboulis effective potential and to isolate the ultraviolet divergence which appears in an expression for the quark-antiquark condensate. We study the current quark mass effects on the order parameter at zero temperature and density. We then calculate the effective potential at finite temperature and density and investigate the current quark mass effects on the chiral phase transition. We find a smooth crossover for $T>0$, $\mu=0$ and a first-order phase transition for $\mu>0$, T=0. Critical exponents are also studied and our model gives the classical mean-field values. We also study the temperature dependence of masses of scalar and pseudoscalar bosons. A critical end point in the $T$-$\mu$ plane is found at $T \sim 100$ MeV, $\mu \sim 300$ MeV.Comment: 19 pages, 13 figure