We model landslide initiation as slip surface growth driven by local elevated pore pressure, with particular reference to submarine slides. Assuming an elastic medium and friction that weakens with slip, solutions exist in which the slip surface may dynamically grow, without further pore pressure increases, at a rate of the order of the sediment shear wave speed, a situation comparable to earth...

[1] Pore pressure changes are rigorously included in Coulomb stress calculations for fault interaction studies. These are considered changes under undrained conditions for analyzing very short term postseismic response. The assumption that pore pressure is proportional to faultnormal stress leads to the widely used concept of an effective friction coefficient. We provide an exact expression for...

The classical Lusternik-Schnirelman-Borsuk theorem states that if a d-sphere is covered by d + 1 closed sets, then at least one of the sets must contain a pair of antipodal points. In this paper, we prove a combinatorial version of this theorem for hypercubes. It is not hard to show that for any cover of the facets of a d-cube by d sets of facets, at least one such set contains a pair of antipo...

Shallit and Wang studied deterministic automatic complexity of words. They showed that the automatic Hausdorff dimension I(t) of the infinite Thue word satisfies 1/3 ≤ I(t) ≤ 2/3. We improve that result by showing that I(t) ≥ 1/2. For nondeterministic automatic complexity we show I(t) = 1/2. We prove that such complexity AN of a word x of length n satisfies AN (x) ≤ b(n) := bn/2c+ 1. This enabl...

[1] Recent, detailed examinations of fault zones show that walls of faults are often bordered by materials that are different from each other and from the more uniform material farther away. In addition, they show that the ultracataclastic core of mature fault zones, where slip is concentrated, is less permeable to flow across it than the adjoining material of the damage zone. Inhomogeneous sli...

In this paper, we find that with the decrease in the average pore pressure in the process of gas production, both the slippage effect and the stress sensitivity effect will gradually increase; the increase in the slippage effect is significant, while the increase in the stress sensitivity effect is not. In this paper, the Kalamay volcanic gas reservoir of the Junggar Basin in China was selected...

Solids of different shapes resonate according to their peculiar geometry. Although physics, for some fundamental shapes such as the cube and the sphere, provides explicit formulas for determining the modal frequencies, a general resonance analysis of 3-D shapes must be conducted using numerical methods. In this paper, Waveguide Meshes are used to model intermediate geometries between the cube a...

Computational pore-scale network models describe two-phase porous media ̄ow systems by resolving individual interfaces at the pore scale, and tracking these interfaces through the pore network. Coupled with volume averaging techniques, these models can reproduce relationships between measured variables like capillary pressure, saturation, and relative permeability. In addition, these models all...

Accurate pore pressure prediction is a necessary requirement to well structure optimizing, drilling difficulty minimizing, drilling accidents preventing. It plays a very important role in the economically and efficiently well operating. Previous methods for pore prediction have their own hypothesizes and cannot take into consideration factors that indicate or influence the pore pressure, so the...