Earthquakes as a coupled shear stress-high pore pressure dynamical system

1996 ◽  
Vol 23 (2) ◽  
pp. 197-200 ◽  
Author(s):  
Stephen A. Miller ◽  
Amos Nur ◽  
David L. Olgaard
Keyword(s):  
Dynamical System ◽  
Shear Stress ◽  
Pore Pressure

scholarly journals Energy dissipation and liquefaction at Port Island, Kobe

1998 ◽  
Vol 31 (1) ◽  
pp. 33-50 ◽  
Author(s):  
R. O. Davis ◽  
J. B. Berrill
Keyword(s):  
Shear Stress ◽  
Energy Dissipation ◽  
Shear Strain ◽  
Pore Pressure ◽  
Calculation Method ◽  
Horizontal Plane ◽  
Dissipated Energy ◽  
Stress And Strain ◽  
Shear Stress And Strain ◽  
Reclaimed Soils

The Port Island, Kobe downhole records from the Hyogo-ken Nanbu earthquake are analysed to obtain approximate histories of shear stress, shear strain and dissipated energy at a range of depths. Our calculation method relies on measured accelerations in the horizontal plane to produce horizontal components of shear stress and strain using instantaneous modal superposition. A simple dissipated energy-dynamic pore pressure relationship is used to model the development of pore pressure leading to liquefaction. The results show a rapidly developing zone of liquefaction which initiates at a depth of roughly 15 metres in the Port Island reclaimed soils.

scholarly journals Waves on Glacier Beds

1989 ◽  
Vol 35 (120) ◽  
pp. 179-182 ◽  
Author(s):  
V.L. Mazo
Keyword(s):  
Dynamical System ◽  
Shear Stress ◽  
Incompressible Fluid ◽  
Spatial Scale ◽  
Viscous Incompressible Fluid ◽  
Spatial Scales ◽  
Longitudinal Profiles ◽  
Basal Shear

Abstract A joint dynamical system comprising both an eroding glacier and an eroded bed is considered to describe the formation of cirques and stepped longitudinal profiles of trough valleys. A glacier is modelled as a layer of a very viscous incompressible fluid flowing down an inclined bed. The rate of erosion is assumed to be determined by the basal shear stress. The dynamics of small longitudinal perturbations are studied. The analysis shows that the perturbations propagate up the glacier bed with velocities that are different for the perturbations of different spatial scales. As a result, a perturbation of a specific spatial scale stands out against the others and develops into the morphological forms considered here.

scholarly journals Characteristics of Bituminous Coal Permeability Response to the Pore Pressure and Effective Shear Stress in the Huaibei Coalfield in China

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Lei Zhang ◽  
Zhiwei Ye ◽  
Mengqian Huang ◽  
Cun Zhang
Keyword(s):  
Shear Stress ◽  
Pore Pressure ◽  
Coal Mine ◽  
Gas Flow ◽  
Bituminous Coal ◽  
Stress Conditions ◽  
Coal Permeability ◽  
Gas Seepage ◽  
Shear Slip ◽  
Huaibei Coalfield

The coal permeability is known to be influenced by the pore pressure and effective stress in coal mines. In this study, the characteristics of the bituminous coal permeability response to the pore pressure and effective shear stress in the Xutuan coal mine in Huaibei Coalfield in China were investigated under different stress conditions. For this purpose, gas seepage tests with various stress levels were conducted via the original gas flow and displacement testing apparatus using bituminous coal samples from the Xutuan coal mine. The pore pressure effect on the permeability under different stress conditions was assessed by varying the pore pressure in coal samples and simulating different in situ stresses. The axial and radial pressures were controlled to study the response of coal permeability to the effective shear stress. The experimental results revealed that with an increase in pore pressure, the permeability of coal in different stress environments firstly drops and then rises. The permeability increased gradually with the effective shear stress, which trend became more pronounced when the effective shear stress exceeded zero. In case of the axial pressure exceeding the radial one, the cross shear slip was observed, for which the permeability of coal samples increased with the effective shear stress. In the opposite case, the separated shear slip was observed, with the reverse trend.

Symbolic Calculations

2021 ◽  
pp. 277-310
Keyword(s):  
Dynamical System ◽  
Shear Stress ◽  
Laplace Transform ◽  
Symbolic Calculation ◽  
Lubrication Film ◽  
Algebraic Expressions ◽  
Mathematical Expressions ◽  
Symbolic Calculations ◽  
The Laplace Transform ◽  
Scale Shear

The chapter is devoted to symbolic calculations in which the variables and commands operate on mathematical expressions containing symbolic variables. The representation of a symbolic expression, its simplification, the solution of algebraic expressions, symbolic differentiation and integration, and conversion of the symbolic numbers to their decimal form are described. ODEs solutions are also presented. The final sections of the chapter give examples of the symbolic calculation implementation for some mechanical and tribological problems that were solved numerically in previous chapters, namely lengthening a two-spring scale, shear stress in a lubrication film, a centroid of a certain plate, and two-way solutions of the ODE describing the second order dynamical system – traditional and using the Laplace transform.

Explicit Model for Cumulative Pore Pressure of Saturated Soft Clay

2012 ◽  
Vol 256-259 ◽  
pp. 267-270 ◽  
Author(s):  
Zhao Ming Yao ◽  
Jun Hao Chen
Keyword(s):  
Shear Stress ◽  
Pore Pressure ◽  
Principal Stress ◽  
Axial Stress ◽  
Soft Clay ◽  
Explicit Model ◽  
Traffic Loading ◽  
Cyclic Shear ◽  
Stress Rotation ◽  
Axial Cyclic Loading

The principal stress axial would cyclic rotate when the moving pressure passed. In order to analyze long-term settlement of the ground subjected to traffic loading, the simplified method based on explicit model for predicting the accumulative deformations is usually preferred. The traditional model could not reflect the phenomenon of principal stress rotation. After the axial stress controlled equation and circumferential shear stress controlled equation were derived, A series of consolidated undrained cyclic shear tests were performed under the condition that the general shear stress value was constant and the principal stress angle was rotating. The explicit pore pressure model reference was verified to calculate the accumulative pore pressure caused by the principal stress axial cyclic loading.

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