Response of a vertical strain seismometer to body waves

1966 ◽  
Vol 56 (4) ◽  
pp. 785-791
Author(s):  
Indra N. Gupta
Keyword(s):  
Finite Length ◽  
Finite Depth ◽  
Vertical Displacement ◽  
Infinite Medium ◽  
Body Waves ◽  
Poisson's Ratio ◽  
Angle Of Incidence ◽  
Arbitrary Angle ◽  
Vertical Strain ◽  
Phase Relationships

abstract Expressions have been derived for vertical strain due to P and SV type waves arriving at an arbitrary angle of incidence within a semi-infinite medium. The amplitude and phase relationships between vertical strain and vertical displacement have been investigated for both wave types, assuming a Poisson's ratio of 0.25. The effect of finite depth and finite length of the vertical strain instrument has been examined and found to be significant especially for small angles of incidence.

The Gliding of a Plate on a Stream of Finite Depth. Part II

1936 ◽  
Vol 32 (1) ◽  
pp. 67-85 ◽  
Author(s):  
A. E. Green
Keyword(s):  
Finite Length ◽  
Finite Depth ◽  
Numerical Calculations ◽  
Angle Of Incidence ◽  
Trailing Edge ◽  
Maximum Value ◽  
Flow Past

7. We have discussed the gliding of a plate of finite length on a stream of finite depth. Numerical calculations have been made for the case when the angle of incidence of the plate to the stream was 30°, the results for any other angle being similar.It was found that, for a given depth of stream and a given height of the trailing edge above the bed of the stream, the value of the lift increases with the length of the plate, until finally, when the plate is infinitely long, the lift assumes a maximum value. Further, for a given depth of stream, the total normal lift on the plate is independent of its height above the bed of the stream, when the length of the plate is small, except when the trailing edge of the plate is above the surface of the stream. Finally, when the depth of the stream is very large and the plate is near the middle of the stream, then our solution approximates to the classical Rayleigh flow past a plate in an infinite fluid.

COMPUTER RAY TRACING THROUGH COMPLEX GEOLOGICAL MODELS FOR GROUND MOTION STUDIES

Geophysics ◽  
1970 ◽  
Vol 35 (4) ◽  
pp. 586-602 ◽  
Author(s):  
Nazieh K. Yacoub ◽  
James H. Scott ◽  
F. A. McKeown
Keyword(s):  
Ray Tracing ◽  
Vertical Displacement ◽  
Test Site ◽  
Drill Hole ◽  
Body Waves ◽  
Angle Of Incidence ◽  
Nevada Test Site ◽  
Subsurface Geology ◽  
Geological Models ◽  
Motion Studies

A computer program has been developed to study the effect of subsurface geology on the propagation of seismic body waves. The program, which is based on ray theory and on numerical solution of Zoeppritz’s equations for any angle of incidence at elastic boundaries, traces seismic rays and energy distribution through geological models of any complexity. The geological models are composed of rock units that are assumed to be isotropic, perfectly elastic, and homogeneous, and are two‐dimensional in distribution. The ray tracing program was applied to two geologic models of the crust, that are more than 100 miles long, starting at drill hole UE20F in the Nevada Test Site. The results, displayed as raypath plots and plots of the amplitude of vertical displacement at the earth’s surface, graphically illustrate the strong influence of the spatial distribution and elastic property variations of rock units in raypath distribution.

scholarly journals Theoretical Studies of Convectively Forced Mesoscale Flows in Three Dimensions. Part II: Shear Flow with a Critical Level

2010 ◽  
Vol 67 (3) ◽  
pp. 694-712 ◽  
Author(s):  
Ji-Young Han ◽  
Jong-Jin Baik
Keyword(s):  
Shear Flow ◽  
Gravity Waves ◽  
Wind Direction ◽  
Critical Level ◽  
Deep Convection ◽  
Vertical Wind Shear ◽  
Finite Depth ◽  
Vertical Displacement ◽  
Two Dimensions ◽  
Three Dimensions

Abstract Convectively forced mesoscale flows in a shear flow with a critical level are theoretically investigated by obtaining analytic solutions for a hydrostatic, nonrotating, inviscid, Boussinesq airflow system. The response to surface pulse heating shows that near the center of the moving mode, the magnitude of the vertical velocity becomes constant after some time, whereas the magnitudes of the vertical displacement and perturbation horizontal velocity increase linearly with time. It is confirmed from the solutions obtained in present and previous studies that this result is valid regardless of the basic-state wind profile and dimension. The response to 3D finite-depth steady heating representing latent heating due to cumulus convection shows that, unlike in two dimensions, a low-level updraft that is necessary to sustain deep convection always occurs at the heating center regardless of the intensity of vertical wind shear and the heating depth. For deep heating across a critical level, little change occurs in the perturbation field below the critical level, although the heating top height increases. This is because downward-propagating gravity waves induced by the heating above, but not near, the critical level can hardly affect the flow response field below the critical level. When the basic-state wind backs with height, the vertex of V-shaped perturbations above the heating top points to a direction rotated a little clockwise from the basic-state wind direction. This is because the V-shaped perturbations above the heating top is induced by upward-propagating gravity waves that have passed through the layer below where the basic-state wind direction is clockwise relative to that above.

Settlement of a strip footing on a confined clay layer

1983 ◽  
Vol 20 (3) ◽  
pp. 535-542
Author(s):  
Brian B. Taylor ◽  
Elmer L. Matyas
Keyword(s):  
Stress Distribution ◽  
Plane Strain ◽  
Poisson’S Ratio ◽  
Ground Surface ◽  
Finite Depth ◽  
Strip Footing ◽  
Poisson's Ratio ◽  
Clay Layer ◽  
Line Load ◽  
Settlement Analysis

A procedure is described that permits an estimation of either consolidation or immediate settlements of a uniformly loaded, flexible strip footing founded below the ground surface. The soil above the base of the footing is sand, and the soil below the base consists of clay, which extends to a finite depth. The procedure is based on a solution of Kelvin's equations for a line load acting within an infinite solid. Charts are presented which permit an estimate of settlement for various compression moduli, Poisson's ratio, and clay thickness.The proposed method predicts consolidation settlements that are generally slightly greater than those predicted from Boussinesq theory. Consolidation settlements increase as Poisson's ratio increases. Immediate settlements are slightly greater than those reported previously. Keywords: consolidation, elasticity, footings, plane strain, settlement analysis, stress distribution.

Boundary Effects in Wake Flow

1968 ◽  
Vol 35 (3) ◽  
pp. 571-578
Author(s):  
C. Y. Liu
Keyword(s):  
Experimental Data ◽  
Flat Plate ◽  
Analytical Solutions ◽  
Angle Of Attack ◽  
Finite Depth ◽  
Wake Flow ◽  
Boundary Effects ◽  
Arbitrary Angle ◽  
Linearized Theory

Analytical solutions are obtained for the problem of boundary effects on the fully developed wake (or cavity) behind an inclined flat plate at an arbitrary angle of attack. The investigation is based on the Helmholtz free-streamline theory. Results are applied to four cases: (a) Blockage in a fixed-wall tunnel, (b) planing on a stream of finite depth, (c) planing toward a waterfall, and (d) flow over a flat plate in a bounded jet. Comparisons with linearized theory and available experimental data are made.

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