This paper gives an overall discussion about water level change on slopes under wave action, including wave runup, wave rundown and wave up-down amplitude, and a suggested formula for their calculation.
The purpose of the research was to investigate two-dimensional modeling of efficiency of mixing, resulting from the reflection of a linear internal wave field (IWF) off a continental slope. Efficiency of deep ocean mi...The purpose of the research was to investigate two-dimensional modeling of efficiency of mixing, resulting from the reflection of a linear internal wave field (IWF) off a continental slope. Efficiency of deep ocean mixing was associated with the energy balance of the radiating IWF into an interior of the ocean in the vicinity of a sloping bottom topography. Since waves are generated not only at the fundamental frequency but also at all of its harmonics <em>ω</em><sub><em>n</em></sub> = <em>nω</em> less than buoyancy frequency <i>N</i> and greater than Coriolis frequency <i>f</i>, our analysis includes, in general, an infinite number of discrete internal wave modes <i>n</i> satisfying the dispersion relationship for internal waves. However, since we are interested only in the radiating part of the field, the mode numbers are limited. Due to multiple singularities of order two caused by resonance in the vicinity of critical slope, the energy is visualized in <em>L</em><sub><em>δ</em></sub> -norm with <em>δ</em> > 2. Research results include the visualization of the effects of the continental slope and the Earth’s rotation on resulting energy in the vicinity of the slope.展开更多
In accordance with the principle of similarity in geology and topography,the V3S0(the average shear-velocity down to a 30m depth below the surface) approximation of sites is acquired by correlation between V3S0 and sl...In accordance with the principle of similarity in geology and topography,the V3S0(the average shear-velocity down to a 30m depth below the surface) approximation of sites is acquired by correlation between V3S0 and slopes after calculating the maximum slope of topography using the 30-sec Chinese Mainland DEM(Digital Elevation Model) data set.Site-amplification factors are then quantified with V3S0 and applied to the ShakeMap system developed by this study to revise ground-motion amplitudes on bedrock estimated from empirical relationships.Finally,the distribution of ground motion parameters on the surface is obtained.This article also introduces the calculation process,calculation models of the ShakeMap systems and related software systems.In conclusion,certain examples indicate that the ShakeMap system is feasible in the Chinese Mainland.展开更多
Trapping of oblique surface gravity waves by dual porous barriers near a wall is studied in the presence of step type varying bottom bed that is connected on both sides by water of uniform depths. The porous barriers ...Trapping of oblique surface gravity waves by dual porous barriers near a wall is studied in the presence of step type varying bottom bed that is connected on both sides by water of uniform depths. The porous barriers are assumed to be fixed at a certain distance in front of a vertical rigid wall. Using linear water wave theory and Darcy's law for flow past porous structure, the physical problem is converted into a boundary value problem. Using eigenfunction expansion in the uniform bottom bed region and modified mild-slope equation in the varying bottom bed region, the mathematical problem is handled for solution. Moreover, certain jump conditions are used to account for mass conservation at slope discontinuities in the bottom bed profile. To understand the effect of dual porous barriers in creating tranquility zone and minimum load on the sea wall, reflection coefficient, wave forces acting on the barrier and the wall, and surface wave elevation are computed and analyzed for different values of depth ratio, porous-effect parameter, incident wave angle, gap between the barriers and wall and slope length of undulated bottom. The study reveals that with moderate porosity and suitable gap between barriers and sea wall, using dual barriers an effective wave trapping system can be developed which will exert less wave force on the barriers and the rigid wall. The proposed wave trapping system is likely to be of immense help for protecting various facilities/infrastructures in coastal environment.展开更多
文摘This paper gives an overall discussion about water level change on slopes under wave action, including wave runup, wave rundown and wave up-down amplitude, and a suggested formula for their calculation.
文摘The purpose of the research was to investigate two-dimensional modeling of efficiency of mixing, resulting from the reflection of a linear internal wave field (IWF) off a continental slope. Efficiency of deep ocean mixing was associated with the energy balance of the radiating IWF into an interior of the ocean in the vicinity of a sloping bottom topography. Since waves are generated not only at the fundamental frequency but also at all of its harmonics <em>ω</em><sub><em>n</em></sub> = <em>nω</em> less than buoyancy frequency <i>N</i> and greater than Coriolis frequency <i>f</i>, our analysis includes, in general, an infinite number of discrete internal wave modes <i>n</i> satisfying the dispersion relationship for internal waves. However, since we are interested only in the radiating part of the field, the mode numbers are limited. Due to multiple singularities of order two caused by resonance in the vicinity of critical slope, the energy is visualized in <em>L</em><sub><em>δ</em></sub> -norm with <em>δ</em> > 2. Research results include the visualization of the effects of the continental slope and the Earth’s rotation on resulting energy in the vicinity of the slope.
基金sponsored by the Basic Scientific Research Business Special,Institute of Geophysics,China Earthquake Administration (BQJB08B24)
文摘In accordance with the principle of similarity in geology and topography,the V3S0(the average shear-velocity down to a 30m depth below the surface) approximation of sites is acquired by correlation between V3S0 and slopes after calculating the maximum slope of topography using the 30-sec Chinese Mainland DEM(Digital Elevation Model) data set.Site-amplification factors are then quantified with V3S0 and applied to the ShakeMap system developed by this study to revise ground-motion amplitudes on bedrock estimated from empirical relationships.Finally,the distribution of ground motion parameters on the surface is obtained.This article also introduces the calculation process,calculation models of the ShakeMap systems and related software systems.In conclusion,certain examples indicate that the ShakeMap system is feasible in the Chinese Mainland.
文摘Trapping of oblique surface gravity waves by dual porous barriers near a wall is studied in the presence of step type varying bottom bed that is connected on both sides by water of uniform depths. The porous barriers are assumed to be fixed at a certain distance in front of a vertical rigid wall. Using linear water wave theory and Darcy's law for flow past porous structure, the physical problem is converted into a boundary value problem. Using eigenfunction expansion in the uniform bottom bed region and modified mild-slope equation in the varying bottom bed region, the mathematical problem is handled for solution. Moreover, certain jump conditions are used to account for mass conservation at slope discontinuities in the bottom bed profile. To understand the effect of dual porous barriers in creating tranquility zone and minimum load on the sea wall, reflection coefficient, wave forces acting on the barrier and the wall, and surface wave elevation are computed and analyzed for different values of depth ratio, porous-effect parameter, incident wave angle, gap between the barriers and wall and slope length of undulated bottom. The study reveals that with moderate porosity and suitable gap between barriers and sea wall, using dual barriers an effective wave trapping system can be developed which will exert less wave force on the barriers and the rigid wall. The proposed wave trapping system is likely to be of immense help for protecting various facilities/infrastructures in coastal environment.
