Abstract:Based on the theoretical framework of quantitative description for void fabric with the principle of stereology, the void fabric tensor redefined with normalized idea, and a novel description method of void fabric for sand was proposed. The porosity amplitude parameter defined by the second invariant of the plane tensor to describe the degree of anisotropy and the direction parameter defined by its component to describe its direction, the plane distribution of void fabric were described by these two scalars. The program with different image processing techniques that eliminate the confounding factors of analysis on scanning electron microscope(SEM) image of sand samples was developed to obtain a clear binary image with optimization methods. The SEM image analysis of sand sample showed that parallel test lines with different angles could measure the average porosity but could not measure the porosity distribution, while the circular test line could measure the plane distribution of void fabric. The new method with two scalar described the pore distribution on the plane, with the changed of pore geometry relationship, which degraded to the existing description format naturally. Image analysis validated the rationality of the new method.

Abstract:Abstract: Geological characters of dredger fill have been studied in recent years and the engineering geological properties of dredger fill is comprehensively affected by the material composition and microstructure. Because there’re many difficult factors such as sampling and sample preparation, microstructure is indispensable but seldom involved in the former research. Taking the dredger fill in Tianjin Binhai New Area as study object, the mineral composition is identified by X-ray diffraction approach, and the microstructure is studied by scanning electronic microscope (SEM), along with quantificational analysis of the microstructure using WD-5 picture processing system. And then the changing of evaluation indicators in two different reinforcement approaches, such as the size of structure element and pore, abundance, and directional frequency are discussed. The conclusion indicates that after water drainage treatment, the porosity becomes smaller, the dispersed structural elements of soil become agglomerated elements, displaying a variety of oblate. Simultaneously, the pores in the soil are diminished and lose balance, and directing property becomes indistinct. Consolidation degree of soil becomes higher.

Abstract:The Radial Tidal Sandy Ridge System (RTSRS) in the south Yellow Sea has very complex submarine topography. It is fundmental and vital for the scientific research, coastal planning and exploitation to have subtle digital terrain model, 3-dimention visual model and statistics of the different topographic units. The bathymetric survey data were recently collected in the north RTSRS using single-beam echo sounding technique. Kriging interpolation method is considered as the best choice to generate the digital terrain model for the current bathymetric data according to the residual analysis on the measured and interpolated value. The RTSRS can be visually subdivided into four topographic sub-units, including shoal, ridge, channel and broad valley through using the water-depth color bar. The microtopography of ridges and channels can be visually displayed by the profile curvature, like the sub-scale channels on the ridges and the sub-scale ridges in the channels, and quantitatively calculated in area and their percentage of the totall. Quantitatvie analyses on the slope of the ridges and channels shows the RTSRS is dominated by the horizontal-to-weakly-inclined topography with slope angle less than 5°, which accounts for 60% of the total in area and is mainly distributed on the broad valleys, the top of the ridges and at the middle of the channels. The topographic plan curvature and tangential curvature bear some information of marine hydrodynamics, in that the inner shallow region with strong currents tends to have negative value, and the outer deep region with weak currents has positive value of the tow parameters.