複合体の弾性理論による花崗岩の空隙形状分布の推定
1986 年 102 巻 1183 号 p. 553-559
詳細
1986 年 102 巻 1183 号 p. 553-559
Based on Kuster's expression for the elastic moduli of composite materials, the pore aspect ratio spectrum of granite is estimated.
The three conditions given below are assumed to generate 3640 types of pore aspect ratio spectra.
1) Aspect ratio (α) ranges from 100 to 10-5 and the distribution of the value of α is expressed with discrete line spectrum.El even values of aspect ratio are used to divide in equally spaced intervals a logarithmic scale.
2) The distribution of aspect ratio has the normal distribution.
3) A spectrum of pore shapes has a unique maximum.
The longitudinal wave velocities are calculated for 3640 models with the limitations mentioned above, and the pore aspect ratio spectra of granite are investigated by fitting the calculated velocities of rocks in dry and saturated states to the laboratory data.
The results show that the variation of longitudinal wave velocity with respect to water content can be quantitatively illustrated by the use of a pore model with mixeci asnect ratios instead of a single aspect ratio model, and that the most suitable model explaining velocity increase due to water saturation is that containing pores ranging from sphere to cracks (aspect ratio 100 to 10-5). Compared with the data of crstalline limestone, the relative amount of very thin cracks (aspect ratio<10-3) contained in granite is less than that of crystalline limestone.
