著者
狐崎 長琅
出版者
社団法人 物理探査学会
雑誌
物理探査 (ISSN:09127984)
巻号頁・発行日
vol.58, no.6, pp.631-642, 2005 (Released:2007-11-02)
参考文献数
14
被引用文献数
4 4

Elastic coefficients in the Biot theory (Biot coefficients) for fluid-saturated porous media are expressed by conventional elastic coefficients and porosity. Practical applicability of this theory is established by it. Derivation of Biot coefficients is generally performed by the deformation analysis in which the total stress is resolved into two components: the effective stress and the fluid (hydrostatic) stress. Use of this pair of stress components has been developed as powerful tools in soil mechanics, where soils are assumed to be the granular media whose solid parts consist of grains with point-contact. It is a problem to be considered whether the same premise underlies the expressions of Biot coefficients or not. In this point of view, we discuss the concept of this pair of stress components, and we remark that it is used in two different aspects as follows: The first aspect is evaluation of the shear resistance resulting from solid friction. In this case the effective stress is regarded as the key factor controlling the solid friction. The second aspect is utility for the deformation analysis. By converting the total stress into the above pair of components we can evaluate dilatation of the solid material and the skeleton separately. The first aspect needs the premise of granular media, but the second aspect is free from such restriction. The utility in the second aspect is demonstrated by actual evaluation of Biot coefficients. In this evaluation, we particularly assume propagation of the longitudinal plane wave as the situation of stress field. This situation is directly connected to geophysical application. Expressions of Biot coefficients as the result agree with those derived by other authors based on the situation of hydrostatic compression.
著者
狐崎 長琅 後藤 典俊 小林 芳正 井川 猛 堀家 正則 斉藤 徳美 黒田 徹 山根 一修 奥住 宏一
出版者
日本自然災害学会
雑誌
自然災害科学 (ISSN:02866021)
巻号頁・発行日
vol.9, no.3, pp.1-17, 1990-12-31
被引用文献数
45 75

The following two kinds of empirical relations are derived : 1) relations between the P-wave velocities and geological factors (facies, time, and depth), based on oil well data in Akita prefecture; 2) relations between the S-wave velocities and the P-wave ones, based on published and new data from in situ velocities measurements in relatively deep boreholes in Japan. Combination of the above two relations provides means for estimating the S-wave velocities from geological factors. A VSP experiment was carried out in a well of 1.3 km depth in Akita prefecture to provide this study with S- and P-wave data of oil field area. To demonstrate the purpose of this study, calculations of ground vibrations due to the vertically incident SH-waves are conducted for a two-dimentional seismic structure model corresponding to a typical sedimentary basin in Akita prefecture.