In this research paper the residual strength of clay is deemed to correspond to the total value of the strength of the soil particles used in the specimen. The frictional force of the soil particles was measured by using Atomic Force Microscope (AFM); then the frictional force and the residual strength of the specimen were compared. The surface profile of the shear surface in residual state, the friction coefficient, the velocity dependency of frictional force and the adsorptive force of clay adsorbed water were measured by AFM in micro area. As a result, although the shear surface appeared flat to the naked eye, it actually turned out to be rough. The increase of the frictional force in micro area was proportional to the increase in the vertical stress, and the increase rate or angle of friction [φ] was very small: less than 5°. The adsorptive force of adsorbed water was 4.1×10^<-2>nN for Kunipia F, 8.9×10^<-1>nN for Kaolin KH from the Force Curve. Since the angle of shear resistance of the specimen in macro [φ'_r]was around 20°, the shear strength of macro and micro were not equal. Even when the micro strength was simply integrated, it didn't equal the macro strength.

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N-isopropylacrylamide (NIPAAm) composites intercalated with Li-, Na-, K-, tetramethylammonium-, n-octyltrimethylammonium- and trimethylstearylammonium saponites, Na-montmorillonite and Na-hectorite were prepared by solid-liquid and solid-solid reactions. The intercalation was confirmed by powder X-ray diffraction and ignition loss. For solid-liquid reaction the interlayer spacing expanded to c.a. 0.4nm in the Na-saponite treated by 8.8-14mmol L^<-1> NIPAAm aqueous solutions and 0.7nm in that treated by 18mmol L^<-1> solution, indicating a monolayer structure of the NIPAAm constructed in the interlayer space at low intercalation level changes to a pseudo-bilayer structure at high intercalation level. It is presumed from the expansion of interlayer spacing that the amount of intercalated NIPAAm is larger in saponite than hectorite and montmorillonite when they are treated by the solution of the same concentration of NIPAAm. In saponites, the amount of NIPAAm adsorbed was decreased largely by the exchange from Na^+ to bulky organic cations such as, n-octyltrimethylammonium- and trimethylstearylammonium. On the other hand, the cation exchange among alkali metal ions affects scarcely to the amount of intercalation. The dominant interaction which governs NIPAAm intercalation is considered to be hydrogen bonding between N-H in NIPAAm molecule and oxygen at the surface of clay layer. In the case of tetramethylammonium- and n-octyltrimethylammonium-saponite, the nanocomposition with NIPAAm in solid-liquid reaction was dominated by adsorption into micro- and mesopores in the clay.

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Fluoride adsorption by a variety of oxides consisting of aluminum (Al), iron (Fe), titanium (Ti), and manganes (Mn), montmorillonite, kaolinite, and two allophanes were investigated in respect of solution pH, so as to grasp behavior of fluoride in environments and fixation mechanisms by the minerals. Almost all of the total fluoride species (T-F) are removed from the solution by anatase, amorphous TiO_2 and goethite in acidic condition and the removal percentages apparently decreased with increasing pH. Little fluoride adsorbed on amorphous MnO_2 and birnessite in the pH range (pH>4.0). In the minerals which contain Al as a major component, the fluoride ions (HF or F^-) removals were apparently higher than T-F removal in acidic condition. Especially, the removal percentage of HF or F^- on montmorillonite, natural allophane and synthetic allophane from the solutions showed nearly 100% in the pH range from 2.0 to 6.6. These phenomena meant that considerable amount of fluoride in the solutions in low pH range existed as soluble fluoro-aluminate complexes (AlF_n^<3-n>), leached from the minerals after sorption of fluoride onto surface Al-OH functional groups.

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The frictional force and viscosity of high-purity montmorillonite were measured with an Atomic Force Microscope (AFM). The results confirmed that both the coefficient of friction (μ) for Na-montmorillonite and that for Ca-montmorillonite exhibit a graded decrease with an increase in relative humidity (RH). The results also showed that, in terms of its relationship with temperature, the coefficient of friction (μ) for Na-montmorillonite increases with an increase in temperature when the RH is 30% or higher but remains constant regardless of temperature when the RH is 20% or lower. The coefficient of friction (μ) for Ca-montmorillonite, on the other hand, increases with an increase in temperature regardless of the RH. It was confirmed that the viscosity of both Na-montmorillonite and Ca-montmorillonite has a graded increase with an increase in the RH. The viscosity of Na-montmorillonite remains constant regardless of temperature when the RH is 20% or lower, but decreases with an increase in temperature when the RH is 30% or higher. The viscosity of Ca-montmorillonite, however, diminishes as the temperature increases regardless of the RH. And finally, a comparison of frictional forces in the macro and micro regions showed that the coefficient of friction (μ) in the macro region calculated from the direct box shear test does not match the coefficient of friction (μ) in the micro region measured by using an AFM.

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We prepared a hardened geopolymer paste by treating a mixture of fly ash and alkali silicate solution at 80℃ for eight hours. X-ray diffraction and ^<29>Si-NMR spectra indicated that the hardened geopolymer paste was amorphous with a zeolite-like structure. Cation exchange examination indicated that its exchange capacity was 150-170, 200-230, and 250-300meq/100g against alkali/H_2O ratios of 0.10, 0.15 and 0.20, respectively. The ion selectivity of the hardened geopolymer paste follows the order of Pb>Ba>Sr>K>Na. Except in the case of Cr-adsorption (which causes structural change), the selectivity of divalent ions is greater than that of monovalent ions, and ion selectivity increases in the order of ascending atomic number for the identical valence.

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The Akkeshi Bay and Lake Akkeshi area faces the Pacific Ocean along the eastern coast of Hokkaido, Japan. A number of landslide-related disasters have occurred within this area. The bedrock of the landslides consists primarily of pelitic rocks, sandstone, conglomerate, volcaniclastic rocks, and andesite lava of the 3,000-m-thick Upper Cretaceous-Paleogene Nemuro Group, which comprises the Nokkamappu, Otamura, Monshizu, Oborogawa, Semposhi, Shiomi, and Konbumori Formations in ascending order in the west coast area of Akkeshi Bay. The bedrock of the 1959 Semposhi Slide is primarily composed of siltstone from the Upper Siltstone Member of the Semposhi Formation. Mineral composition of the landslide clay is primarily composed of calcite, with lesser interstratified illite/smectite minerals, quartz, plagioclase, kaolin minerals, and illite. The smectite-layer content and Reichweite of the interstratified illite/smectite minerals in the landslide clay is approximately 90% and g=0, respectively. It is therefore suggested that the landslide occurred within siltstone from the Upper Member of the Semposhi Formation is closely related to the interstratified illite/smectite mineralization by diagenesis. The landslide is classified as a diagenetic zone landslide on the basis of bedrock geology.

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