Unsaturated soil is a three-phases assembly, i.e., soil particle (solid phase), pore-air (gas phase), and pore-water (liquid phase). In this paper the number of soil particles per unit volume, the number of contact points of soil particles per unit area and the number of contact points per a soilparticle (coordinate number) are used as basic quantities to establish a new comprehensive soil mechanics for unsaturated soils, which can organically analyze the water retention, pore-air permeability, pore-water permeability, compression and shear behaviors based on the statistics and probability theory. For pore-air and pore-water the elementary particulates model is introduced to derive the soil-water characteristic curve and the coefficients of pore-air and pore-water permeability. Forsoil particles the Markov process is applied to analyze the continuous change in contact angles at contact points of soil particles and the ratio of disappearance&appearance is introduced to estimate the discontinuous change in the number of contact points.

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  Kobe airport was constructed offshore Kobe port by reclamation and was opened at February 2006. The Holocene clay layer had accumulated sickly under the seabed that the airport was constructed, and it was important how the deformation of its soil layer influenced the airport facilities. Its deformation appeared to compose of the vertical and horizontal settlement, and the effective deformation analysis model was established by previous knowledge regard to predict its deformation, and besides, for grasping the deformation property the various monitoring apparatus were set up and the measurement of them had been made, and the analysis model had been reviewed by the measuring data. It was resulted that the soil deformation became to be predicted rightly and the improvement direction was presented.

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  In this paper, we report the differences between frost susceptibility of rock and soil. Our research consists of two types of frost heave tests. One test uses solid rock samples. The other uses artificiallyshattered, grainy rock samples. We conducted these two types of frost heave tests to investigate the differences between frost susceptibility of solid rock and grainy rock. From the test results, non- frostsusceptible rock did not change its frost characteristics in solid and grainy condition. On the other hand, the frost characteristics of frost-susceptible rock changed dramatically in solid and grainy condition.
  These facts above indicate that the frost susceptibility of rock and that of soil are different.

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  A parallel plate model has been widely applied to a model evaluating for flow and mass transport in a single fracture. However, fracture aperture in a rock mass heterogeneously distributed affects hydraulic and mass transport behavior. There are underlying causes of the method to define the representative parameters such as transmissivity and aperture used for a parallel plate model, because of a limited number of data based on precise experiments. Therefore, to obtain the precise data sets for evaluating a hydraulic and mass transport properties of a single fracture, we employed an optical measurement system for measuring aperture and tracer concentration, and a series of experiments such as aperture measurement, hydraulic and tracer tests for the transparent replica specimen was conducted. As a result, 0.15 mm high spatial resolution of fracture aperture distribution, quantitative tracer distribution in 10 cm size of fracture and a breakthrough curve under the same conditions as hydraulic tests were obtained.

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  This paper describes pullout resistance characteristic of a strip embedded in a cement-treated soil. In this study, a test apparatus was newly developed to pullout flat and rib strips from a reinforced soil wall model such as the Terre Armee wall. A series of tests was performed on various soils cured under different conditions of vertical stress, cement content and curing time, and so on. As a result, the pullout resistance of non-standard soil whose fine fraction content is over 25% increased remarkably by the cement treatment. Therefore, such the soil can be utilized as backfill soil in reinforced soil walls. The pullout resistance of cement-treated soil increases with increasing the vertical stress, the cement content and the curing time, respectively. Also, stiff behavior of the soil observed from the tests may be due to breakage of cementation developing in contact between a soil and a flat strip. There seems to be correlations between the pullout resistance and the unconfined compressive strength for cement-treated soil. Based on the correlation, the pullout resistance of strip from cement-treated soil can be estimated by the unconfined compression test.

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  In the current concept of repository for radioactive waste disposal, compacted bentonite will be used as an engineered barrier mainly for inhibiting migration of radioactive nuclides. Hydrogen gas can be generated inside the engineered barrier by anaerobic corrosion of metals used for containers, etc. If the gas generation rate exceeds the diffusion rate of gas molecules inside of the engineered barrier, gas will accumulate in the void space inside of the engineered barrier until its pressure becomes large enough for it to enter the bentonite as a discrete gaseous phase. It is expected to be not easy for gas to entering into the bentonite as a discrete gaseous phase because the pore of compacted bentonite is so minute. In this study, a method for simulating gas migration through the compacted bentonite is proposed. Coupled hydrological-mechanical processes can be analyzed using the model of two-phase flow through deformable porous media. By comparing existing gas migration test results with the calculated results, it was revealed that the proposed method can simulate gas migration behavior through compacted bentonite with accuracy.

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  Application of drinking water sludge to geotechnical construction is greatly anticipated for projects such as road infrastructure, but durability of the material must be evaluated. Poly-aluminum chloride, a flocculating agent contained in drinking water sludge, is expected to leache as aluminum and influence interparticle aggregation. This study investigated the compressibility and hydraulic conductivity of drinking water sludge after wet.dry processing with Al leaching using constant strain rate consolidation testing. Long-term leaching behaviors were evaluated using serial batch leaching tests. For Al release of less than 0.4 mg/kg, results show almost no influence on the compressibililty and hydraulic conductivity of drinking water sludge. The wet—dry processes corresponded to 3.16 years’ progress at an actual site.

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  The authors examine an anti-liquefaction measure method of construction to make the ground unsaturation positively. About the liquefaction strength of partially saturated sand, some study examples are examined, but there is no such precedent that the examination that paid its attention to the study that authors used a non-disturbance sample of the true ground for and the disorder of the sample was still carried out. Therefore, in this study, authors sampled disturbance and non-disturbance sample from the ground which became a liquefaction object and authors adjusted test body color saturation by the pressure plate method which triggered the air pressure of the slight low pressure and repeated it and carried out a triaxiality examination and examined a difference of the liquefaction strength increase by the difference of the sample. In addition, for the ground of heterogeneous color saturation distribution, authors examined the effectiveness of the unsaturation by the gravitational field vibration level experiment that used shear box shaking table tests. As a result, authors understood that outbreak of the liquefaction was restrained by making the ground the state that was unsaturation without affecting uniformity of the color saturation.

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  Collapse of slope formed from volcanic soils has been frequently caused in Hokkaido, Japan. This study aims at clarifying failure mechanism of volcanic slope caused by both rainfall and freeze-thaw action. In particular, the effects of freeze-thaw action, slope angle, density and friction of impermeable layer in the slope on mechanical behavior were detailedly investigated on volcanic slopes having several shapes. The results showed that; surface slope failure depends strongly on slope angle, the friction characteristics of impermeable layer and rainfall intensity, and the formation of frozen layer in spring season and the softening of slope by freeze-thaw action in summer season are important for evaluating the stability of volcanic slope.

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  The distribution of groundwater properties is important for understanding of the deep underground hydrogeological environments. This paper proposes a geostatistical system for modeling the groundwater properties which have a correlation with the ground resistivity data obtained from widespread and exhaustive survey. That is, the methodology for the integration of resistivity data measured by various methods and the methodology for modeling the groundwater properties using the integrated resistivity data has been developed. The proposed system has also been validated using the data obtained in the Horonobe Underground Research Laboratory project. Additionally, the quantification of uncertainties in the estimated model has been tried by numerical simulations based on the data. As a result, the uncertainties of the proposal model have been estimated lower than other traditional model’s.

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  The present study aims to convert the space of former municipal waste landfills to an urban development. This aim is however difficult at this moment because existing landfills have such significant problems as long-term subsidence and low rigidity. Due to lack of foregoing comprehensive studies on such mechanical properties of municipal waste, the authors collected real waste from a landfill in Tokyo and carried out consolidation as well as shear tests in the laboratory. This text introduces the results of those tests concerning compressibility, shear rigidity, and behavior under seismic load. It is noticeable that municipal waste behaves in a very similar manner as soil mechanics state.

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  Identification of such hydraulic properties as absolute permeability, porosity, relative permeability, and capillary pressure has been conducted in this study with measurement data acquired in a hydraulic confining system of the compressed air energy storage (CAES) which was excavated in fractured rock mass. Capillary pressure curve and relative permeability curves as the function of water saturation were composed of the combination of two equations by van Genuchten, Brooks & Corey, Mualem, and Burdine. The results indicate us that the shape of the gas relative permeability which could reproduce measurement data of gas leakage amount from the cavern is convex upward. Since the shape of relative permeability curves for sedimentary rocks are generally convex downward, this shape might be characteristic for fractured rock which could have small porosity and therefore have relatively larger permeability than sedimentary rock.

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  It is well known that effective pressure and strain relation is strongly dependent on the strain rate and its dependency is very important to predict settlement caused by consolidation including secondary con-solidation. Many researchers have proposed strain rate dependent models, including so called Isotach model, whose compression curves on given strain rates are parallel in ε-log p’ relation and a parameter of strain rate dependency is expressed as the function of the strain rate. To examine the strain rate dependency of cohesive soils on compression curves under very slow strain rates, a Slow Constant Rate of Strain (SCRS) oedometer was developed to attain the minimum strain rate of 3.8 × 10^-10 s^-1. SCRS test was carried out on five different cohesive soils of intact as well as reconstituted samples. It is found that although compression curves of all clays strongly depend on the strain rate, the Isotach model can be applied to only Osaka clay.

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  In this study, the field liquefaction experiment was carried out to examine the effect of partial soil improvement by Chemical Grouting Method as a countermeasure for liquefaction. This paper reported the undrained shear behavior and volumetric straine with dissipation of excess pore water pressure in chemical grouting-improved and unimproved sandy soil in the experimental site by conducting a series of tri-axial tests. Finally, it was found that chemical grouting method reduced volumatric strain compared with unimproved sand after liquefaction. Additionally, the effect of partial soil improvement, focused on the residual subsidence measured in the experimental test, was estimated based on the results of laboratory tests.

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  The liquefaction resistance of sands depends on the density, and the magnitude and wave form of the shear stress. In this paper, cyclic torsion shear tests and cyclic simple shear tests are conducted to study the influence of the wave form of shear stress on the liquefaction resistance using 11 shear wave forms. The test results are investigated on the load irregularity factor which is the ratio of the liquefaction strength of an irregular wave to that of a sinusoidal wave. The load irregularity factor is analyzed by using the effective wave number which is defined as half the number of half waves of shear stress larger than 60% of the maximum shear stress. Also, the wave form correction factor is proposed using the effective wave number to consider the irregularity of the shear stress wave in the liquefaction prediction method based on the grain size distribution and the standard penetration test N-value.

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