The establishment of a geosynthetics-reinforced soil wall having vertical faces using concrete panels is desired. Concrete panels lack in their supporting strength; thus they are supported by various reinforcements. Therefore, the displacement and stability of each step of concrete panels must be studied, together with the stability of whole reinforced soil walls. In the study, a relationship between the displacement of the wall whose area is equivalent to that of one panel and the tensile force distribution characteristics has been clarified by means of three kinds of reinforcements having different tensile stiffness using a small-scale movable retaining wall device.

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Influence of freezing and thawing on the mechanical properties of rock is investigated. The rocks used for the examination are Kurihashi-granite, Funyu-tuff and Tage-tuff. The difference between the intact and degraded specimens is investigated for mechanical parameters and distribution of strain by unconfined compression test. The strain distribution is observed through the image processing. As the results of the test, it is found that the change in mechanical behaviors of Kurihashi-granite is quite different from that of Funyu-tuff. Granite and Tage-tuff become brittle with degradation while Funyu-tuff becomes hard rock. It is inferred that the volumetric strain distribution may be good measure for failure.

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Estimation formula for rock mass deformability in borehole jack test initially derived by Goodman has been modified by Hustrulid and Amadei et al. But their solitions are approximately obtained as the first fundamental problem. This paper presents forrnula from the exact solution by the mixed fundamental problem. In the latter half, Numerical calculation by their approximate and our exact solutions are performed and quantitative differences between them are shown by graphical representation.

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In general, gravelly soil layers are considered to be less susceptible to liquefy during earthquakes than sandy soil layers. However, traces of liquefaction that occurred in gravelly soil layers are discovered recently.
In this paper, firstly, detailed site investigation was conducted at the site where a diluvial gravelly soil layer might have liquefied during a strong earthquake. As a result, no evidence showing that the gravelly soil layer at the site had liquefied was found. Secondly, relationships between maximum shear stress ratios during earthquakes and penetration resistance were investigated for both liquefied sites and nonliquefied sites. It was revealed that the boundary between liquefied sites and nonliquefied sites could be approximated by existing equations.

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The present study newly derives temperature distribution inside a ground in the case where ground water flows in a uniform manner inside the ground which has a cooling surface and a heated surface disposed in parallel each other sandwiching the ground, and a method to calculate the growth of frozen soil to be produced in the region is shown.
As anapplication of the theory, it is shown that, also in the case where a lot of ground water is gushed out from the bottom in a freeze wall cofferdam, a freezing region locally undergoes ground improvement measures so that construction works can be safely executed.

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The ground investigated in this research had been treated by Flyash-Gypsum-Cement (FGC) using Deep Mixing Method in order to get high resistance against heaving and lateral deformation. Cone penetration test (CPT), pressuremeter test, and seismic velocity logging test (VST) were carried out on the treated ground. Further, laboratory unconfined compression test (UCT) of the treated soil was also performed using the samples retrieved from rotary triple tube sampler (RTS).
This paper discusses the applicability of these in-situ testing methods, in combination with laboratory test, in evaluating the engineering properties of the treated ground. The results of shear strengths obtained by CPT and UCT have been compared. It is found that in combination with laboratory testing, CPT testing is capable of properly evaluating the strength of a treated soil. The value of modulus of rigidity and shear strength of samples obtained from RTS are smaller than that from in-situ tests, indicating that these samples might have been disturbed.

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Mud soil sedimented in a irrigation pond generally is high water content and very soft clayey soil. Recently, it is necessary to develop the method for utilization of such a soil, as there is little space to abandon it as industrial waste. In this paper, to confirm the applicability of the mud soil as the embankment material to repair the irrigation pond dam, a series of unconfined compression and triaxial compression tests and so on was performed to investigate the strength characteristics and stress—strain relation of cement-stabilized pond mud soil. Test results shows the follows. The stabilized-mud soil is applicable to the embankment material if the mud soil was embanked by crushing and compacting after initially stabilized with cement-stabilizer. However, it is important to controlled the initial stabilizing time, the crushed size and strength of initial stabilized-mud soil under construction, because the strength behavior of the crushed and compacted cement-stabilized mud soil is greatly affected by these three factors.

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Through a series of drained triaxial compression tests covering wide-rang confining pressures, the effect of the confining pressure on the deformation and failure of the soft rock are studied. The test sample used is a porous quality tuff called Tomuro-ishi. The material parameters used in the strain softening type elasto-plastic constitutive equation proposed by Adachi and Oka (1992) are obtained from the present test results, and most of them show the confining pressure dependency. Therefore, these parameters are formulated as a function of the confining pressure and the confining pressure dependencies are incorporated in the original Adachi & Oka model. As a result of test simulations, it is shown that the proposed model can well explain the experimental results under different confining pressures in the common basic soil parameters.

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To investigate the failure mechanism of slurry trenches in sandy ground, centrifuge model tests and the elasto-plastic FEM combined with shear strength reduction method (SSRFEM) were performed. From the centrifuge model tests the followings were obtained; the stability condition of slurry trenches was dependent on the length of trench, the lateral confining forces around the sliding block decreased at the yield condition, and the reduction of the lateral confining pressure depended on the slurry trench shape. From the elasto-plastic SSRFEM, the same numerical results as the above were obtained. Lateral confining pressures used for the proposed simple method corresponded to the measured data, and the safety factors obtained by the simple method were appropriate to the test results.

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The shear strength of rock joints are dependent on the their geometrical condition. Up to now, many researchers have proposed formulations which associate the shear strength with roughness profile of rock joints. However, most of them are established under the idealized assumption that no change of the configuration of joint surface occurs. The shear strength of rock joints essentially should be affected by the geometrical change of joint surface during shear procedure. From these viewpoints, this study proposes the analysis method to consider the effect of the change of roughness profile during shear procedure on the shear behavior, and presents the applicability of the proposed method for the prediction of shear strength.

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The purpose of this study is to investigate minutely development processes of construction technology in masonry wall. This study is carried out for understanding the shape of masonry wall correctly and technical factor on stability of constructions. Three index numbers are defined for investigating the process of development masonry wall stone at corner in numerical method. The index numbers D, S, and R are defined for “masonry wall stone process degree”, “masonry wall stone depth ratio”, and “masonry wall stone slope degree”, respectively. As result, the objective numerical judgment with the index numbers is practicable for transition of masonry wall shape.

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Ground near the facing of shield entrance is sometimes improved. In order to determine the extent of the ground improvement, the mechanism for the earth pressure acting on the facing is studied with model tests and numerical analyses. The influences of the process of shaft excavation and the shape of facing on the earth pressure are analyzed. The results of the model tests and numerical analyses show that the active earth pressure on the facing is significantly smaller than that with the Rankine-Rezal method, which is usually used in the conventional design. A new equation for the active earth pressure acting on the facing is proposed and agreed well with the results of the tests where the improved soil body is modeled.

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This paper examines the influences of the aspect ratio on the bifurcation analysis for a non-coaxial and a coaxial Cam-clay model of normally consolidated clays during undrained shear under plane strain condition. The bifurcation analyses are carried out considering the difference between the aspect ratio at the onset of bifurcation and the initial aspect ratio.
As a result, we show the existence of the symmetric bulging mode, which is often observed in the experiment. We also examine the sites where the slip surfaces first occur and the patterns of the slip surfaces by judging from the distributions of maximum shear strain

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In the construction of embankment with high water content cohesive soil, geotextile is often used in order to accelerate the consolidation of embankment In order to use geotextile efficiently, the effect of geotextile on the stability of embankment should be evaluated with high accuracy. In this paper, coupling analysis of limiting equilibrium state is conducted considering the effect of geotextile to accelerate consolidation, the effect of geotextile are examined. Main conclusion is as followings. 1) The relationship between stability of embankment and placing condition of geotextile is different according to the shape of embankment. 2) There is efficient placing condition of geotextile to stabilize embankment.

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On the earth pressure reduction of rigid culverts using expanded polystyrol, field test results were reported, while results without such material were also presented in various papers. Evaluation of these data clarified the elements determining the magnitude of vertical earth pressure on the culvert without expanded polystyrol, and, for cases with this compressive material, the relationship between placement conditions of the material and vertical earth pressure reduction effect. The previous papers mainly addressed the compression settlement of the expanded polystyrol. Studying the compression settlement of the backfill, the present paper discusses the relationship between compression settlement around culverts and vertical earth pressure reduction effect.

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In this paper, since there are no grading specification on gap-grading for base course materials for road at present, we studied the mechanical properties of gap-grading base course materials, based on many laboratory CBR test results, comparing to the mechanical properties of continuous grading materials, and clarified that the mechanical properties of gap-grading materials are not inferior to those of continuous grading materials. Further, studying the application of gap-grading materials to base course materials for road in detail, we specified and showed the gradation range of gap-grading materials applicable to base course materials and subbase course materials. Besides we also described matters to be attended to when gap-grading materials are used.

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This paper describes the mechanism of slope displacement using the results of long-term monitoring of a large excavated rock slope. The study also evaluates the influence of joint sets on slope behavior by numerical analysis. The stability of a large excavated rock slope is greatly influenced by the joints and weak layers in the rock, and the geometrical relationship between their positions and the excavated surface. It is important not to fail to notice signs of instability at early stage of excavation with results of long-term monitoring. Based on the deformation behavior observed by monitoring. the need of actions should be determined such as additional geotechnical investigations, stability analysis, and design modifications and revisions.

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In order to grasp the effect of faults to the stability of dam foundation, gravity dam modeling test machine has been developed. Using this apparatus, some tests are carried out, namely no-fault foundation model and one-fault foundation models. In the case of one-fault foundation models, fault is located in upstream edge, center and downstream edge of the dam model. Based on the experimental results, it is confirmed that the stress distribution along the bottom of dam is largely affected by the location of fault. In downstream edge fault model, the stress concentrated at toe, and the failure strength remarkably becomes lower than no-fault model. Both central fault model and upstream fault model, the effect of fault to the stress distribution is small and failure strength is almost the same as no-fault model.

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Although it is widely recognized that lime-stabilized and cement-stabilized soil restrict frost heave, little is known about it's mechanism. It is generally thought that a decrease of the permeability or an increase of the bonding strength between soil particles contribute to the restriction of frost heave in stabilized soil.
In this paper, changes of the permeability and pF characteristics in lime-stabilized soil were investigated and their effects on frost heave were discussed. As a result, it is found that the permeability and the bonding strength do not affect on the frost heave very much. However, there was a correlation between the amount of adsorbed water obtained by pF test and the frost heave.

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It is well known that soft rocks are disintegrated by repetitions of drying and wetting in nature. But, the disintegration and settlement behavour of these materials are not known satisfactory. Also the relationship between the results of in-situ exposure tests and that of slaking tests in laboratory are not known. Then Mizunami mud rock is used to carryed out in-situ exposure tests in 7 years and slaking tests in this study. The results of this study are as follows: (1) progress of the settlement and particle breakage are confirmed by both test results, (2) a unique relation is recognized between exposure periods and slaking cycles.

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Earth structures with precasted arch culvert and Terre Armee wall have been constructed in many parts of Japan. However, in a seismically active area like Japan, there is a need to study the seismic and shaking characteristics of the said structure. In this research, shaking table tests under two directional shaking in a horizontal plane were conducted to examine the effects of the shaking conditions, i. e., between one direction and two directions, on the dynamic stresses that develop in a 3-hinge arch and on the displacement of Terre Armee wall. Furthermore, the effect of friction between the ground and arch or strips was examined. Based on the results, the factors which are necessary to evaluate the seismic stability of the said structure are confirmed.

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The water retention curve, which represents the relation of water content and suction value of soils, cannot be uniquely specified even in the same material. It shows the hysteresis loops between the drying and the wetting process. And also it varies depending on initial conditions. In this paper, the dependency of the water retention curve on void ratio is examined. The void ratio dependency dominantly influences the air and the water entry characteristics of unsaturated soils. Finally an attempt to quantitatively express the water retention curve is made considering the void ratio dependency. The model proposed in this paper can be applied to prediction of unsaturated soil behaviors.

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This paper presents the case study of a high embankment constructed by masa-soil (weathered granite rock) in granite district. In this study, a series of compression settlement and triaxial compression tests were performed to investigate the settlement properties, stress-strain relation and strength characteristics on the embankment material (masa-soil).
Test results shows that the compaction degree of the embankment more than D_C=90% was effective for decreasing the settlement due to seepage, and the Mohr-Coulomb strength parameter of the embankment material was satisfied sufficiently with the design specification. The stability of high embankment slope was also estimated by the relation between the field observation results of embankment slope and the stress-strain curve of embankment material obtained by laboratory tests.

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In the present study, it was attempted to apply the density-measurement method by using a split-spoon sampler with built-in tube to a decomposed granite soil, and to observe the variations in soil constants economically and accuracy. Dry density ρ_df of a decomposed granite soil sample determined by sand replacement method and that ρ_ds2 determined with the help of a split-spoon sampler with built-in tube were compared to see a close correlation. In the next step, the relationship between angle of shear resistance φ_d and dry density ρ_d of an undisturbed sample of decomposed granite soil was combined with that between ρ_df and ρ_ds2 to formulate a system for estimating in-situ φ_d for decomposed granite soil. This system was proved with accuracy.

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Before construction of any structures on surface or subsurface of alluvial clay layer, the cement mixing methods have been used frequently to construct an improved layer at certain depth of ground. However, the confirmation of improved layer is performed by only boring and laboratory testing. The present paper are discussed about the confirmation method using s-wave reflection method, and it is tried that the S-wave distribution of improved layer is obtained by velocity analysis. Furthermore, the relation between the uniaxial compression strength of improved layer specimens by boring and S-wave velocity of improved layer by the velocity analysis are discussed, and the continuous distribution of uniaxial compression strength on improved layer can be accurately obtained.

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The authors developed a simple and general displacement field measuring method using a technique for image analysis. The proposed method, named CCIP method, requires no target installed in the model to measure displacement field on sand. A newly developed correction method for distortion of image needs no longer information than the coordination of four datum points covering the analyzed zone. These features can reduce labor in the preparation of model sand and the analysis of displacement fields. An evaluation of accuracy and two examples are presented in this paper. The results show that the method can measure deformations in sand within an accuracy of 2 pixels of the images employed.

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