This study attempted to evaluate the uplift resistance of belled anchor with dense sand, by comparing the results of experiment with finite element analysis. The test was conducted in normal gravity condition and was performed under axisymmetric condition in embedment ratio (h/D; h: depth of sand mass, D: Anchor diameter) of two. The circular belled anchor was 5cm in diameter and belled angles with 0, 27, 45, 63, 72 and 81 degrees. The finite element analysis employed a constitutive model in which nonassociated strain hardening-softening elasto-plastic material was assumed and an effect of shear band thickness was introduced. Fromthe study, when the belled angle was from 60 to 70 degrees, the maximum uplift resistance was the largest in all belled anchors. The difference of maximum uplift resistance was attributed to the different extent of the progressive failure with shear band propagation in sand mass and friction on the surface of anchor.

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Surface soil moisture is an important variable which significantly affects the hydrological environment of region. It is necessary to better understand the spatial distribution of surface soil moisture for an accounting of the water and theenergy balances at the land-atmosphere boundary. In this paper, the characteristics of spatial distribution and the time stability of sampling locations for sloping grassland filed were discussed using the field data obtained by 100 cm3 core samplers. As a result, the variability of surface soil moisture decreased with an increase in water contents, and its distribution was led not to show the normal distribution with the decrease of water contents. The area-scale mean water contents at each area indicated that the mean water content at the low area was the highest, and that the surface soil moistures were different according to each area. The coefficient of variation for surface soil moisture at the slope areawas the largest. It was also implied that the sampling location which always exhibited the field-scale mean water content irrespective of a temporal variation existed using the concept of time stability. However, it was clear that a lot of sampling events were needed for the application of the concept.

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This study investigated the effect of soil water stress on the growth and yield parameters of sugarcane and revealed a suitable critical pF value for optimum water use in sugarcane production. Six different pF levels [pF = Log (kPa×10.197)], viz. 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0, were tested on dark reddish Shimajiri Maji soils. The seasonal water consumption through evapotranspiration (ET) was significantly (P<0.01) higher at the pF range between 1.5 and 2.0 while that was significantly lower beyond the pF 3.5. Growth parameters (viz. stalk length, cane diameter, leaf area, leaf number, root dry weight, specific leaf weight, relative water content etc.) and cane yield were not detrimentally affected at pF range between 1.5 and 3.0. However, the above parameters significantly decreased with soil water stress beyond the pF level 3.5. The pF levels from 2.0 to 3.0 provided higher water use efficincy (WUE) and thereafter WUE decreased significantly (P<0.01) by the deficit soil water at the pF 3.5 to 4.0, giving its highest value at pF 2.5. Soil water stress at pF 3.5 to 4.0 increased the brix % in cane juice with decrease in total sugar production due to low cane yield at this pF levels. Over all results suggest that the effect of soil water at pF 3.0 tends to initiate the retardation of growth and yield parameters of sugarcane. In terms of water production function, the lowest acceptable cane yield and sugar productions were obtained at pF 3.3. This pF value could be considered as the critical pF level for irrigating sugarcane. However, a critical pF value between the pF range 3.0 and 3.5 can provide adequate soil water for profitable sugarcane production.

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The effect of fillet in concrete gravity dam was studied by the finite element method. In the case of only changing the slope o fillet, in 2-dimensinal analysis and 3-dimensinal analysis, in fillet and the part close to it, the maximum principal stress receive bigger influence, and in those areas, the bigger the slope of fillet is, the smaller maximum principal stress (from 0.766MPa to 0.607Mpa) and the displacement of upstream face (the maximum from 3.88mm to 3.29mm) becomes. In the case of only changing the slope of fi llet, comparing with 2-dimensinal analysis, maximum principal stress in 3-dimensinal analysis is fairly small (average difference 0.499Mpa), the displacement of an upstream face is fairly small (average difference 158mm) too. In the case of the slope of fillet changed largely and the slope of upstream face changed small, in 2-dimensinal analysis, maximum principal stress becomes small (from 0.703MPa to 0.627Mpa), and the displacement of upstream face becomes small (the maximum from 3.48mm to 3.43mm) too. It was also studied that effect of property of foundation, Safety of concrete, and effect that fillet gives to stability of bod of dam.

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Rapid underdrainage is necessary for the cultivation of upland crops in fields converted from clayey paddy fields in the Hokuriku Area. Therefore, in order to accelerate subsurface drainage shallow underdrain pipes were constructed at about 0.4m below the soil surface at intervals half that of ordinary underdrain pipes installed at about 0.7m deep. In this paper, the characteristics of the system's underdrain discharge during heavy rainfall over a period of 5 years were investigated. The following results were obtained. In the early years of the converted field, the total underdrain discharge was almost shallow drain discharge in the plot having an ordinary drain combined with a shallow drain system and the peak underdrain discharge was greater than that in the plot having only an ordinary underdrain. Surface stored water and excess water in the plow layer soil were drained quickly and effectively by shallow underdrainage. Following this, ordinary underdrain discharge increased year by year. After 5 years, the peak underdrain discharge of the plot having the underdrain system was nearly equal to that ofthe plot that developed macropores such as shrinkage cracks. Ordinary underdrainage and shallow underdrainage play an important role in eliminating excess water in the plow layer soil and lowering the groundwater table.

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The colloidal stability of volcanic ash soils pretreated in different ways was investigated in relation to pH, and the functions of imogolite, soil organic matter, iron, and aluminum were discussed. Fresh topsoil coagulated in acidic conditions, and dispersed in neutral and alkaline conditions. While volcanic ash soil bears positive charge in acidic conditions and negative charge in alkaline conditions, the organic matter in soil bears negative charge in natural soil pH. In the field, volcanic ash topsoil with high organic matter content, therefore, tends to coagulate in acidic conditions and disperse in alkaline conditions. H₂O₂-treated soils dispersed in acidic conditions and coagulated in alkaline conditions. They dispersed near the point of zero charge, and coagulated at higher pH even though the negative charge increased with pH. As a result, we concluded that complex functions of imogolite, iron, and aluminum cause the coagulation of H₂O₂-treated volcanic ash soil in alkaline conditions.

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The project of rural sewerage is spread rapidly and it is contributing largely to the preservation of water quality in agricultural village areas. However, the influence that it exerts on the ecosystem of the river receiving sewage water has not been considered yet. In this paper, we investigated a ‘direct release style’ site where rural sewage was released directly into the river, and we considered the influence of rural sewage effluent on periphyton. The Chl.a that stands for periphyton quantity was high in the remaining area where rural sewage flows in, and a low trend was shown in the downstream area. In the remaining area where rural sewage flows in, species composition of the diatom crowd was changing according to the influence of rural sewage, Saprophilous taxa occupied a great part and, Saproxenous taxa were remarkably few. On the other hand, 19-37% of Saproxenous taxa appeared, although the Eurysaprobic taxa occupied a great part downstream. Diatom Assemblage Index to organic water pollution (DAlpo) that was calculated from diatom was low, and evaluated as polluted in the remaining area, and the downstream area was evaluated as equivalent to the main stream. It was hypothesized that the influence of rural sewage to periphyton is reaching from about 7-10m downstream from the release point.

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The control of thermal cracking due to the heat of hydration of cement is important for gravity dams to secure the required functions such as watertightness, durability and the safety. In this study, temperature, strain and stress of placed concrete were measured in the field by Roller compacted dam-concrete construction method, and then the results of measurement and analysis of thermal stress using 2-D Finite Element Method were discussed. The results are summarized as follows.
(1) There were differences of 4-5°C in K (the ultimate adiabatic temperature rise) and 0.2-0.4 in α(he constant on rate of temperature rise) between tested and calculated constant.
(2) The compressive strength ratio of standard cured specimen to core sample was approximately 1 to 0.75.
(3) In setting the initial value, the value passed one day after placement was more appropriate than one soon after placement.

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In this research, the influence of high temperature to the compressive strength ofnormal concrete used the ordinary Portland cement are investigated with varying the maximum curingtemperature of the concrete at the initial age. As a result, the strength development of concrete changed depending on the curing temperature at its initial age. When concrete was cured from age 1 to 7 days with high temperature, especially 60°C above, the strength development turned out to be very small. The compressive strength of concrete exposed to 60°C below showed almost 90% of standard cured specimen constantly, however, the compressive strength exposed to 60°C above started decreasing significantly. The factors that affect to this phenomenon are considered as, first of all, the difference of hydration products due to the high temperature history, and secondly, interfacial voids occured between the cement paste and coarse aggregate.

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In this research, the strength estimation of concrete stuructre using Schmidt hammer type-N and M is investigated. As a result, it has been clarified that the rebound number of type-N is different from that of type-M. Comparing the standard deviation of both rebound numbers, the variation of rebound number of type-M is smaller than that of rebound number of type-N. Optimum strength range for type-N is considered as 15 to 25MPa, on the other hand, it is possible for type-M to apply to the strength range of 10 to 45MPa. The empirical equations of type-N and h/I for existing concrete structures are suggested from this study.
As for the strength estimation method of both instruments, when calculating the empirical equations using the results of rebound numbers of type-N and M and compressive strength of cores, the accuracy of equations changed depending on the maximum temperature at the initial age of concrete. Furthermore, as far as the concrete structures exposed to 60°C below, accurate estimation of the strength range of 10 to 45MPa is possible with applying the type-N and M.

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Onjaku soil is the weathering product of basalt distributed in Uwaba area, the north western part of Saga Prefecture. The Onjaku soil compacted below optimum water content exhibits collapse-induced settlement when the soil is soaked under an overburden pressure. The present paper describes the changes in the compressibility and shear strength of the Onjaku soil compacted below optimum water content due to soaking under various pressure applied. A decrease of the compression yield stress and compression index, and an increase of the coefficient of volume compressibility were brought about by the release of suction. After soaking the shear strength of Onjaku soil samples below optimum water content dropped to the strength of the samples initially soaking. It is experimentally certified that the suction affects the cohesion of Onjaku soil.

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